فهرست مطالب

محیط شناسی - سال چهل و یکم شماره 4 (پیاپی 76، زمستان 1394)

فصلنامه محیط شناسی
سال چهل و یکم شماره 4 (پیاپی 76، زمستان 1394)

  • تاریخ انتشار: 1395/01/08
  • تعداد عناوین: 16
|
  • مقاله پژوهشی
  • فائزه ترکیانفر*، امیرحسین صادقپور، مهناز میرنوروزی صفحات 721-743
    در این مطالعه با هدف توسعه پایدار، تعیین ساختگاه منتخب پروژه سد و نیروگاه کلات واقع در استان کهگیلویه و بویر احمد از بین سه ساختگاه ممکن انجام شده است. مراحل انجام این مطالعه عبارت است از: شناخت پروژه و محیط زیست تحت اثر، ارزیابی توان اکولوژیکی منطقه، تعیین و بررسی معیارهای محیط زیستی از طریق روش چک لیست و نظر کارشناسی، اولویت بندی گزینه ها با روش تصمیم گیری چندمعیاره و در نهایت انتخاب گزینه بهینه. ارزیابی توان اکولوژیکی ساختگاه ها نشان داد که بیش از 91 درصد محدوده گزینه ها در طبقه مناسب و نیمه مناسب قرار می گیرند؛ بنابراین از نظر توان سرزمین احداث سد در همه ساختگاه ها امکان پذیر تشخیص داده شد. به منظور تعیین گزینه برتر، 9 زیرمعیار محیط زیستی در قالب سه گروه اصلی فیزیکی، بیولوژیکی و اقتصادی- اجتماعی و فرهنگی بررسی و ارزش گذاری شد. نتایج نشان داد که در تعیین گزینه بهینه، به ترتیب معیارهای شرایط لرزه خیزی، وضعیت کاربری اراضی و وضعیت جمعیتی منطقه از اهمیت بیشتری برخوردار است. در پایان با استفاده از نرم افزار Expert Choice و بر مبنای روش ارزیابی چندمعیاره، ساختگاه بهینه با توجه به معیارهای منتخب محیط زیستی معرفی شد.
    کلیدواژگان: اولویت بندی، آثار محیط زیستی، تصمیم گیری چندمعیاره، چک لیست، سد، گزینه بهینه
  • فرناز شیبانی فر، میر مهرداد میرسنجری* صفحات 745-755
    فلزات سنگین از مهم ترین آلاینده های محیط زیستی به شمار می روند که از طریق مناطق ساحلی و رودخانه ها وارد دریا می شوند و از طریق زنجیره غذایی در بدن آبزیان تجمع می یابند. پرندگان در مقایسه با سایر مهره داران نسبت به آلودگی های محیط زیست حساسیت بیشتری دارند. هدف از این مطالعه،اندازه گیری غلظت فلزات سنگین (کادمیوم، نیکل و سرب) در بافت عضله، کلیه و کبد باکلان بزرگ و بررسی تاثیر دو فاکتور سن و جنس در روند تجمع این فلزات در بافت های مختلف است . نتایج نشان داد که بیشترین میانگین غلظت در هر سه اندام متعلق به فلز سرب و کمترین غلظت، متعلق به فلز نیکل است . همچنین، بیشترین تجمع فلزات سنگین در بافت کلیه و کمترین تجمع فلزات در بافت عضله است . نتایج بررسی دو فاکتور سن و جنس در روند تجمع فلزات سمی در اندام های باکلان نشان داد که فاکتور سن در روند تجمع فلزات کادمیوم و نیکل و فاکتور جنس در روند تجمع فلزات نیکل و سرب در اندام های باکلان بزرگ تاثیر گذار است . به نظر می رسد آلودگی فلزات سرب، کادمیوم و نیکل در ذخیره گاه زیست کره حرا برای باکلان بزرگ در حدی نیست که سبب تغییرات رفتاری یا کاهش تولید مثل شود.
    کلیدواژگان: باکلان بزرگ، ذخیره گاه زیست کره حرا، فلزات سمی
  • ناطق لشگری، جمشید قربانی *، سید حسن زالی، قربان وهاب زاده صفحات 757-770
    باطله های زغال سنگ مهم ترین چالش محیط زیستی در مناطق معدن کاری شده به شمار می روند. حضور گونه های گیاهی در شروع احیای این مناطق اهمیت بسیاری دارد. در این تحقیق از ترکیب گیاهی، تنوع و غنای گونه ای و خصوصیات گروه های کارکردی برای ارزیابی پتانسیل احیای طبیعی باطله های زغال سنگ استفاده شد. مطالعه در باطله های زغال سنگ در ذخایر زغال سنگ البرز مرکزی در شهرستان سوادکوه در استان مازندران انجام شد. سه انباشت از باطله که از نظر وسعت و مدت زمان انباشت متفاوت بودند، انتخاب شدند. درصد تاج پوشش گونه های گیاهی در پلات یک متر مربعی برآورد شد. از 43 گونه گیاهی ثبت شده، 22 گونه منحصرا در باطله با وسعت و سن بیشتری رویش داشتند. شاخص های غنا و تنوع گیاهی در باطله جوان تر به طور معنی داری کمتر از سایر مناطق بودند و منطقه مرتعی اطراف بیشترین تنوع و غنا را دارا بوده است. تنوع و غنای گونه ای با افزایش سن متروک ماندن باطله ها افزایش یافت. استقرار اولیه تعداد زیادی از گونه های گیاهی روی باطله ها نشان داد که پتانسیلی از گونه های بومی در منطقه وجود دارد که می تواند در احیای باطله های متروک زغال سنگ استفاده شود. باطله های زغال سنگ که مدت زمان طولانی تری متروک مانده اند از پتانسیل بیشتری برای احیا برخوردار بوده اند.
    کلیدواژگان: باطله زغال سنگ، توالی گیاهی، تنوع و غنای گونه ای، گونه های پیشگام
  • محمد پناهنده*، حبیب فتحی دخت صفحات 771-781
    متریک های سیمای سرزمین می توانند به منظور تشریح ترکیب و ترتیب فضایی سرزمین استفاده شوند. هدف از این بررسی، تعیین میزان و جهت تغییرات در کلاس پوشش گیاهی متراکم منطقه حفاظت شده گشت رودخان است. نخست محدوده تالاب انزلی از تصاویر ماهواره ای لندست مربوط به دو مقطع زمانی استخراج و در مرحله بعد محدوده تقریبی پوشش گیاهی متراکم از طریق تفسیر بصری تصاویر در محیط نرم افزار Ermapper7.1 تهیه شد. سپس این ناحیه در قالب دو کلاس پوشش گیاهی متراکم و بدون پوشش گروه بندی شد. در گام دیگر، پس از جداکردن محدوده منطقه حفاظت شده گشت رودخان، کلاس پوشش گیاهی متراکم آن نیز تهیه شد. بعد از آن لایه های وکتوری پوشش گیاهی ساخته و به منزله ورودی اکستنشن Patch Analyst به منظور محاسبه متریک ها استفاده شدند. نتایج بیانگر تغییرات قابل ملاحظه در متریک های مجموع مساحت های تمام لکه های همسان (CA)، تعداد کل لکه ها (Numps)، متوسط اندازه لکه ها (Mps)، متوسط لبه لکه ها (MPE)، تراکم لبه (ED) و کل لبه (TE) در دو سطح لکه اصلی پوشش گیاهی متراکم حوزه تالاب انزلی و سطح کلاس پوشش گیاهی متراکم منطقه حفاظت شده است که با توجه به جهت تغییرات بیانگر افزایش فرایند تکه تکه شدن پوشش گیاهی متراکم است.
    کلیدواژگان: تالاب انزلی، تکه تکه شدن، سیمای سرزمین، سنجه
  • رشید سعید آبادی، شعیب آب خرابات، محمد سعید نجفی* صفحات 783-798
    هدف از این مطالعه شناسایی و تحلیل موقعیت رودباد جبهه قطبی و شار رطوبت در ارتباط با بارش های سنگین غرب ایران با استفاده از روش همدید است، که چهار الگو در این زمینه شناسایی شد. در همه الگوها در روز رخداد بارش، ناحیه چپ خروجی (ربع دوم) هسته رودباد جبهه قطبی (که بیشترین واگرایی سطوح بالا و همگرایی سطوح زیرین جو را فراهم می کند) بر فراز آسمان غرب ایران قرار گرفته است. نتایج نشان می دهد که در روز رخداد بارش، محور هسته رودباد در منطقه مورد مطالعه دچار انحنای نصف النهاری شده است که این موضوع از دو جنبه به صعود شدیدتر هوا کمک می کند. این آرایش هسته رودباد سبب وزش دمایی گرم به مناطق تحت تسلط نیمه خروجی رودباد می شود و این شرایط صعود و همرفت بیشتر هوا را سبب می شود و از دیگر سوی متمایل شدن هسته رودباد به وزش نصف النهاری موجب می شود تا جریان هوا دچار چرخندگی انحنایی شود و صعود حاصل از این چرخندگی انحنایی به چرخندگی برشی ناشی از شیب سرعت در ربع دوم هسته رودباد افزوده شود و صعود هوا را تشدید کند. منابع تغذیه کننده رطوبتی این بارش ها نیز در مرتبه اول دریای عرب سپس دریای سرخ، خلیج فارس و دریای عمان است.
    کلیدواژگان: بارش سنگین، رودباد جبهه قطبی، سینوپتیک، شار رطوبت، غرب ایران
  • علی اکبر شمسی پور *، الهام اشرفی، مرضیه علیخواه اصل، خسرو اشرفی صفحات 799-814
    مدل سازی پراکنش آلاینده ها با لحاظ انواع خصوصیات منابع انتشارات، شرایط آب و هوایی و موقعیت مکانی منبع آلودگی شاید قابلیت ارائه خروجی های مطلوب برای برنامه ریزی و مدیریت کاهش و کنترل آلاینده های منتشره را داشته باشد. در پژوهش حاضر از عناصر اقلیمی (دما، رطوبت، جهت و سرعت باد) با مقیاس روزانه برای سال 2010 ایستگاه دوشان تپه استفاده شد. متغیرهای انتشارها و خصوصیات منبع انتشار آلاینده (ارتفاع دودکش، سرعت و دمای گاز خروجی، نرخ انتشار جرم آلاینده و...) از کارخانه سیمان، با توجه به نتایج نمونه برداری های فصلی از 12 منبع آلاینده دریافت شد که همگی از نوع دودکش بودند. مدل سازی رایانه ای پراکنش آلودگی هوا با مدل AERMOD انجام شد. مدل برای ارزیابی آثار نشر از منابع مختلف صنعتی در فواصل کمتر از 50 کیلومتر به کار گرفته می شود. یافته ها از مدل سازی پراکنش آلودگی هوا نشان می دهد که بیشترین آثار ذرات معلق کمتر از 10 میکرون در فاصله 1 تا 5 کیلومتری از کانون انتشار رخ می دهد. در تابستان میزان ذرات ورودی به تهران از منشا کارخانه افزایش بیشتری دارد و تا فاصله 15 کیلومتری از مبدا را پوشش می دهد. پیشنهاد می شود کارخانه سیمان در خطوط تولید خود به واسطه کاهش چشمگیر غبار از فیلترهای هیبریدی بهره ببرد.
    کلیدواژگان: کارخانه سیمان، ذرات معلق، مدل سازی آلودگی هوا، مدل AERMOD
  • فریدا ایرجی آسیابادی*، سید احمد میرباقری، علی اصغر بسالت پور صفحات 815-825
    گیاه پالایی یکی از روش های زیستی ارزان، موثر و دوستدار محیط زیست برای کاهش آلودگی های نفتی خاک است، اما اندازه گیری کمی غلظت هیدروکربن های نفتی خاک های آلوده طی این فرایند مشکل، وقت گیر و هزینه بر است. بنابراین، استفاده از مدلی که به محدودیت های موجود، صورت بندی ریاضی ببخشد و آن ها را رفع کند، بسیار مفید خواهد بود. لذا در این پژوهش، غلظت هیدروکربن های نفتی در ستون خاک طی فرایند گیاه پالایی با استفاده از منطق فازی مدل سازی شد. بدین منظور ستون هایی به ارتفاع 130 سانتی متر از خاک آلوده به ترکیبات نفتی جمع آوری شده از اطراف مخازن نفت پالایشگاه اصفهان، تهیه و بذر دو گونه گیاهی سورگوم و جو در 3 تکرار کشت شد. پس از گذشت 17 هفته، غلظت هیدروکربن های نفتی در اعماق 25، 50، 75 و 100 سانتی متری ستون های خاک تعیین شد. با استفاده از روش منطق فازی با تعریف دو ورودی عمق و زمان و مشخص کردن توابع عضویت و قوانین فازی برای سه تیمار جو، سورگوم و شاهد، غلظت هیدروکربن های نفتی در عمق های گوناگون خاک طی فرایند گیاه پالایی مدل سازی شد. نتایج مدل فازی با مقادیر اندازه گیری شده مطابقت خوبی داشتند. بنابراین، استفاده از روش منطق فازی برای مدل سازی تغییرات غلظت آلاینده ها طی فرایند گیاه پالایی برای سایر مناطق آلوده پیشنهاد می شود.
    کلیدواژگان: آلودگی خاک، آلاینده های نفتی، عمق گسترش آلودگی، مدل سازی فازی
  • علی شهیدی، عباس خاشعی سیوکی، زهرا زراعتکار * صفحات 827-840
    از مهم ترین نگرانی های اخیر در خصوص فاضلاب های صنعتی، ورود فلزات سنگین به منابع آب و محیط زیست است. با توجه به خصوصیات سمی و خطرناک کروم شش ظرفیتی، حذف آن از طریق روش کارآمد و اقتصادی، امری ضروری به نظر می رسد. هدف از این مطالعه بررسی کاربرد پودر ریشه زرشک در حذف کروم شش ظرفیتی از پساب است . پس از آماده سازی جاذب، اثر متغیرهای مختلفی از قبیل pH اولیه محلول، زمان واکنش، وزن جاذب، غلظت اولیه کروم و دما بررسی شد. نتایج نشان داد که کارایی حذف کروم شش ظرفیتی با افزایش pH و غلظت اولیه کروم کاهش، در صورتی که با افزایش مقدار جاذب و مدت زمان تماس ذرات جاذب با محلول حاوی یون کروم، درصد حذف افزایش یافته است که در مدت زمان 90 دقیقه به حالت تعادل می رسد. حداکثر میزان ظرفیت جذب پودر ریشه زرشک برابر 92/23 میلی گرم بر گرم و بیشترین بازده جذب برای ریشه زرشک در دمای 50 درجه برابر 85/97 درصد به دست آمد. نتایج مطالعات تعادلی مشخص کرد که فرایند جذب از مدل سینتیکی شبه درجه اول اصلاح شده و مدل ایزوترمی لانگمیر (R2=0.99) پیروی می کند. بنابراین، می توان نتیجه گرفت که ریشه زرشک به منزله یک جاذب زیستی تجزیه پذیر و ارزان قیمت، عملکرد مناسبی برای حذف کروم از محلول های آبی دارد.
    کلیدواژگان: پساب، حذف، ریشه زرشک، کروم، فلزات سنگین
  • سعید اسکندری *، علی ترابیان، غلامرضا نبی بید هندی، مجید بغدادی، بهنوش امین زاده صفحات 841-854
    فیلترهای شنی بخش ضروری فرایند های تصفیه متعارف اند. ذرات سیلیس فیلترهای تند شنی در حذف مواد آلی محلول، پتانسیل کمی دارند. با ایجاد پوششی از نانولوله های کربنی روی ذرات سیلیس، نه تنها می توان مشکلات استفاده از نانولوله های کربنی در حالت دوغابی را برطرف کرد، بلکه می توان پتانسیل فیلتر ها را در حذف مواد آلی محلول افزایش داد. در این تحقیق از روش های فیزیکی و شیمیایی برای پوشش نانولوله کربنی روی سیلیس استفاده شده است. بررسی استحکام پوشش نشان می دهد که برخلاف پیوند فیزیکی، پیوند شیمیایی دارای استحکام قوی بین بستر و پوشش است. عکس های میکروسکوپ الکترونی روبشی از بستر سیلیس نشان می دهد نانولوله های کربنی به صورت غیریکنواختی روی ذرات سیلیس پوشش یافته اند. نتایج جذب نشان می دهد با ایجاد پوشش روی سیلیس، میزان حذف هیومیک اسید ها از 1 درصد سیلیس خام به بیش تر از 70 درصد رسیده است. مطالعات احیا در محیط های قلیایی نشان دهنده شرایط بهینه واجذب در مدت زمان 30 دقیقه و در pH=13 است، به طوری که ظرفیت جذب بعد از 5 سیکل متوالی احیا در مقادیر مناسبی باقی مانده و به حدود 40 میلی گرم به گرم رسیده است.
    کلیدواژگان: سیلیس، فیلتر شنی، مواد آلی، نانو لوله کربنی
  • محمد قالبی زاده، بیتا آیتی * صفحات 855-865
    رنگزاها از آلاینده های متداول موجود در فاضلاب های صنعتی اند. به تازگی فرایند الکتروفنتون به دلیل کاهش میزان مصرف انرژی، قدرت اکسندگی بالا و تولید محصولات جانبی سازگار با محیط زیست به صورت گسترده در حذف رنگزا به کار برده می شود. در این تحقیق فرایند الکتروفنتون در سلولی به حجم مفید 500 میلی لیتر و با کاتدی از جنس گرافیت و آندی از جنس فولاد زنگ نزن برای حذف رنگ از فاضلاب سنتزی انجام شد. اثر دانسیته جریان، نرخ هوادهی، pH و سطح الکترود در فاضلاب سنتزی بررسی شد و بهینه سازی پارامترها براساس کاهش هزینه های مصرفی حذف رنگزا صورت گرفت. نتایج نشان داد که افزایش شدت جریان، هوادهی، سطح الکترود و کاهش pH موجب افزایش بازده حذف رنگزا می شود. شرایط بهینه پارامترهای موثر در فرایند الکترولیز A 6/0=شدت جریان، 5/6=pH، بدون هوادهی، غلظت اولیه رنگزا mg/L100، سطح الکترود cm260 و زمان الکترولیز 210 دقیقه به دست آمد. تحت این شرایط بازده حذف 90 درصدی رنگزا با میزان انرژی مصرفی KWh/ppm28/0 حاصل شد. براساس نتایج، استفاده از الکترودهای مذکور در فرایند الکتروفنتون به دلیل تولید الکتروشیمیایی رادیکال های هیدروکسیل با قدرت اکسندگی بالا می تواند برای تجزیه فاضلاب حاوی رنگزا و آلاینده های مقاوم استفاده شود.
    کلیدواژگان: اسید اورانژ 7، الکتروفنتون، سطح الکترود، فاضلاب، pH
  • سعید طاهری قناد*، علی افروس صفحات 867-878
    در این تحقیق سینتیک حذف سرب با استفاده از روش گیاه پالایی و با گیاهان نی، تیفا و برموداگراس بررسی شد. به این منظور آبیاری با فاضلاب مصنوعی و با سطوح مختلف غلظت 5، 10 و 15 میلی گرم در لیتر انجام شد. نتایج با چهار مدل سینتیک درجه صفر، سینتیک درجه اول، توانی (هیگوچی) و وابسته نمایی برازش شد. نتایج ضریب همبستگی نشان داد که بهترین برازش به ترتیب اولویت با مدل نمایی، هیگوچی، تابع سینتیک درجه اول و تابع سینتیک درجه صفر به دست آمد و مدل نمایی و توانی طی دوره آزمایش از دقت بالاتری برخوردار بودند. این در حالی است که تابع سینتیک درجه اول و درجه صفر در زمان های اولیه و انتهایی آزمایش از دقت لازم برخوردار نبودند. علاوه بر آن، نتایج نشان داد که ضریب ثابت سرعت واکنش برای سه گونه گیاهی مورد مطالعه در محدوده 0014/0 تا 0071/0 بر روز متغیر بود که این مقدار برای گیاه نی از دو گونه دیگر بالاتر بود. بنابراین، شدت کاهش سرب خاک در شرایط کشت نی از سرعت بالاتری نسبت به دو گونه دیگر برخوردار بود.
    کلیدواژگان: حذف سرب، گیاه پالایی، گیاه آبزی، مدل سینتیک
  • مهری شعبانی*، محمدحسین صیادی، محمدرضا رضایی صفحات 879-886
    امروزه استفاده از کشت ریزجلبک ها برای کاهش دی اکسید کربن توجه ویژه ای را در سراسر دنیا به خود جلب کرده است. این آزمایش با استفاده از پرورش استوک خالص ریزجلبک کلرلا وولگاریس در 3 تیمار و 3 تکرار در محیط آب مقطر، آب دریای شبیه سازی شده و آب طبیعی به مدت 8 روز انجام شد. نتایج نشان می دهد که این ریزجلبک بیشترین تولید زیست توده و به دنبال آن بیشترین میزان ترسیب کربن پس از طی 8 روز در آب طبیعی با مقادیر (g/L/d) 068/0 و (g/L/d) 111/0 داشته و نرخ رشد آن (day-1) 131/0 است. مقدار پارامترهای مذکور در آب مقطر به ترتیب برابر (g/L/d) 057/0، (day-1) 15/0 و (g/L/d) 093/0 است. این نتایج بیان می کند که با پرورش این ریزجلبک در آب شهری به رغم شوربودن، می توان گام بزرگی در ترسیب کربن برداشت. نتایج آماری آزمون توکی نشان داد که بین نرخ تولید زیست توده، رشد ویژه و تثبیت کربن اتمسفری، همچنین تعداد سلول ها در تیمارهای مختلف شوری آب اختلاف معنی داری در سطح 5 درصد وجود دارد. بنابراین، شوری آب در میزان رشد و ترسیب کربن ریزجلبک کلرلا وولگاریس تاثیر متفاوتی داشته است.
    کلیدواژگان: آب شور، بیرجند، ترسیب کربن، کلرلا وولگاریس، گازهای گلخانه ای
  • علی وثوق*، محسن سعیدی، راضیه لک صفحات 887-908
    منابع فلزات سنگین موجود در اکوسیستم های آب شیرین از جمله رودخانه ها می تواند منابع طبیعی یا انسان ساخت باشد. در تحقیق حاضر میزان آلودگی فلزات سنگین در رسوبات دانه بندی شده رودخانه سفیدرود بررسی شده است. بدین منظور از رسوبات سطحی پنج ایستگاه در طول رودخانه سفیدرود نمونه برداری شد. سپس، نمونه ها به طور کامل دانه بندی شدند. در ادامه شش اندازه ذرات رسوبات برای انجام آنالیزهای شیمیایی، محاسبه شاخص های آلودگی و آنالیزهای آماری انتخاب شدند. نتایج آنالیز فلزات سنگین نشان داد که با کاهش اندازه ذرات غلظت تعداد فلزات بیشتری از میانگین رسوبات جهانی و پوسته زمین فراتر و برای برخی همانند منگنز افزایش اندازه ذرات همراه افزایش میزان غلظت این گونه فلزات بوده است. نتایج شاخص های درجه آلودگی اصلاح شده و ریسک اکولوژیک نشان داد که رسوبات 63 تا 125 میکرون به ترتیب دارای آلودگی شدید و ریسک اکولوژیک زیادند. همچنین، میزان درجه سمیت فلزات سنگین با کاهش اندازه ذرات افزایش یافت. نتایج آنالیزهای آماری چندمتغیره نیز نشان دهنده تاثیر فعالیت های انسان ساخت در بالابودن غلظت برخی از فلزات از جمله کرومونیکل و منشا طبیعی فلزاتی همانند آهن و منگنز در رسوبات دانه بندی شده بود.
    کلیدواژگان: آنالیز آماری چندمتغیره، شاخص آلودگی، رسوبات دانهبندیشده، فلزات سنگین
  • اکبر باغوند، رحیم نصیرزاده *، محمد علی عبدلی، علی وثوق صفحات 909-921
    تاکستان واقع در جنوب غربی قزوین و ارتفاع 1265 متر از سطح دریاست که بخش زیادی از آب آن از منابع آب زیرزمینی تامین می شود. جهت جریان آب زیرزمینی دشت، از غرب به طرف شرق است، اما در نواحی شمالی به طرف جنوب شرقی و در نواحی جنوب و جنوب غربی نیز به سمت مرکز دشت و در جهت شمال شرقی تغییر مسیر می دهد. با توجه به آنکه لندفیل تاکستان که تمهیدات بهداشتی خاصی برای آن ملحوظ نشده است، امکان نشت و ورود شیرابه به منابع آب های زیرزمینی مجاور وجود دارد، به همین دلیل بررسی و مطالعه تغییرات کیفیت شیمیایی آبخوان متاثر از شیرابه لندفیل دارای اهمیت بسیاری است. نتایج تحقیق، با مقایسه مقادیر پارامترهای کیفی در شیرابه با استاندارد ملی تخلیه به آب های سطحی و چاه های جاذب، بیانگر آن بود که شیرابه لندفیل تاکستان در سال های 1383 و 1393 دارای مقادیری بیش از استاندارد ملی تخلیه بوده است و نباید به سهولت و بدون مدیریت به محیط پیرامون راه یابد. همچنین، مقایسه نتایج آنالیز پارامترهای کیفی آب زیرزمینی محدوده مطالعاتی بیانگر افزایش شایان توجه برخی آلاینده ها به خصوص فلزات سنگین بوده است. دلیل احتمالی این امر می تواند نشت شیرابه به محیط و نفوذ به منابع آب زیرزمینی مجاور لندفیل باشد. علاوه بر آن، میزان غلظت فلزات سرب، کادمیوم و نیکل در نمونه های آب محدوده مطالعاتی در مقایسه با سایر آلاینده های مورد مطالعه بیشترین تجاوز از میزان استانداردهای کیفی ملی و بین المللی را داشت. به طور کلی می توان گفت احتمالا نشت شیرابه سبب تغییر کیفیت منابع آب زیرزمینی مجاور لندفیل تاکستان شده است.
    کلیدواژگان: آب های زیرزمینی، تاکستان، شیرابه، لندفیل، فلزات سنگین
  • حسین نوروزی، اصغر اصغری مقدم*، عطاالله ندیری صفحات 923-942
    به دلیل وجود آنومالی نیترات در آب زیرزمینی دشت ملکان، 27 نمونه از منابع آب زیرزمینی در شهریور سال 1393 جمع آوری و در آزمایشگاه آبشناسی دانشگاه تبریز تجزیه هیدروشیمیایی شد. در مطالعه حاضر روش جنگل تصادفی (RF)، که روشی یادگیری مبتنی بر دسته ای از درخت های تصمیم است، برای ارزیابی آسیب پذیری پیشنهاد شده است. روش RF نسبت به روش های دیگر دارای مزایایی مانند دقت پیش بینی بالا، توانایی زیاد در تعیین متغیرهای مهم در پیش بینی و ماهیت غیرپارامتری است. در این مقاله عملکرد روش RF برای مدل سازی پیش بینی آسیب پذیری ویژه آبخوان دشت ملکان با استفاده از چهار دسته از داده ها شامل مدل A با تمام متغیرها، مدل B با متغیرهای مربوط به خصوصیات آبخوان، مدل C با متغیرهای نیروهای محرک و مدل D با متغیرهای مربوط به روش دراستیک ارزیابی شد. مدل های A و B با کمترین MSE به ترتیب برابر 012/0 و 013/0 و بیشترین AUC به منزله روش های مناسب برای آسیب پذیری آب زیرزمینی به آلودگی نیترات انتخاب شدند و مدل های C و D با داشتن بیشترین MSE به ترتیب برابر با 015/0 و 026/0 و کمترین AUC به منزله روش های نامناسب شناخته شدند. مدل A که دقیق ترین مدل شناخته شد 44 درصد از منطقه را در محدوده آسیب پذیری زیاد شناسایی کرد.
    کلیدواژگان: آب زیرزمینی، آسیب پذیری، جنگل تصادفی، دشت ملکان، نیترات
  • منوچهر طبیبیان، فریده غنی* صفحات 943-964
    در پی رشد شتابان جمعیت و ظهور تحولات جدید شهرنشینی در جهان، راه حل های متفاوت و گاه متناقضی برای توسعه شهرها مطرح شده است. پیامد این راه حل ها را در الگوهای توسعه ای چون پراکنده رویی، توسعه پرشی و... شاهدیم که سبب تحمیل هزینه های زیرساختی، محیط زیستی و... به شهر می شود. این روند توسعه شهری، سبب بازماندن نواحی مرکزی شهرها از جریان توسعه می شود. مطرح شدن رویکردهای جدیدی چون توسعه میان افزا1، توسعه مجدد نواحی مرکزی شهرها را در دستور کار خود قرار می دهد. هدف پژوهش حاضر اندازه گیری ظرفیت توسعه در بافت مرکزی تهران (منطقه 12) است. در پژوهش حاضر پس از معرفی شاخص های توسعه میان افزا نوبت به بررسی آن ها در منطقه 12 می رسد، برای دستیابی به این مهم با استفاده از ابزار سیستم اطلاعات جغرافیایی (جی آی اس)، تهیه لایه شاخص ها و هم پوشانی لایه ها انجام می شود، سپس اولویت بندی نواحی و قطعات مستعد توسعه در بافت مرکزی تهران با استفاده از فرایند تحلیل سلسله مراتبی صورت می گیرد. نتایج بیانگر آن است که هر 6 ناحیه منطقه 12 دارای پتانسیل توسعه براساس شاخص ها و مولفه های معرفی شده اند، که در این میان، نواحی 3 (هسته اولیه شکل گیری تهران)، 4 و 2 دارای بالاترین ظرفیت های توسعه ای در منطقه اند.
    کلیدواژگان: بافت مرکزی شهر، توسعه میان افزا، سنجش ظرفیت توسعه، سیستم اطلاعات جغرافیایی
|
  • Faezeh Torkianfar *, Amir Hossein Sadeghpour, Mahnaz Mirnorozi Pages 721-743
    Introduction
    Kalat Dam and Hydropower Plant, which is in Maroon River Basin, Kohgiluyeh and Boyer-Ahmad Province is situated in the southwest of Iran. In this research, in order to select the optimum alternative to this Project, with due emphasis on the environmental criterions, three alternatives, namely, Kalat, Sarkooh, and Zirna, are investigated. This plan encompasses the objectives of securing reserves, controlling flood, and producing hydro-electric power (HEP), which is currently studied, from the potentials of Maroon River waters. Table 1 illustrates the most critical technical specifications of the considered alternatives.
    Table1: Technical specifications of the considered alternatives to Kalat Dam and Hydropower Plant Project
    Dam Crest Elevation
    (masl) Dam Height
    (m) Reservoir Area
    (ha) Reservoir Volume
    (MCM) Alternative
    830 130 2119 1313 kalat
    1020 180 1339 704 Sarkoh
    1070 170 751 423 Zirna
    Materials And Methods
    The studied area is located in Maroon River basin. The survey of soil erosion in the reservoir shows that the classification of erosion is not significantly intensive in the studied area. Thereby, from the viewpoint of erosion, the alternatives are in a desirable condition.
    In the limits of the dam reservoir in Kalat, Sarkooh, and Zirna options, there are a number of 15, 8, and 2 villages which are located, respectively. Only within the limits of the reservoir of Kalat alternative, there exist two shrines and a historical bridge, which shall be submerged during the water-intake of the reservoir.
    To determine the ecological capacity of reservoirs, slope, bedrock permeability, and density of vegetation, cover maps are used. Ecological model is classified into three groups: suitable, semi-suitable, and unsuitable. After overlaying the maps, the ecological capacity of the region is prepared.
    In order to determine the optimum alternative, the analytic hierarchy process is utilized. The first step in this method is to create a structural formation at three levels, which are: Level 1-
    Objective
    in selecting the optimum alternative, Level 2- Factors: in the way of criterions, and Level 3- Plans: considered for the selection.
    To determine the criteria, check-list method is utilized. Subsequently, in accordance with the results of the check-list, the primary criteria are determined. In this research, by taking the environmental observations into account, 9 key criteria are selected.
    In the second step, their weighting or coefficient importance is determined. To evaluate a criterion in relation to another criterion, a numerical value of 1 to 9 is taken into consideration such that two criteria, which are of an equal value, are evaluated numerically as (1). However, if the importance and priority in applying a criterion are infinitely more than those of another criterion, its comparative evaluation is considered 9 and the intermediate digits are determined based on the relative importance of the criteria.
    In the third step, on the basis of the implication of the criterion coefficients and utilization of Expert Choice (EC) software, the weighting or significance of each of the indexes, relative to those of a higher level (relative weight), are computed. Such comparison and weighting are implemented in pairs between the criteria.
    In the fourth step, the alternatives are separately compared in the form of pairs in each criterion and are weighed. However, in the ultimate step, by combining the comparative weightings of the alternatives and criteria, the final weighting of each alternative is calculated. Finally, the alternative that gains the optimum weight shall bear a critical degree of importance with respect to the other alternatives.
    Discussion of
    Results
    According to the results of assessment shown in Figure 1, ecological capacity map shows that 100% of Zirna alternative and more than 91% of Sarkoh and Kalat alternatives are located in suitable and semi-suitable zones. Because of different criteria, in order to determine the optimum alternative, multiple criteria decision analysis is utilized.
    Fig.1: Ecological capacity map of three alternatives
    In accordance with the basic studies and environmental conditions existing in the studied area, the environmental consequences of the plan are investigated in order to determine the environmental criteria (indices) using check-list method.
    Based on the results obtained from the predicted impacts in Kalat, Sarkooh, and Zirna alternatives, it can be concluded that, despite the high importance of some criteria, they are not selected for determining selected criteria, since all the three alternatives have the same or similar conditions. Therefore, the most critical environmental criteria selected from the check-list method are: land use, threatened species of index flora having ecological value, index fauna, rural population centers, limits of the operational area influenced from the viewpoint of environmental destruction, land ownership, cultural heritage sites, other development plans and seismicity of sites.
    In the subsequent phase, by utilizing Expert Choice software, the weighting of the criteria with respect to each other is mutually performed in such a manner that an increment in points, from 1 to 9, illustrates a more critical value in one criterion compared to another. In considering all the aspects and criteria, the alternative relative to Zirna, which has attained the highest points of 0.347, is the selected option, whereas the alternatives of Kalat and Sarkooh with the ranking of 0.339 and 0.314 points, respectively, are the second and third priorities. The results of comparison and points of the three alternatives demonstrate that the alternative of Sarkooh which has a noteworthy variation relative to the other two options has minimum points. The results attained in the developed model in the ‘Expert Choice software is demonstrated in Figure 2.Fig. 2: Results of the final weighting of the alternatives in the ‘Expert Choice’ Software
    Conclusion
    Results obtained from this research illustrated that, in order to determine a choice of alternatives from the environmental point of view, conditions relating to land use, index flora, seismic conditions, and regional population specifications are of greater importance. Hence, they had an immense impact on determining the ultimate site. Comparison of the final points, which were determined for the three axes, showed that the sites of Zirna, Kalat, and Sarkooh, which attained 0.347, 0.338, and 0.312 points, respectively, gained the first to third priorities in terms of being selected for the dam location.
    In the preliminary survey and without specifying the significant coefficients of the criteria, it seemed that, due to a few distinctions such as presence of accessible roads and less amount of damage to the reservoir, Sarkooh alternative gained the first preference for the dam construction, since, with the disclosure of all the major criteria in decision-making and bringing into consideration the critical coefficients as well as coupling comparison between the alternatives, it was specified that this alternative would be at farther distance than other options, ranking the last priority. Thereby, in all the projects in which a selection should be made between several alternatives which are subjected to numerous factors, it is essential to utilize appropriate multiple criterion assessment methods.
    Finally, it is proposed that, since numerous dam and power plant projects are simultaneously studies or implemented in this basin, in order to prevent biased attitudes toward a specific project, strategic environmental assessment studies and regional planning must be performed.
    Keywords: environmental impacts, Check, List, Multiple Criteria Decision making, optimum alternative, Prioritization
  • Farnaz Sheybanifar, Mir Mehrdad Mirsanjari* Pages 745-755
    Introduction
    Environmental pollution, especially marine pollution, is one of the complex and minatory problems that human is facing at the present time. Many of human activities have irrecoverable outcomes and affect the marine environment in such a way that destruction of marine zones has become a significant warning. One of the most important ecosystems in Iran is Hara biosphere reserve, located in the southern part of the country, and in the northwest of Qeshm Island in the protected zone of Hara. Since it is situated near the city of Bandar Abbas (the largest southern port of Iran in the Persian Gulf) and because ofits location at the margins of the northern coast of Qeshm Island (the largest island and commercial-industrial free zone of the country in the Persian Gulf), this region has been subjectedto urban and industrial pollutions. One of the most important pollutant sources, which has jeopardized the life of this ecosystem with serious threats in the recent decade, is the entry of heavy metals from various pollutant sources. Heavy metals are the most important contaminants that enter into the sea through rivers and shore zones and aggregate in the aquatic body through the food chain.
    Most of these elements are not necessary for animals but have high toxic properties. One of the most imperative problems about heavy metals refers to their insoluble characteristic in the body. Indeed, heavy metals never excrete from the body, but they sediment in fat, muscles, bones, and joint tissues and may cause illnesses and various other phenomena. Birds, in comparison with other animals, are much more sensitive to environmental pollution. They may distribute chemicals, such as heavy metals, through direct connection or using polluted water or food. In other way, because of their indirect connection to polluted sources, they can determine the level of toxic element concentration in the marine ecosystem food chain. Therefore, the birds’ pollution of heavy metals can be used to anticipate the pollution level in the food chains. Among different tissues, mostly the soft tissues of birdsareused for the monitoring operation.
    In many studies, the tissues of muscle, liver, kidney, spleen, heart, lungs, fat, blood, brain, and bone, and in some others, the feather and egg have been used toinvestigate the concentration of heavy metals in the environment. The selection criteria for choosing the suitable bird species (generally the suitable environmental monitors) include: sedentary species, proper distribution, easy identification, long life, availability during the whole year, carnivorous species, stability against fluctuations, and physiochemical features.
    The birds that have most of these characteristics are not numerous. In fact, the maximum reflection of the heavy metals ratio is the purpose of these limitations and therefore, according to the above conditions, Great Cormorant (Phalacrocorax carbo) was selected as a suitable species to evaluate the heavy metals concentration. Great Cormorant is a species dependent on the aquatic ecosystem with a plentiful population and a wide distribution. In addition, its special piscivorous behavior has been always attractive for researchers.
    The purpose of the present study is to compare the concentration of heavy metals (i.e. nickel, cadmium and lead) in the kideny, muscle and liver of the great cormorant between the male and female cormorants, and also to compare the concentration of heavy metals between the mature and immature cormorants.
    Materials And Methods
    Hara Biosphere Reserve is located in the south of Iran in the Strait of Khuran, between Qeshm Island and the mainland of Iran, in the Persian Gulf, and with 86,581 hectares area. Its latitude and longitude coordinates are 36°40' to 37° and 55°21' to 55°52' E, respectively. It is situated in the Mehran River delta and hosts the largest seabirds along the Persian Gulf shoreline and, therefore, it would represent a center of biodiversity in Iran. The variety in this biosphere reserve and its unique mangrove trees provides a diverse habitat for birds like egrets, herons, pelicans, and plovers. Based on the available statistics, in 2010, the biosphere reserve had been the host of 36 species and 13,000 water birds and wader birds. Hara also serves as a breeding and spawning habitat for fishes, shrimps, and other crustaceans.
    After primary studies about the studied areas, we collected 12 Great Cormorant samples in November and December 2012 from Hara biosphere reverse.
    After collection, we separated kideny, muscle and liver then, placed in the oven at 65 °C for 24 hours. In the digestion phase, 8 ml of nitric acid (65%) and 2 ml of perchloric acid (60%) (i.e. at the ratio of 4:1) were added to each sample (1 gram of the weighted sample). In a hot-block digester, they were digested firstly at 40 °C for 1 hour and then, at 140 °C for 3 hours. Afterwards, samples were screened by Whatman paper No. 1 and the solution’s volume reached 25 ml by using distilled water. At the end, all samples were kept in the refrigerator in polyethylene jars in order to later evaluate heavy metals concentration by atomic absorption machine.
    In order to ensure about accuracy of the digestion process, in each digestion round, there was a control sample to subtract the sizable results from concentration of the metal in different samples. In this study, measurement of heavy metals concentration was performed by atomic absorption machine (model contrAA 700).
    Discussion of
    Results
    The results revealed that The maximum and average concentrations belonged to lead and the minimum related to nickel. Also the results indicated that the average of heavy metals were highest in kideny and lowest in muscle.
    In this study, the high lead concentration in some of the samples from Hara biosphere reserve demonstrated this fact that the birds’ environment is under extreme pressure due to existence of lead.
    Lead is a contaminant, which can be found everywhere and enters into the sea through various industrial wastes from the printing industry, oil refinery, etc. Human activities, along with the developments of the oil refinery and petrochemical plants, added to zinc and lead factories in Qeshm, and marine transportation in the south of Iran, may play the most important roles in absorption of this metal in the tissues of this bird.
    The existence of heavy metals in the tissues of the great cormorant in Hara biosphere reserve can be due to the presence of oil refineries and usage of petrol nearby the studied area.
    Burger and Gochfeld (2000) indicated that the undesirable effects of lead in birds occurs atthe concentration of 4000 ppb, althoughaquatic birds are able to tolerate even the concentrations higher than this level. If the lead concentration in birds’ tissues reaches over 4000 ppb, it would bring some problems, such as the decrease in the bird’s perception, decrease of chickens’ survival, inability in recognizing the sibling species, and the behavioral and nutritional problems. The behavioral problems of birds resulting from cadmium occur at the concentrations much lower than the lead and mercuryconcentrations.
    In this research, the T-test results were used for comparing the concentration differences between two genders and it was shown that there is a significant difference among nickel and lead concentrations in three tissues of males and females (P
    Conclusions
    The results revealed that The maximum and average concentrations belonged to lead and the minimum related to nickel. Also the results indicated that the average of heavy metals were highest in kideny and lowest in muscle. The results revealed that age factor affected on cadmium and nickel accumulation and sex affected on nickel an lead accumulation in all of Great Cormorant´s tissues. Heavy metals levels are below the range to cause behavioral change or reduce reproduction.
    Keywords: Great Cormorant, Heavy metals, Hara Biosphere Reserve
  • Nateq Lashgari, Jamshid Ghorbani *, Seyed Hassan Zali, Ghorban Vahabzadeh Pages 757-770
    Introduction
    Mining is traditionally regarded as the world’s oldest and the most important activity after agriculture. Despite being an important economic activity, mining causes substantial damage to the environment worldwide. The environmental impact of mining includes erosion, formation of sinkholes, dust, noise and water pollution, vegetation degradation, loss of local biodiversity, and contamination of soil, groundwater, and surface water by chemicals from mining processes. Mine reclamation is the process of restoring land that has been mined to a natural or economically usable state. Establishment of a vegetation cover is essential to stabilize the bare area and to minimize the pollution problem. Mine restoration can aid in maintaining native wildlife populations while providing other valuable ecosystem services, such as erosion control, carbon sequestration, wood production, water-quality improvement, and watershed protection. Area under mining are often characterized by high bulk density, low pH, low nutrient availability, poor structure, low water holding capacity, and low biomass productivity. Basically, there are two approaches to reclamation or restoration of a disturbed site: (1) allowing spontaneous succession or (2) using technical reclamation with sowing or planting target species, accompanied by restoration or improvement of site conditions. There is also a third approach when spontaneous (natural) succession is reasonably directed with the aim to reach a target community. However, until now most restoration projects have relied on technical measures more than on spontaneous natural processes. Main technical methods include the use of mycorrhiza, remediation, fly ash, hydroseeding, top soil, and compost.
    The main aim of mine restoration is the permanent establishment of vegetation and soil quality improvement in order to increase the ecosystem function. In the first step it is very important to identify the early successional species which can colonize on coal wastes. Spoil heaps after coal mining are an important component of the landscape in several parts of Alborz mountains, where lignite coal is mined deeply or in open-cast mining. Therefore, we studied the potential of plant establishment on spoil heaps and compared the natural vegetation recovery on these heaps with nearby rangelands.
    Materials And Methods
    This study was carried out in Karmozd area in Savadkoh county, Mazandaran provice (52º57'38" to 52º58'12" E and 36º05'57" to 36º06'53" N). This area has been one of the most important mining areas in central Alborz mountains. The climate of the area is cold humid (536.5 mm annual rainfall, 10.9 ◦C annual average temperature). Three spoil heaps were selected regarding age and the amount of spoil. Spoil heap 1 was the oldest and biggest one while spoil heap 3 was the youngest. Vegetation was samples in all three heaps and the rangeland nearby. Sampling was done along transects using 138 plots of 1 m2. The cover (%) of each species was estimated in each plot. Data were transformed using ASIN(SQRT(x/100)) and then a combination of analysis of variance and t-test were performed for individual species response. Also, we compared the species diversity and richness indices among these sites.
    Results And Discussion
    A total of 43 species from 20 families were identified in study area. Gramineae, Asteraceae and Lamiaceae were the most common plants. About 60% of species were perennials. In spoil heap 1 there were 35 species of which 22 species were unique (Table 1). Greater number of annuals and prennials were found in spoil heap 1. It seems that the seeds of 22 unique species were dispersed from surrounding area to spoil heap 1. The germination and establishment of new arrived seeds in spoil heap 1 is possible as this spoil heap is in the vicinity of river and also it had been longer existed than other heaps. The pioneer species in spoil heap 1 are those reported in other studies worldwide. There were 10 species common between spoil heaps and nearby rangelands. Alyssum linifolium, Artemisia scoparia, Bromus briziformis, Colutea persica, ¡Hordeum vulgare and Rumex acetosella were found only in spoil heap 1 and spoil heap 2. Artemisia scoparia was the dominant species in rangeland. In spoil heap 1 the dominant species were Hordeum vulgare¡Glaucium fimbrilligerum and Artemisia scoparia. The common species in spoil heap 2 were Glaucium fimbrilligerum, Melica persica and Artemisia scoparia while Kochia prostrata was the main dominant species in spoil heap 3. Greater EC was found in soil heap 3 and this is the main reason for the establishment of K. prostrata.
    Spoil heap 3 significantly had the least species richness and diversity (Fig. 1). There was no significant differences among spoil heap 1, spoil heap 2 and rangeland regarding species diversity while species richness was significantly greater in rangeland than that in spoil heap 1 and spoil heap 2. The greater values of species richness and diversity indices were expected for rangeland as it has a thin layer of developed soil. The soil heap 3 is the youngest coal waste, so this can be the main reason for having less species richness and diversity indices.
    The harsh environmental situation made this heap only suitable for K. prostrata establishment. Artemisia scoparia, Bromus briziformis and Stachys laxa significantly showed greater cover values in rangeland than that in spoil heaps. In contrast, greater cover (%) of Melica persica and Hordeum vulgare were found significantly in spoil heaps than that in rangeland. The greatest cover (%) of annuals was found in soil heap 1 and 2 while spoil heap 3 had the least cover (%) of annuals. The maximum and minimum cover (%) of perennials was found in rangeland and spoil heap 3, respectively.
    Conclusion
    Native species are recommended for long-term restoration of mine wastes as they have more potential for establishment. The establishment of early successional species is related to their seed dispersal from surrounding area. Thereafter, their potential for producing persistent seed bank is very important. The results of this study showed that there is a potential of early successional species to establish on coal wastes. The amount of natural colonization was different among spoil heaps and we found this was related to spoil heap area and age after abandonment.
    Keywords: Coal mine waste, Vegetation succession, Species richness, diversity, Pioneer species
  • Mohammad Panahandeh *, Habib Fathidokht Pages 771-781
    Introduction
    Landscape structure means the pattern of a landscape, which is determined by its type of use, but also by its structure, i.e. the size, shape, arrangement and distribution of individual landscape elements. For the delineation of these landscape elements, or so-called patches, often land use or land cover units are used. In this context, “‘land cover’ refers to the physical surface characteristics of land (for example, the vegetation found there or the presence of built structures), while land use describes the economic and social functions of that land. The heterogeneity of landscapes – as a parameter of landscape structure – is connoted as the quality or state of consisting of dissimilar elements, as with mixed habitats or cover types occurring on a landscape. It is the “opposite of homogeneity, in which elements are the same. As indices of landscape structure, landscape metrics can be used to describe the composition and spatial arrangement of a landscape. They can be applied at different levels to describe single landscape elements by such features as size, shape, number or for whole landscapes by describing the arrangement of landscape elements and the diversity of landscape. The reason for using these metrics in spatial analysis may be to record the structure of a landscape quantitatively on the basis of area, shape, edge lines, diversity and topology-descriptive mathematical ratios; to document for purposes of monitoring; or to make the relevant information available as input parameters for landscape ecological simulation models.
    Biological diversity in all its dimensions and facets is always tied to habitats, which need a concrete areal section of the earth’s surface for their existence. Biological diversity is therefore always defined for a certain reference area, and landscape structure is a key element for the understanding of species diversity. Spatial heterogeneity, as an expression of landscape structure, indicates the variability of the system’s properties in spatial terms. Since the complexity of biological diversity is difficult to describe, most ecologists have taken the practical way to research and to identify the biological diversity at the species level Therefore, the selection of structural indicators was undertaken specific to the habitat type or tested species studied. Local data on species diversity can provide information as a proxy for regional biodiversity. An investigation of flora and fauna is, however, typically not comprehensive, but rather generally covers only a small proportion of all species. The clear determination of the diversity of various taxonomic groups requires very high efforts, knowledge and money. Hence a good substitute is needed. By combination of indicator species and groups with spatial environmental data and landscape structure, the power and deputy information can be increased and expanded geographically. Which parameters are suitable for the characterization and description of landscape diversity, and can therefore be used as an indicator for biodiversity? In principle, a few indicators are sufficient to ascertain landscape patterns. However, biodiversity cannot be described only by a simple number, as there are various qualities of spatial patterns . A selection of indices representing various aspects of biodiversity is much more informative and capable of interpretation . However, the use of many highly correlated indices provides no new information, and leads to problems in interpreting the results. For this reason, mutually independent indices should be selected .By means of indicators in monitoring, dramatic changes in values can be detected and serve as an early warning, and as an indication of the necessity for deeper investigation, even if no specific limit values can be defined . Landscape metrics may also be used to identify hot spots of biodiversity. Although they do not replace direct measurement of species biodiversity, these surveys can help make them more effective and less.
    Habitat fragmentation also reduces the productivity of ecosystems because smaller areas of habitat are often less resilient to severe weather or disease shocks.
    Habitat fragmentation is often a cause of species becoming threatened or endangered. The existence of viable habitat is critical to the survival of any species, and in many cases the fragmentation of any remaining habitat can lead to difficult decisions for conservation biologists. Given a limited amount of resources available for conservation it is preferable to protect the existing isolated patches of habitat . The design of efficient and effective land conservation policies must therefore consider both the total amounts of habitat conserved and the spatial configuration of that habitat.
    Forest fragmentation has become a global concern for conservation of important habitats as well as biodiversity. Protected areas that have been a cornerstone for safeguarding biological diversity are also facing enormous stress due to the increasing anthropogenic activities.
    The impacts that fragmentation has on both wildlife and vegetation within a fragment and perhaps more importantly, the impact of loss of intact habitat and wildlife on the people relying on the remaining fragments, are important to understanding and slowing or preventing future decline. As fragments decrease and become more degraded, encroachment into the park and the number and severity of human-wildlife incidences may increas.
    Establishing protectd ara is the primary mechanism used to protect forest biodiversity, particularly in regions with high human densities. protected areas protect and maintain endemic, threatened or endangered, flora and fauna, geological features, and cultural heritage sites. In addition, they can generate income for the local and national economies, and provide important benefits associated with enhanced tourism sectors. However, many protected are also associated with negative social and ecological impacts. The processes that drive land cover change are complex and cannot be understood without addressing underlying cause and effect relationships. Changes in climate, population, and land use occur and interact simultaneously at different temporal and spatial scales, having major implications for both livelihoods and biodiversity. Forest loss and fragmentation are regarded as the greatest threat to global biological diversity.
    This study estimates the degree of spatial fragmentation in the protected area. Landsat TM 30 m satellite images of 1988 and 2014 were used as base maps in this study.
    The purpose of this study was to determine the extent and direction of changes in dense vegetation cover of Anzali watershed with using landscape ecology approach during period of1989-2014.
    Material and
    Methods
    As indices of landscape structure, landscape metrics can be used to describe the composition and spatial arrangement of a landscape. They can be applied at different levels to describe single landscape elements by such features as size, shape, number or for whole landscapes by describing the arrangement of landscape elements and the diversity of landscape. The purpose of this study was to determine the extent and direction of changes in dense vegetation cover of Anzali watershed with using landscape ecology approach during period of1989-2014.This area has been selected for its habitat values and its role in sustainability of international watershed of Anzali. First Anzali watershed area extracted then dense vegetative cover area extracted from it. This area was classified in two classes of vegetation cover and bare. In following after separating Gashtrodkhan protected area ,its dense vegetation cover was interpreted. After that vector layers of vegetation cover were built that it was used as input of patch analyst extension to calculate metrics.
    Discussion of results and
    Conclusions
    The results present considerable changes in CA,Numps,Mps,ED and TE metrics both in all patches and main patch that with respecting the direction of change it can be concluded fragmentation process is rising.
    Keywords: Landscape, metrics, Anzali Wetland, Fragmentation
  • Rashid Saeedabadi, Shoaieb Abkharabat, Mohammad Saeed Najafi Pages 783-798
    Introduction
    Many aspect strongly influence regional climate includes localized surface processes, large-scale patterns, especially mid and upper level tropospheric circulation and many factors control precipitation in the west of Iran includes location of emigrate westerly winds systems, Jet streams location, Humidity Flux and topography. Upper tropospheric jet stream constitutes a significant factor influencing physical processes, includes ascend or descend movements in the lower atmosphere in both synoptical and climatological time scales. Polar jet stream and subtropical jet stream are two main Upper tropospheric jet streams affects climatology mid latitude atmosphere. In this regard, formation of polar jet stream is related to thermal contrast in the polar front because of its proximity to the ground has greater role in providing ascendant atmospheric condition and precipitation. But sub-tropical jet stream locate at upper atmospheric level in tropopause and such condition can’t have a prominent role as polar jet stream in ascendant condition, especially in precipitation. In addition because the subtropical jet stream does not have other factors in polar jet stream such as polar front, dynamic properties of this does not have affect climate feature of earth surface. Typically Jet stream potential can affect divergence and convergence, develop and steer the pressure systems (Farajzadeh et al., 2008) and change control the weather patterns and climate. The Polar jet stream is one of main factors that affect climatology if western Iran in winter.
    In addition to jet stream location, the atmospheric moisture budget plays an important role in precipitation and hydrology. Existence of polar jet stream the companied with adequate moisture can lead to heavy rainfall in each region. The objectives of the present study are understand the location of polar Jest Stream during the heavy rains in Western Iran and characteristics of moisture flux from each region of moisture source and their contribution to the rainfall during the mentioned period.
    Material and
    Methods
    This study focus on western Iran, that extends between the latitudes 33° N and 36° N and the longitudes 46° E and 48° E (Fig 1).
    1. The study area For determine the days with heavy rainfall the Mofidi et al (2007) method have been used. Hence the heavy rainfall was the amount of rainfall during the day with equal to or greater than 5% of the average annual precipitation and also over 50 percent of western Iran must receive heavy rainfall. So the 48 days with heavy rainfall for current study have been extracted. The location of PJS were analyzed according to atmospheric circulation types in 75 days with heavy rainfall using daily mean of the 500 hPa geopotential height data for these days between 10°–80°E, 10°–60°N, with a 2.5° (lat) × 2.5° (lon) spatial resolution that’s includes 609 grids. So a 48 × 609 matrix was created. For determine the atmospheric circulation types and location of PJS during heavy rainfall over western Iran an agglomerative hierarchical cluster analysis was applied to the 48×609 matrix using the ward algorithm with Euclidean distance to identify atmospheric circulation types. Then calculated the within-group correlation to identify representative days. In continues, the convergence and divergence of moisture flux from two days prior to representative days was investigated. The convergence and divergence of moisture flux was calculated in 1000 hPa to 500 hPa levels for determine the main source of moisture flux in various atmospheric circulation types and arrangement of polar jet stream in time of heavy rainfall in western Iran. For this purpose, four daily NCEP/NCAR reanalysis data includes specific humidity, zonal and meridional wind speed components (U; V components) for 1000 to 500 hPa have been used.
    Results And Discussion
    According to results of hierarchical cluster analysis, 4 groups of atmospheric circulation types affecting the location of polar jet stream in both level of 300 and 500 hPa, associated with heavy rainfall in western Iran was detected. Usually the annual rainfall in western Iran are associated with location of polar jet stream and emigrated systems of westerly winds. In pattern 1, the heaviest rainfall occurred at 00Z. Formation of deep trough in westerly winds on the East Mediterranean, lead to the formation of cut-of-low in both of 500 and 300 hPa levels. Existence of this trough in company with polar jet stream lead to intensification of the unstable condition in the atmosphere of western Iran. So that in both level of 300 and 500 hPa, the west of Iran is located in the second quarter zone of polar jet stream. In this pattern the polar jet stream core in the west of Iran has taken a meridian curve and this issue provides more favorable conditions for convection and ascendant condition in atmosphere. In this pattern the main sources of moisture are West Arabian Sea, Persian Gulf, Red Sea and East Mediterranean is the secondary source that is less important.
    In the second pattern, formation of a deep trough on the Red Sea convergence zone provides more favorable conditions for ascendant condition in the west of Iran. The location of polar jet stream in this pattern is in lower latitude in comparison with first pattern and intensify of polar jet stream is less than previous pattern. The main sources of moisture in second pattern are Arabian Sea and Red Sea and also Persian Gulf and Oman Sea are secondary sources for this pattern.
    In the third pattern, the expanding of trough in waves of westerly winds was wide, from the Mediterranean Sea to the West of Iran. This issue, decrees of deep and increase of expansion in westerly wind waves, cause decrease in intensify of unstable condition in atmosphere of western Iran. Expansion the core of polar jet stream from east of Africa to west of Iran that located in the second quarter zone of polar jet stream has caused increase of unstable condition in this region. The main sources of moisture in this pattern are Arabian Sea, Gulf of Aden, Red Sea Persian Gulf and Oman Sea. In the fourth pattern, existence of a deep trough on westerly wind waves over the Red Sea lead to increase in intensity of polar jet stream that located in Middle East. So, this condition caused increase of unstable atmospheric condition in western Iran and according to moisture flux lad to heavy rainfall in this region. The main sources of moisture in this pattern are Arabian Sea, Gulf of Aden, Persian Gulf and Oman Sea.
    Conclusion
    Results of this study show that in all atmospheric circulation type that lead to heavy rainfall in western Iran, this region was located under the second quarter zone of polar jet stream. Therefore this condition provides more favorable conditions for convection and ascendant condition in atmosphere. And also the main sources of moisture in heavy rainfall cases were Arabian Sea, Gulf of Aden, Read Sea, Persian Gulf and Oman Sea.
    Keywords: Polar Jet Stream, Moisture Flux, Heavy Rainfall, Synoptic, West of Iran
  • Aliakbar Shamsipour *, Elham Ashrafi, Marziyeh Alikhah Asl, Khosro Ashrafi Pages 799-814
    Introduction
    Air pollution is the introduction of particulates, biological molecules, or other harmful materials into the Earth's atmosphere, possibly causing disease, death to humans, damage to other living organisms such as food crops, or the natural or built environment. The atmosphere is a complex natural gaseous system that is essential to support life on planet Earth. Stratospheric ozone depletion due to air pollution has been recognized as a threat to human health as well as to the Earth's ecosystems. The cement industry has 79 years record in Iran and with total cement annual production capacity of 66 million tons; is the largest cement producer country in the Middle East. In the various stages of production process of the material many pollutants is released into the environment. Cement industry has always been associated with air pollution. From types of pollutants Releases, particulate matter is the most important pollutants of cement plants. In recent years, the cement plant located in the south of Tehran, is one of the most polluting industries in our country and is numbered one of the most important cause of air pollution in the region.
    Material and
    Methodology
    From the first steps for the control and reduction of air pollutants emissions, is specified and detected their distribution. Air emissions modeling studies, provide possibility to get useful information for strategies implementation for air pollution controlling in the future. Pollutants dispersion modeling in a variety of emission sources, weather conditions, and pollution source location maybe capable to provide the desired output for the planning and management of reduction and control the emissions pollutants. Air quality models are widely used in recent several decades and made based on calculations by the computer.
    Computer modeling of air pollution dispersion model was used by AERMOD. AERMOD is a steady dispersion state model and for determination the concentration of different pollutants in urban and rural areas, smooth and rough, and the high level of emissions from point sources, the volume and variety of surface materials can be used. The model images distribute and dispersion of pollutants from the source to the receiver. So in this studying, model was used to simulate the particle dispersion and was used to evaluate the emission effects of various industrial sources, The model is applied for evaluating the emission effects from various industrial sources at distances less than 50 km and has been investigated zoning the radius of dispersion of pollutants. AERMOD model uses two preprocessor. AERMET is a meteorological preprocessor and another named AERMAP which is a geologist preprocessor. AERMET preprocessor processes meteorological data and estimates atmospheric boundary layer parameters for use in the model and AERMAP preprocessor analyzes the regional topographic information.
    Figure 1. Data preparation process in AERMOD by preprocessing of AREMET
    Finally the model using result of these two processors and supplemental information about the sources of emission and acceptor networks done the calculations and presents final results.
    Figure 2. General stracture of AERMOD model
    Results And Discussion
    In this study, The basic data considering measurement reports and output aerosol sampling of the stack and weather data from the meteorological organization (In this research was used climate variables such: temperature, relative humidity, wind direction and intensity, in daily scale for Doshan-tappe weather station on 2010) And the studied plant was obtained . In the next step the pollutants sources location map separately was prepared the resolution in the factory location(onsite) and nearest weather station. Then Distribution of particulate emissions for time average of 1, 3, 8 and 24 hours And a period of one month and seasonal for both summer and winter conditions by entering the data related to each stack AERMOD model with Emission rate in grams per second by calculating the flow on the scale of Micrograms to the seconds and multiply by that values for each output aerosol concentration in micrograms per cubic meter, were done.as a matter of fact emissions variables and pollutants properties (chimney height, speed and exhaust gas temperature, the volume of pollutants, etc.) of the cement plant, according to a quarterly sample results were received from 12 sources of pollutants that were all kinds of chimneys. Finding of air pollution dispersion modeling shows that the greatest impact of suspended particles at a distance of 1 to 5 km from the emission source occurs. Particles in the summer entry to Tehran from the plant origin had increased further, and covered to 15km of the source.
    in this study, simulation was done for 2 meters height or surface to breathe. Simulated altitude is assumed in a flat mode.by referencing to the results of modeling, in both summer and winter periods, for the hourly average are highest value. In both hourly cases the prevailing point is emission source Eastward. In the summer case, due to heat and the more intensity wind blowing, the more range of area around the plant is located within the dispersion of pollutants. Dominant point of factory pollutants spread is South East and East. The concentration because of the high density of suspensor solid Particles than air, decreases more rapidly with increasing distance from the stack. After a long gap, pollutants dispersion to surrounding is caused to reduce its concentration. As it is known, the concentration minimum respectively was recorded at monthly and seasonal averages and particle volume maximum is occurred in hourly average especially on the one-hour. So in the meantime, a considerable difference was seen in levels of particulate pollutant concentrations.
    Conclusion
    So considering the concentration of particles Standard in Iran and EPA, is observed that result for the Model output is multiplier than Standard rate. And in the hourly and daily measures in the vicinity of the emission source and a factory space, particle size is high.It is proposed cement plant use hybrid filters in their product lines due to significantly reducing its dust.
    Keywords: Cement plant, Particulate matters, Air pollution modeling, AERMOD
  • Farida Irajy Asiabady *, Seyed Ahmad Mirbagheri, Ali Asghar Besalatpour Pages 815-825
    Introduction
    Isfahan Oil Refinery (Isfahan, Iran) is responsible for the production of huge amounts of oil waste. As the released organic compounds are highly toxic, carcinogenic, and mutagenic, they can potentially contaminate the soil and groundwater resources of the adjacent area. This is particularly important in Isfahan where arid/semi-arid climate has limited the access to adequate surface water resources. Among the various methods proposed for oil-contaminated soil remediation, phytoremediation has been identified as an efficient and cost-effective technique. Limited access to soil samples from various depths during phytoremediation along with the cost, time, and effort required for quantitative measurement of TPH necessitates the development of a mathematical model to overcome the existing obstacles. Fuzzy logic is a feasible method for modeling systems with inadequate or vague and non-specific information. The fuzzy set theory, introduced by Zadeh in 1965, allows the user to define the rules and understand the relations between parameters and the existing decision-making process. Consequent to its constant evolution, the fuzzy set theory has found various applications. While fuzzy logic techniques have not been as extensively applied in the environmental field as in other fields such as industrial control systems, their diversity and progression increase their potential to affect environmental policymaking.
    Therefore, in recent years, numerous studies have evaluated the application of fuzzy logic methods to assess air quality and pollution, quality of surface waters, health of the rivers, groundwater contamination, and river water quality classification has also been investigated. In Iran, however, fuzzy logic has not been commonly practiced due to the unfamiliarity of environmental experts with the subject. The present study applied fuzzy logic to model TPH concentrations at different depths of soil during phytoremediation. Considering the inaccessibility of all soil depths, high costs of measurement, and the existing ambiguities, such a model will facilitate the evaluation and control of soil contamination.
    Method
    2.1. Determining physical and chemical properties of soil
    Soil samples were collected from the contaminated lands contiguous to Isfahan Oil Refinery’s Sulfur Recovery Unit where oil waste was accumulated. The samples were air dried and ground to pass a 2-mm sieve. Soil structure, electrical conductivity, pH, organic matter, available potassium and phosphorus, cation exchange capacity (CEC), total nitrogen, the concentrations of TPH and polycyclic aromatic hydrocarbons (PAH) were measured according to standard methods.
    2.2. Phytoremediation experiment
    Phytoremediation experiments were conducted in 130-cm long polyvinylchloride pipes (width: 20 cm) with 20-cm sand filters on the bottom. The pipes had holes at 25, 50, 75, and 100 cm depths to make the final sampling possible. The prepared soil columns were planted with either sorghum or barley seeds or left unplanted. In order to assess the resistance and stability of the plants in contaminated soil, they were maintained for 17 weeks after seeding. TPH concentrations at 25, 50, 75, and 100 cm depths of all soil columns were measured 120 days after seeding.
    2.3. Fuzzy modeling
    Data modeling with fuzzy logic was performed in three phases using MATLAB.
    2.3.1. Fuzzification of the inputs and the output
    The inputs and the output were defined using linguistic variables and membership functions (MF). Depth was defined with four linguistic variables, i.e. very low (0-25 cm), low (25-50 cm), average (50-75 cm), and high (75-100 cm). Time was also defined through two linguistic variables, namely short (0-20 days) and long (20-120 days). The output (TPH concentration) was defined with four linguistic variables including low, average, high, and very high. While the Gaussian MF was applied on depth and TPH concentration, the triangular-shaped MF was used for time. The functions were determined following trial and error.
    2.3.2. Defining fuzzy rules and application of fuzzy operators
    According to the measured values, the fuzzy intersection (Min) and union (Max) functions were used to multiply the inputs and combine the outputs, respectively.
    2.3.3. Defuzzification
    Defuzzification involves the production of a quantifiable output. As we applied Mamdani fuzzy inference method, we used the center of gravity technique for defuzzification. All defuzzification calculations were performed using relevant software and the output was quantified for various inputs.
    Results And Discussion
    TPH concentrations in treatments with sorghum and barley and also unplanted (control) treatments demonstrates that, increasing depth was associated with higher concentrations of TPH and smaller differences between the treatments. More precise, TPH concentrations of control and planted treatments were significantly different at the 0-25 cm depth (P
    Conclusion
    The present study designed a fuzzy model to determine TPH concentrations during the phytoremediation process in lands adjacent to Isfahan Oil Refinery. The measured concentrations decreased by 52%-64% in soils planted with sorghum and barley. These rates were 23%-35% greater than the values obtained from unplanted treatments. Since even small amounts of organic contaminants can seriously threaten human health, enhanced elimination of petroleum-based contaminants in presence of sorghum and barley plays a critical role in improving soil conditions in the area. On the other hand, not only is the quantitative measurement of TPH a difficult, time-consuming, and costly task, but it also requires access to different depths of soil during phytoremediation (which is not always possible). Therefore, we determined the concentrations at different times and depths by developing a fuzzy model. The applied model was actually able to mathematically formulate the existing limitations and facilitate decision-making and inference through its simple, flexible concepts.
    Considering the novelty of fuzzy logic techniques in soil and water resources studies, particularly in Iran, further, more diverse research on the application of such methods in various fields of integrated soil and water resources management can lead to improved prediction and modeling accuracy at lower cost and time. As the values calculated by our fuzzy model were consistent with the measured TPH concentrations, this model can also be utilized in other contaminated areas. Meanwhile, the model comprised 10 different MFs (four for depth, two for time, and four for the output) whose parameters could be modified by the user and thus alter the numerical value of the output. Since selecting appropriate values for the parameters is complicated, future studies are suggested to use optimization methods such as genetic algorithms determine the best parameters for MFs.
    Keywords: Soil Pollution, Oil Pollutants, Depth of Pollution, Fuzzy Model
  • Ali Shahidi, Abbas Khashei, Siuki, Zahra Zeraatkar* Pages 827-840
    The potential sources of Cr (VI) are various effluents from metallurgy, electroplating, leather tanning, textile dyeing, paint, ink, and aluminum manufacturing industries. These industrial effluents can contain Cr (VI), in the concentration range of 10 to 100 mg/L (Nakano et al 2000), which is much higher than the standard limit; 0.5 mg/L in industrial wastewater (EPA). In aqueous systems, chromium usually exists in both trivalent [Cr (III)] and Cr (VI) forms. Although Cr (III) is considered an essential trace element, Cr (VI) is toxic, carcinogenic, mutagenic and teratogenic (Wittbrodt & Palmer 1995). Therefore, the removal of Cr (VI) from industrial wastewater is of particular concern. Advances in water and wastewater treatment technology need spur for the development of technologies that may be more effective and less costly. Nowadays, the contamination of water by toxic heavy metals through the discharge of industrial wastewater is a worldwide environmental problem that this pollution can also have a source of groundwater with the geological formation. There are various methods for removing heavy metals including chemical precipitation, membrane filtration, ion exchange, liquid extraction or electro-dialysis (Park 2007). However, these methods are not widely used due to their high cost and low feasibility for small-scale industries (Elangovan 2008). The widespread industrial use of low cost adsorbents for wastewater treatment is strongly recommended at present, due to their local availability, technical feasibility, engineering applicability and cost effectiveness (Girgis 2002; Serrano 2004). Most agriculture wastes or by products are considered to be low value products. As an alternative, a variety of inexpensive biomasses have been studied for their ability to remove Cr (VI) from aqueous solutions. Among these low cost adsorbents are microorganisms, seaweed, clay minerals, agricultural wastes, industrial wastes and various other low-cost materials (Bailay et al 1999; Dokken et al 1999; Park et al 2001; Selvi et al 2001; Rao et al 2002; Babel & Kurniawan 2003; Lakatos et al 2003; Yu et al 2003; Kobya 2004; Bishnoi et al 2004; Gupta & Ali 2004; Chun et al 2004; Grag et al 2004; Sheng et al 2004; Kobya et al 2005; Khezami & Capart 2005; Prasenjit & Sumathi, 2005; Sen et al 2005; Khosravi et al 2005 ; Verma et al 2006; Potgieter et al 2006; Wang & Qin 2006; Zulkali et al 2006; Yasemin et al 2007; Sciban et al 2007; Gerente et al 2007; Igwe et al 2007; Cetin et al 2007; Benhima et al 2008; Rocha et al 2009; Jaman et al 2009; Miralles et al 2010; Boudrahem et al 2011; Anwar et al 2010; Revathi et al 2012 ; Bai et al 2011; Ramalingam et al 2012). The dynamics is an essential aspect of the adsorption process especially for practical applications. Therefore, the present investigation has been undertaken for studying the dynamic behavior of adsorption through batch experiments performed under different conditions of contact time, pH, adsorbent, initial concentration, particle size and temperature. A well-fitted kinetic equation was used to evaluate the suitable operational conditions for the removal process, and a Langmuir-type isotherm was modeled using kinetic data and experimental results.
    Matherials &
    Methods
    Preparation of the soluble metal The stock solutions of Cr (VI) (1000 mg/l) were prepared by dissolving K2Cr2O7 (analytical reagent grade) in distilled water. The desired Cr (VI) concentrations were prepared from the stock solution by making fresh dilutions for each sorption experiment. The initial pH of the solution was adjusted by using a solution of HNO3 or NaOH.
    Preparation of adsorbent:Barberry roots were collected from South Khorasan, Birjand areas and soaked in distilled water for 24 hr before putting in an oven at 70°C for 24 hours. Barberry roots using Mill Were powdered. Powders were sieved through a 100 mesh and were stored in a container away from moisture.
    Batch adsorption experiments: Adsorption experiments were carried out in batch mode. In order to investigate the nature of Cr (VI), initially the effect of pH on percentage removal was carried out and then further experiments on the effect of contact time, adsorption weight, initial concentration and temperature were conducted by using optimized pH. Only one parameter was changed at a time while others were maintained constant. In the first set of experiment, percentage adsorption was studied at various pH of (1.5–9) at constant adsorbent weight of 0.1 g/100 ml, initial Cr (VI) of 50 ppm and the predetermined time (10min) in a rotary shaker at a speed of 200rpm using series of 100 mL Erlenmeyer flasks. Next second set of experiments were conducted with various contact time, initial Cr (VI) concentration (50ppm) at constant adsorbent weight (0.1 g/100 ml) and at optimized pH 1.5. In the third set of experiment adsorption weight was varied (0.05–1 g/100 ml) while other parameters such as initial Cr (VI) concentration (50 mg/l), optimum time (90min) and optimum solution pH kept constant. In the fourth set of experiment Cr (VI) concentration was varied (25–200 ppm) and in the last set of experiment, temperature was varied at six different temperatures viz., 22, 25, 35, 40, 45 and 50°C in a thermostat attached with a shaker. The constancy of the temperature was maintained with an accuracy of ± 0.5 ºC.22-50), and other optimum parameters kept constant. After completion of every set of experiments the supernatant was separated by filtration using Whatman filter paper and only 10ml of each sample was stored for residual chromium analysis. The pH of each solution was adjusted using required quantity of HNO3 or NaOH before mixing the adsorbent. Three replicates per sample were done and the average results are taken for calculation. The filtrate was analyzed using Atomic Absorption Spectrophotometry (AAS) (Shimadzu AA-6300; 228.63 nm). All the experiments were performed in.
    Keywords: Barberry root, Cr (VI), Heavy metals, Removal, Wastewater
  • Saeed Skandari *, Ali Torabian, Gholamreza Nabi Bidhendi, Majid Baghdadi, Behnoush Aminzadeh Pages 841-854
    Introduction
    Conventional water treatment consist of unit processes include coagulation, flocculation, clarification, filtration and disinfection that goal is removal of turbidity, color and certain bacterial species. In filtration process flocculated substances that have not removed in pervious stage are sediment. Filter media is often silica sand that removal mechanism is complex and consists of mechanical filtration, sedimentation, adsorption, chemical and biological oxidation. The effective removal mechanism in filtration process is adsorption. Two basic factors for adsorption are van der walls force and mass attraction. Sometimes for quantifying and qualifying upgrading of filters, we use other media such as granular activated carbon and anthracite, that in these cases filters have dual media. Activated carbons (ACs) are effective adsorbents in water treatment, because of high removal capability toward soluble and particulate pollutants but slow adsorption kinetics and difficulty for regeneration limited extensive application. Todays, progresses in new technology result in production of other carbon structures such as carbon nano tubes (CNTs). CNTs with mesopore structures and diameter about 2 - 50 nanometer have high potential in organic materials and pathogens removal. Removal of organic matters with carbon nano tubes are in groups such as organic dyes, pharmaceutical, pesticides, phenol, aromatic amines and natural organic matters. Adsorption mechanisms of CNTs are driving including hydrophobic effect, π–π interaction, π–π electron-donor-acceptor (EDA) interaction, electrostatic interaction and hydrogen bonding. Although good potential in organic removal, using in slurry state is a problem that it is necessary to remove CNTs in final treatment. So, if we can capable to deposition these CNTs on media, we can solve this problems. One way to use is deposition of CNTs on silica sand. Although silica sand has adsorption capability, with deposition of CNTs it can remove soluble organic matters. Similar to this coating graphene oxide (GO) was deposited on silica gel that new adsorbent used for mercury and rodamin B removal in batch and continues experiments. One of the shortages in this research was inattention in stability of coating. In other research, pristine single wall carbon nanotube was coated on silica sphere and a method based on non-covalent bonding was represented. The result of this research shows that, bonding has a strong stability.
    Methods
    In order to deposition of CNTs on silica sand, physical and chemical processes were used. In physical process heat and in chemical process covalent bonding is effective factors for bonding. Materials that used in this research are carbon nano tube (purchased from nanosov), hydrochloric acid37% (Merck, Germany), nitric acid 65% (Merck, Germany), silica sand (gift from Tehran pars plant) and 3(triethoxysilyl) - prophylamin (Merck, Germany). Whereas heating may reinforce the bonding between carbon nano tube and silica sand, define temperatures was used to evaluate temperature effects.
    For evaluating adsorption effects, 4 parameters (pH, adsorbent dose, adsorbate dose and contact time) was investigated. In this study initial pH at neural condition, initial adsorbent in 5-40 gr, initial adsorbate in 2- 12 mg /l and contact time in 10 – 60 minutes was adjusted. For preparation different concentration of TOC a 1000 mg/l stock solution of TOC was prepared and TOC analyzer (model -VCSH, Shimadzu, Japan) for determination of TOC was used.
    For reversibility of humic acid from surface of new adsorbent adsorption/desorption studies was investigated. So in some series 20 g of engineered nano adsorbent was entered in 200 ml solution of humic acid with initial TOC of 10 mg/l and when adsorption process was equilibrated the adsorption capacity was measured. After that the new adsorbent was poured in 200 ml solution that pH was adjusted from 10-13 with 0.05 and 2 molar NaOH to attain optimum pH. Also desorption time for 10-50 minutes for evaluating optimum time was done. Finally desorption process at 25ºc, 120 rpm and for 5 cycles was repeated.
    Results And Discussion
    Investigation method of chemical bonding The method of chemical deposition is establishment of covalent bonding between amin groups of silica and hydroxyl groups of oxidized carbon nano tube. So first, silica sand is hydrolyzed to active OH groups. Then silica sand and amin prophyl is combined to produce NH2 groups and finally oxidized carbon nano tubes and amin groups of silica sand is heated to be resulted –NH groups that is a strong bonding.
    Stability of MWCNTs coated on sand
    To investigate stability of MWCNTs coated on sand, ultrasound method was used. Ultrasounds are mechanical waves with high power that disperse in adsorbent to detach CNTs from surface of silica sands. These waves have 40 khz dispersion power frequency. So 6 samples (firstly physical and chemical samples, physical and chemical samples was heated in oven in 100ºc and physical and chemical samples was heated in oven in 200ºc) was putted in the ultrasound bath for 30 min and after that samples was dried and it was seen that physical deposition has not stability and the MWCNTs coated on sand detached from silica sand, but chemical deposition has a strong stability and in samples that was putted it in 200ºc in oven, this stability is very permanent that demonstrate high temperatures has good effects on stability.
    SEM of MWCNTs coated on sand
    SEM was used to detect possible morphological changes in pristine and oxidized MWCNTs and also for watching surface of silica sand and MWCNTs coated on silica sand. According to SEM, oxidized MWCNTs with nitric acid, some bundle appear exfoliated and curled and a major alteration of the structural integrity of MWCNTs is observed and length of tube was shortened. On the other side, observation of CNTsand illustrate a non uniform coating of MWCNTs on silica sand that completely differ from surface of silica acid treatment.
    Investigation potential of CNTsand in removal of organic matter
    Although MWCNTs potential in removal of organic matter has been demonstrated in some previous research, in this study humic acid was used for index of organic matter to define capability of this adsorbent. So response surface methodology was used for experiment design and initial concentration of adsorbent, adsorbate and contact time was investigated and 20 experiments were defined. According to response from RSM- X/M (mg/g) – with increasing in contact time and decreasing in adsorbent dose the adsorption capacity was increased. Also with increasing in contact time and increasing in adsorbate dose, adsorption capacity is increased that be because of increasing in adsorbate collision with adsorbent. The equilibrium time is about 60 minutes and adsorption capacity at equilibrium time is reached to above 70 mg/g
    Regeneration of adsorbent
    To evaluating regeneration of adsorbent the adsorption/desorption process was investigated. Data obtained indicate at pH =10 the regeneration efficiency is about 26.3% and increases up 75.7% at pH=13. Also 30 minutes is the best time for regeneration time and after 5 cycles of regeneration, the adsorption capacity is about 40 mg/g.
    Conclusion
    Although silica sand is not applicable to removal of soluble organic matter, but by deposition of carbon nano tubes onto its surface, it can capable to remove this organics. Stability investigations indicate that physical coating has a week bonding between silica sand and carbon nano tubes. In chemical bonding that establish a covalent bonding between silica sand and carbon nano tubes, bonding has a strong stability. Scanning electron microscopy (SEM) on silica surface reveals a non uniform coating of carbon nano tubes on silica sand. Determination of TOC shows in sample with CNTsand , adsorption capacity is higher than to 70% and in sample with raw sand is less than 1%. Regeneration studies indicate that the optimum pH is 13 and optimum time for desorption is 30 minutes. Also after 5 cycles of regeneration the adsorption capacity is about 40 mg/g. These experiment show that the new adsorbent - CNTsand - has a good potential in organic matter removal and regeneration process is simple.
    Keywords: sand filter, silica, carbon nanotube, organic
  • Mohammad Ghalebizade, Bita Ayati* Pages 855-865
    Introduction
    Synthetic dyes and specially azo dyes are common pollutants found in textile and dyeing industries effluent. azo dyes are the most important class of synthetic dyes and and represent about 70% of all world dyes consumption. Textile effluent can cause considerable pollution and rise high health risk factors due to loos of 20% of dyes in process and large scale of dyes used in these industries. The characteristics of the textile wastewater are high color intensity and visibility in very low concentrations, complex chemical structures, and light resistance and hard to biodegradability, variability in pH range and above of these they have high carcinogenic and mutagenic potential.
    Generally, the physical, chemical and biological methods were used for treating textile wastewater can be mentioned as electrocoagulation, adsorption, Fenton, photo-Fenton and photo-catalytic process.
    In recent years, advanced oxidation technologies have been described as efficient procedures to obtain high oxidation yields from several kinds of organic compounds. These methods mineralize and converse pollutants into CO2, H2O and inorganic ions, by the action of hydroxyl radical, which acts as a nonselective and strong oxidant of organics.
    Electro-Fenton is a common advanced oxidation processes which contains electrochemical production of H2O2 and Fenton process that makes each process more efficient. Its advantages are low operation cost, high potential for complete destruction and removal of organic pollutants into harmless compounds such as CO2, water and mineral salts. Electro-Fenton Process involves the reaction of a homogeneous organic contaminants with strong oxidants, H2O2 that produced by injecting air into water near the carbon electrode cathode and the iron ion as catalyst produce hydroxyl radical which eventually led to the decomposition of organic compounds.
    Materials And Methods
    In this study, electrochemical process was developed at ambient temperature in a 500 mL rectangular plexiglass cubic reactor which includes two electrodes, an anode made of 304 stainless steel and a graphite cathode placed 3cm from each other and a PM-3005D power supply. Air was blowing in the cathodic zone by an RS Electrical 610 air generator pump and an IKA RH-Bassic 2 magnetic stirrer was used to mix and homogenize the sample. The other equipments used in this study include a Kern PLS 360-3 digital scale with 0.001 accuracy and Metrohm 691 pH meter. The amount of dye in solution is measured by using a Hach DR-4000 spectrophotometer at a wavelength of maximum absorption of acid orange 7 (485 nm) and the calibration curve of dye concentrations, respectively.
    In this study, several parameters including current intensity (0.3, 0.6, 0.9 and 1.2 A), aeration rates (0, 3.5 and 7 L/min), electrodes area (30, 60, 90 cm2), initial pH (2, 3, 6.5 and 9) and energy consumption were examined.
    In order to maintain the flow of electricity in the cells, Na2SO4 (Merck) 0.01 M was used. All experiments were performed according to the method of analysis of water and wastewater.
    Results and Discussion
    3.1. Effect of current intensity
    The influence of current intensity has been investigated in the range of 0.3 to 1.2 A., when current intensity was 0.3, dye removal efficiency was 71% after 120 min reaction. Increase of current intensity to 1.2 A could enhance dye removal efficiency to 94%, caused by increasing production of ferrous ions and hydrogen peroxide that results to enhance the production of hydroxyl radical. When the current intensity was increased further, excessive hydroxyl radicals would be consumed via following side reactions which may reduce the dye removal efficiency.
    Fe2 OH0 → Fe3 OH- (1)
    H2O2 OH0 → HO20 H2O (2)
    OH0 → O2(g) 2H 2e- (3)
    Due to the dye removal efficiency at current intensities of 0.6 and 1.2 A were approximately equal, the current intensity of 0.6 A was selected as the optimum level with lower power consumption than other cases (0.24 KWh/ppm).
    3.2. Effect of air flow
    Increasing the air flow rate from 0 to 3.5 L/min resulted in an increase of the acid orange 7 removal efficiency from 80 to 90 percent at 150 min. The removal efficiency remained constant when the air rate was increased to 7 L/min. The experimental results indicated that increasing air flow leads to increase hydrogen peroxide and enhance dye removal efficiency by improving production of hydroxide radicals, But further increase in air flow would lead to reduce removal efficiency by consumption of hydroxide radical with exceed hydrogen peroxide (reaction 2).
    3.3. Effect of electrode surface
    The results showed that when the electrode surface were 30, 60 and 90 cm2, the degradation percent of acid orange 7 after 300 min were 68, 89 and 97 percent, respectively. However by increasing time reaction, dye removal reaches to constant value. It was well known that the amounts of electro-Fenton reagents would be increased by enhancing electrode surface and result in increasing dye degradation.
    3.4. Effect of initial pH Due to the direct production of hydrogen peroxide in situ, the highest dye removal efficiency was obtained at pH=2 because in this pH, H2O2 is more stable and could be produced more efficiently. Anyway, increase the initial pH lead to reduce dye removal efficiency in the first 60 minutes. Dye removal efficiency is decreased by increasing the pH to the neutral and alkaline ranges because of the formation of ferric hydroxide species, reduction in the ferrous ions reproduction and reduction in hydrogen peroxide generation. The results show that the dye removal were 76, 64, 62, and 55 percent, with initial pH of 2, 3, 6.5 and 9 at 60 min electrolysis respectively. However with increasing time reaction, efficiency of dye removal improved at initial pH of 6.5 to 95 percent at 180 min electrolysis. So initial pH of 6.5 was selected as optimum condition for reducing chemical material for releasing wastewater into the environment.
    Conclusion
    This paper has considered the electro-Fenton treatment of an azo dye with producing in situ hydrogen peroxide by oxygen reduction on graphite cathode. The effects of current intensity, air flow rate, initial pH and electrode surface were investigated. The experimental results showed that electro-Fenton process is able to decompose organic compounds without producing sludge as well as the oxidizing agent (H2O2) that produce only oxygen and water, so this process can be used for treatment or pre-treatment of wastewater containing toxic and non-biodegradable materials, especially textile effluents. From the obtained results, after 300 min of electrolysis, 90 percent dye removal was achieved under optimum condition (current intensity= 0.6A, pH=6.5, no aeration, electrode surface= 60cm2 and energy consumption= 0.24KWh/ppm), which shows electro-Fenton is the proper way to degrade acid orange 7.
    Keywords: Wastewater, Acid Orange, Electro Fenton, Electrode Surface, pH
  • Saeed Taheri Ghannad *, Ali Afrous Pages 867-878
    Introduction
    Water pollution by heavy metals is a worldwide environmental problem due to the increasing exploitation of mining activities, industrialization and urbanization has increased around the globe. Lead is the most important environmental pollutants that contaminate soil and water resources from different ways. This element is including the most toxic heavy metals in the United States Environment Organization. Therefore refining of soil and water contaminated with this element is from most important environmental policies of developing countries and Industrial countries. Lead metal is unnecessary for the body, so that trace amount in the body, indicating contamination with this element. Lead substitute for calcium in the cells and disrupt the activities of the body. Also cause liver and kidney dysfunction, genital organs and reproductive system, anemia, loss of intelligence interest and occurrence of the metabolic complications. Remove and control pollution of heavy metals is very difficult due to their multiple and different sources of pollutions. Because each pollutant requires its refining process. Until now, many methods have been developed for the purification of sewage including can be pointed to the chemical precipitation, reverse osmosis and ion exchange of organic. Each of which has its own advantages and disadvantages. Including the optimal method of biological for the removal of pollutants is the use of plants and other expression Phytoremediation.
    Materials And Methods
    Project preparation and cultivation of plants In order to implement this study, plastic pots prepared with 60 cm in diameter and 40 cm in height. Therefore from sand with grains diameter of 1 to 5 mm and a depth of 30 cm was used as the growth bed in pots that after preparing the pots and planting, were placed a suitable interval each other. Selected plants included Phragmites, Thypha and Cynodon Dactylon selected due to their abundance in the are. Young plant samples were collected from margins of wetlands, open surface drains and rivers and immediately were transferred to the site of the research in experimental field of Islamic Azad University of Dezful. After preparation of bed and adding nutrients to the cultivation medium, each pot was randomly assigned to a treatment in three replicates. The youngest seedlings were selected for cultivation in each medium sample. After gentle washing of seedlings with water, three plant at regular intervals, with the minimum distance of 5 cm from wall of the container and at a depth of 10 cm (density of 25 plants per square meter) were cultivated. After preparing the pots and planting the desired species were irrigated with the common water for 40 days because irrigation with synthetic wastewater in the early stages of cultivation caused stress to the plant due to lack of root stability and compatibility with the new culture medium. So after the elapse of this period time, irrigation with simulated wastewater in different concentrations of 5, 10 and 15 mgr lead/l is performed.
    Results And Discussion
    Exponential Association regression model Exponential Association regression model using curvexpert software was used in order to simulate the kinetics of uptake in different treatments. The general form of this model is as . In this equation, t in day and y lead uptake in milligram per kilogram of soil was defined. Lead absorption curves have been showed for Cynodon, Phragmites and Thypha in the treatments of average level of lead concentration. In this diagram, the regression coefficients a and b are variable constants for the different species and under different levels of concentration. According to this model, the kinetics of adsorption was highly correlated. Therefore, these equations can be used to simulate the removal of lead at different concentrations. The results showed that with increasing levels of concentration, the correlation coefficient was reduced. So this model in the medium and high levels had high precision. Comparison of model in the studied species showed a correlation coefficient of reed was much higher than the other two species so had better fit to this plant. Therefore, these equations can be used to simulate the absorption of lead at different times and in different plant species, especially reed with the high correlation coefficients.
    Fitting with other models of the kinetics
    Due to the lengthy process of phytoremediation, the use of appropriate models to simulate and calculate the necessary time for refining the soil and reach the optimal level is essential.
    For this purpose, in addition Exponential Association model, models of zero order kinetics (linear function), first order kinetics and power function were selected and with the data collected were fitted. Results showed the first order kinetic model in all treatments had a correlation coefficient (r) higher and consequently the lower from standard error (s) than the linear model. Comparison first order kinetic model with Power model showed that power function had a higher correlation coefficient. Therefore, it is suggested that from power model to be used simulating kinetic Lead with the high correlation coefficient.
    Conclusions
    Experimental results showed that the kinetics of the reduction of lead in soil was mainly in the form of an association exponential model and then power model had the best correlation coefficient compared to the other models. The results showed that these two models had better performance and matching during the entire period of experiment. Whereas zero order and first order kinetics models at the initial and final times were not accurate. The results of the calculation of the equilibrium time to achieve half the initial concentration in the soil (y / 2) showed that as the first order kinetics model, times 384, 190 and 100 days respectively by cultivation of Cynodon, Typha and Phragmites required in conditions treatment of the mean levels of wastewater concentration which implies that Phragmites had greater potential for Phytoremediation than the other two species. Therefore bed concentration was reached in less time by half the initial concentration of the soil lead. The results showed that the reaction rate constant for the three species varied in the range 0.0014 to 0.0071 day-1 that this amount was higher for Phragmites than the other species. Thereby reducing rate of soil lead by Phragmites cultivation was faster than the other two species and this constant coefficient in all cases was decreasing with increasing the different concentration levels of wastewater. In the end it was concluded that the kinetics of phytoremediation should be simulated based on plant type, levels of concentration and type of contaminants.
    Keywords: Phytoremediation, kinetic model, lead removal, aquatic plants
  • Mehri Shabani *, Mohammad Hosein Sayadi, Mohammad Reza Rezaei Pages 879-886
    Introduction
    Nowadays, cultivation of microalgae in order to reduce CO2 has gained attention all around the world. One of the outstanding features is that photosynthetic efficiency of microalgae is greater than that of terrestrial plants. Carbon dioxide (CO2) has been known as one of the most important greenhouse gases. Global warming is specially caused by Anthropogenic CO2 emissions from fossil fuel utilization especially from coal combustion. Co2 emissions are expected to rise in the coming years because of energy needs increasing in the developing worlds. So many attempts have been made to reduce atmospheric CO2 including chemical absorption, physicochemical adsorption, membrane, cryogenics, chemical looping combustion (CLC) and biotechnology (e.g., terrestrial vegetation or hydroponic algae). Bio fixation via microalgae has been known as a potential and new method for CO2 capture and storage. So one of the most understudied methods is carbon biosequestration whereby autotrophic organisms and plants convert this CO2 into organic carbon through photosynthesis producing large amounts of biomass. Photosynthesis is the original process that created the fixed carbon present in today’s fossil fuels, and microalgae are the origin of these fuels. They are among the fastest growing photosynthetic organisms, using CO2 as their main building blocks. Environmental factors, particularly light, temperature, nutrient status, and salinity, affect photosynthesis and productivity biomass. In order to assess the potential of a microalgae system for directly removing CO2, biomass measurement or growth rate evaluations are necessary. However most studies have focused on culturing microalgae in fresh water according to water quality in most part of Iran, in the present study, we tried to sequestrate CO2 by Chlorella vulgaris under salinity water.
    Materials And Methods
    Pure stock culture of Chlorella Vulgaris was obtained from National Inland Water Aquaculture Institute Bandar-e Anzali, Iran and cultivated in Bold's Basal Medium (BBM). Culture of Chlorella vulgaris were individually cultivated in three (9.3 liter working volume) flat plate reactors(40*40*40) under three different EC; artificial seawater (EC34000 µS/cm) , distilled water (EC 3 µS/cm),natural water in study area (EC 1500 µS/cm).(measured by EC meter, Istek Model 915 PDC). The cultures were maintaining under a 12h dark/light photoperiod with 3500 Lx of illumination for 8 days. The average pH of natural water was 7.83 and hardness of 1000mg/l, the amount of carbonate and bicarbonate were 4 mg/l 339.7 and its electrical conductivity was 1500 µs/cm. The amount of initial dissolved CO2 was 8 ppm .Agitation and aeration were accomplished using air from a compressor with pressure of 0.12 MPa. All tests were taken on laboratory conditions and under ambient temperature so the temperature were 25-31°C with an average temperature 28°C. Direct microscopic cellcount by Thoma haemocytometer was performed in this study using optical microscope. Microalgae dry weight (g /L) was measured by centrifuging 10 ml of each sample at 4500 RPM for 30 minutes and then washed with deionized water. Finally dried at105 °C for 40 minutes. After measuring the dry weight, the amount of biomass productivity (P), growth rate (µ) and carbon biofixation rate (R) would be achieved by using equation 1-3.
    Poverall (g /L/d= ((xt-x0)/ (tt- t0) (1)
    µ (day-1) = (ln (xt/x0))/ (tt- t0) (2)
    Rco2 (gCO2 L-1 d-1) =Cc P (mCO2 mC−1) (3)
    Where:Where xt and x0 were the biomass (g/ L) on days tt and t0, respectively . Cc is the carbon content of the microalgae cell (%, w/w) measured with elemental analyzer; mCO2 is the molecular weight of CO2; and mc is the molecular weight of carbon.
    Statistical analysis
    In the present study, the raw data were stored in Ms Excel and then the relationship among biomass production, specific growth rate and bio-sequestration rate of CO2 with the different level of salinity were interpreted by Tukey analysis using SPSS (version 17) software
    Results And Discussion
    Nowadays The use of micro-algae cultivation to reduce carbon dioxide has attracted a lot of intrests around the world, the higher rate of photosynthesis in these organisms rather than plants and crops is one of their and distinctive features. In the present study the pure stock culture of Chlorella vulgaris cultivated in Bold's Basal Medium was used. The microalgae were cultivated in 3 treatments and 3 replications containing pure water, artificial sea water and natural for 8 days. Lighting conditions provided for this test were periods of 12 h dark / light with light intensity of 3500 Lux.
    The results of maximum concentration of biomass, maximum specific growth rate and maximum CO2 fixation for the cultures under different EC are presented in Table 1.
    Table 1- the parameters of productivity, specific growth rate and carbon fixation rate of chlorella vulgaris during 8 days.
    Culture Biomass productivity (P)
    (g L-1 d-1 ) Specific growth rate (µ)
    (d-1) Carbon fixation rate (R)
    (gCO2 L-1 d-1 )
    1-4 4-6 6-8 1-8 1-4 4-6 6-8 1-8 1-4 4-6 6-8 1-8
    Pure water
    )EC= 3 µs/cm) 0.090 0.020 0.028 0.057 0.266 0.035 0.045 0.15 0.148 0.033 0.045 0.093
    Artificial sea water
    )EC= 34000 µs/cm ) 0.033 0.010 0.025 0.025 0.025 0.007 0.018 0.019 0.053 0.016 0.041 0.041
    Natural water
    )EC=1500 µs/cm ) 0.078 0.050 0.065 0.068 0.182 0.077 0.085 0.131 0.127 0.082 0.107 0.111
    As table 1 shows the biomass productivity of Chlorella sp. In pure water, artificial sea water and natural water was 0.057, 0.025 and 0068 g/L/d respectively that presented higher biomass productivity in natural water. Specific growth rate of 3 culture was 0.15, 0.019, and 0.13 (day-1) respectively, which the lowest one belongs to artificial sea water (high salinity). Carbon fixation rate of 0.093, 0.041 and 0.111 g/L/d was observed in pure water, artificial sea water and natural water.
    Table 2- Average cell numbers of Chlorella vulgaris per liter counted during 8 days of cultivation
    8th day 6th day 4th day 1st day Cell counted
    (per Liter)
    Culture media
    10*107 8*107 7*107 3*107 Pure wter
    6*107 5*107 5*107 3*107 Artificial sea water
    12*107 9*107 6*107 3*107 Natural water
    According to table 2 the most number of cells were counted in natural waters at the end of the eighth day. In the artificial sea water because of the high salinity and inappropriate environment the cell growth and proliferation was slow, so that it shows the ability of carbon sequestration in the environment with high salinity was low.
    Tukey statistical results showed that there is significant differences at p≤0.05 between biomass production, growth rate, atmospheric carbon fixation rate, and also the number of cells in different salinity treatments. So amounts of salinity have resulted in different effects on the growth rate and carbon fixation rate.
    Conclusion
    Due to lack of enough fresh water sources, hot, dry climate of study area and inappropriate plants growing conditions, using microalgae is one the best solutions in order to stabilize greenhouse gases (carbon dioxide) and other applications such as the production of renewable fuels and medicinal uses. According to the results of present study, the maximum biomass and cell growth was observed in natural water able environment for freshwater microalgae, so the carbon sequestration potential of microalgae in the culture medium with high salinity is low. Despite being a fresh water microalgae, chlorella vulgaris presented high growth and fixation rate in natural water (EC=1500), so it could be cultivated in study area (South Khorasan, Birjand).
    Keywords: Birjand, Carbon sequestration, Chlorella vulgaris, greenhouse gases, Salinity water
  • Ali Vosoogh *, Mohsen Saeedi, Raziyeh Lak Pages 887-908
    Introduction
    In recent years, restrictions of fresh water resources in the world and protection of the quality of these resources cause attention of many scientists about pollution of aquatic fresh waters like rivers. One of the most river pollutants is heavy metals. Unlike the organic compounds, these elements do not disintegrate by natural processes and have toxic potential risks for living organisms and environment. Metals are the natural components of water ecosystems and most of them are necessary for organisms. Only when the contents exceed from the limitation, they can water pollutants. It is general phenomenon that metal contaminants in aquatics accumulated mostly in fine sediments. Accordingly, few studies have been done about heavy metals pollution in size fractioned sediments. This study aims to examine the changes of heavy metals concentration
    in Sefidroud size fractionated sediments as one of the most important and largest river in the country using some common pollution indices. Finally, It also assessed the sources of heavy metals by using multivariate statistical analysis.
    Materials And Methods
    The study area was Sefidroud river in south west of Caspian Sea ,that have been located within Gilan Province .Its catchment area is about 14041km2 and is located between 50° 36' 00"and 48° 34' 00"E longitude and 38° 27' 00"and 36° 34' 00"N latitude. According to Iran Meteorological Organization reports, Gilan Province is the most rainy province with an average of 580 mm rain per year in Iran.
    The Talesh Mountains and the western Alborz belt as gigantic barrier is located between this territory and Iran inland. This is the only natural connection of the Gilan territory with Iran inside plateau, and is through the Sefidrood valley. Gilan Province is composed by two following regions: The lowlands, adjacent to Caspian Sea and the mountainous region.
    Moreover, important and interesting particularities of Gilan Rivers include a massive hydrographic network with a large number of rivers as well as high range of water flow in the rivers. The inundating rivers, is created by transporting circular stone pieces and blocks through under-washing the ridges overlooking the farms and orchards, threaten the cultivated areas and gardens.
    According to the Iran Ministry of Industries and Mines data 60 active and 19 abounded mines are located in study area that may release heavy metals into the environment. Coal mining activities are of the examples of mine type in the catchment area.
    Sampling sites were located on different geological formations in the catchment areas of the Sefidroud river. Five surface sediment samples were taken from this river from upstream to estuaries during June to July 2013.Surface sediment samples were collected by mini Ekman type grab sampler. All samples were transferred to the laboratory in sealed plastic bags under 1 to 4 °C. Grain-size analysis was carried out using wet standard sieving methods for particles larger than 38µm using sieve shaker (Analysette 3 Pro, Fritsch) and laser grain size analyzer for particles less than 38 µm (Analysette 22, Fritsch) at the Research center for applied geology, Geological Survey of Iran, Sediment logy Laboratory.The 5 collected river samples were separated into six particle size ranges; Discussion of
    Results
    - Size fractioned river sediment Generally, size fractioned river sediments is used for a preliminary physical characterization of sediment samples. This phenomenon is emphasized by more researchers that because of higher specific surface area in fine particles, larger pollutants such as heavy metals can present them. It was found that more than 29.1% of the river sediment particles at all of the sampling sites are between 250-500 µm.
    - Size fractioned sediments and metal pollution
    Total metal concentrations (Cu, Zn, Cr, Fe, Mn, Pb, Ni and Cd) and statistical parameters of 5 samples across the six particle size ranges,
    Conclusion
    The aim of this research is recognizing the contamination of Sefidroud river sediments and the effects of particle size.
    To reach the purpose of these research, heavy metals concentration in six sediment sizes were measured.
    Generally, the results of analysis showed that by reducing the particle size, the heavy metals concentration were more than average amount of sediments and Earth’s crust.
    Degree of sediment toxicity index showed that with decreasing of sizes, the indexes increasing. Finally, multivariate analysis showed that concentration of some metals like Cr and Ni were high because of anthropogenic sources. Other metals like Fe and Mn have natural sources.
    Keywords: Heavy metals, size fractioned sediment, pollution index, multivariate statistical analysis
  • Akbar Baghvand, Rahim Nasirzade *, Mohammad Ali Abdoli, Ali Vosoogh Pages 909-921
    Nonstop growth of urban population and concentration of industrial and agricultural activities in many parts of the world and Iran have given rise to increased demand for water for different uses .Furthermore, as one important factor of lack of exchange between human and environment resulting in wide exploitation from agricultural lands, mine extraction, and application of various industrial tools, increased population has no role except pollution and contamination. Within this framework, one can view the issue of pollutions from two perspectives of natural resource destruction and development of waste stemming from various consumer goods. It might even have caused great transformations in quality and quantity of waste in response to rapid development of human artifacts and production of chemicals after industrial revolution .Threat to groundwater by landfill sites has always existed in many parts of the world. In particular, in developing countries, as a result of industrial and household wastes, even when there is no hazardous waste at the landfill site, the resulting leachate is still a significant threat to groundwater.
    Although through immuring waste, hygienic landfill sites have brought about beauty and cleanliness to the environment and provided people and environment with health and hygiene, they will cause potential adverse effects due to generation of two by products, gas and leachate.
    Leachate consists of the extract from the passage of waters mainly ditch water through waste mass containing numerous contaminants. Gas is also produced at the landfill site in response to chemical decomposition and decay of perishable waste and food. This gas mainly consists of methane, some carbon dioxide and volatile organic acids . Although soil is the most important and widely used physical, chemical, and biological filter for waters, waste recycler, and a host for many substances, its capacity is limited and many toxins and materials added to soil may become more concentrated and in turn create serious threats to the environment . Greenhouse effects of methane and carbon dioxide gases, development of global warming, suffocation caused by carbon dioxide gas, and explodability of methane are among the effects brought about by gases emitted from landfill sites. The influence of methane gas on world atmosphere and greenhouse conditions is about 21 times as large as the effect of carbon dioxide .
    Takestan city is situated in southwest of Ghazvin between 46° and 42’ east and 36° and 4’ northeast (Fig. 1) with an altitude of 1265 m. Except for northwest and west of the city with a relatively steep slope, other regions of the city have a moderate slope. The general slope of the region extends from west to east and gradual decrease of slope has resulted in subsidence of remaining water of Abharrood and Kharrood rivers in the southern part. The maximum slope extending from northwest toward Takestan is around 3% and its average is 1.7% towards northwest. The general slopw of the region from Takestan toward Ghazvin northeastwards is approximately 0.3%.
    Takestan city, located in the plain of Ghavzin is restricted to Alinaghieh, Aghdagh, and Abuhanifeh altitudes from northern, northwestern, and western fronts situated at 7-15 km distance from the city. Regarding the limitation for development of the city in eastern and southeastern fronts, due to presence of vineyards and industrial lands at northeastern front of the city along with artificial barriers of development such as railways at the southern front, the only appropriate direction for urban development is the northwestern front limited by Tehran-Zanjan highway. On the other hand, since the region is earthquake prone and there are some known faults including Parandak, Ipek, Shtehard, Geshlagh, and Abyek, vertical development of the city is only possible by following Earthquake Code 2800 in urban constructions. The general slope of the city is about 2% from northwest to southeast and is 0.3% from west to east.
    Samples of groundwater and leachate were analyzed chemically in laboratory after sampling followed by measurement of heavy metal concentration together with BOD5 and COD.
    According to the main objective of the research, 5 sampling stations were specified within the study area from which water samples were taken in Mehr of 1393. In order to investigate the trend of qualitative variations, the obtained results were further compared with the results of 1393. Four sampling stations were selected from Takestan landfill downstream (A, B, C, D) and the fifth one (E) was selected from landfill upstream so that the potential effect of leachate on groundwater resource contamination within the study area be investigated more accurately. The leachate sample was further analyzed and the results were then compared with discharge standards. The studied parameters were electrical conductance, pH, TDS, TSS, BOD, COD, Na, Ca, and some heavy metals (including copper, zinc, iron, lead, chromium, cadmium, molybdenum, manganese, nickel, and aluminum).
    In order to analyze water standards qualitatively, some valid standards presented by Iranian institute of industrial research and standard, the standard of potable water in the country’s water industry, world health organization, and European Union potable water standard were used for drinking usages.
    The qualitative parameters measured regarding water sampling included pH, EC, TDS, TSS, BOD, COD, Na, Ca, and some heavy metals (including copper, zinc, iron, lead, chromium, cadmium, molybdenum, manganese, nickel, and aluminum).
    The comparison of qualitative parameters values in Takestan landfill leachate in 1383 and 1393 indicated reduced value of most qualitative parameters particularly heavy metals in 1393 in response to alterations of landfill reactions (acidic conditions to methanogen).
    The comparison of qualitative parameters values in leachate with the national standard of discharge to surface waters and absorbent wells manifested that Takestan landfill leachate both in 1383 and 1393 has had values (for most contaminants) over than national standard of discharge. Therefore, it should not spread into the environment easily and with no proper management.
    The comparison of analysis results of groundwater qualitative parameters within the study area revealed a significant increase of some contaminants particularly heavy metals. The probable reason could be leachate leakage to the environment and permeation to groundwater resources in the vicinity of landfill.
    Concentration of lead, cadmium, and nickel in water samples had the largest violation from national and international qualitative standards compared with other studied contaminants.
    Regarding the ascending trend of many studied contaminants (especially heavy metals) in water samples next to Takestan landfill, it can be stated that the leachate emitted from the landfill may have had a significant impact on the contamination of water resources around the landfill.
    Keywords: Takestan, Landfill, Leachate, Heavy metals, BOD5
  • Hosseini Norouz, Asghar Asghari Moghaddam *, Attaallah Nadiri Pages 923-942
    Introduction
    Management of groundwater, especially in dry regions such as Iran, is essential and this concern becomes further with development of agriculture, industry, population growth and climate changes, that affecting the quality and quantity of groundwater resources. Hence, groundwater contamination can treat the human health. Since groundwater moves slowly through the subsurface, the impact of anthropogenic activities may last for a relatively long time and for that reason, the environmental measures should be mainly focused on the prevention of the contamination. One of the ways to prevent of groundwater contamination is identifying vulnerable regions of aquifers and management of land use. The assessment of groundwater vulnerability maps requires the application of diverse methods and techniques, based on the hydrogeological knowledge of the region under research and on the application of predictive models. With the aim of deciding which areas are vulnerable a large data volume can be collected which cannot be effectively analyzed without an adequate and efficient model. Several methods have been devised to vulnerability mapping that relatively using fewer data and based on evidence of contamination. In this study to overcoming the problems of other methods the random forest (RF) algorithms is proposed.
    Materials And Methods
    Malekan plain is located in East Azarbaijan Province, Southeast of Urmia Lake, northwest of Iran, with 450 Km2. This region is one of the very active cultivated areas which its water demands supply by groundwater resources. In recent years groundwater quality of the area is encountered with degradation problem. Malekan region have different geological formations such as Lalon, Shemshak, Lar formations, and a large part of the area in the western part is an alluvial deposits of Quaternary. Aquifer of this Plain is unconfined, which mainly formed by old and recent alluvial terraces, alluvial fans and fluvial sediments. Based on drilling wells logs and geophysical data, the west part of the plain is made of fine grained material with low permeable.
    According to farming and existing of grape farms in this region and intensive use of fertilizers and manure the groundwater nitrate concentration of the aquifer is high (Figure 1).To evaluate the quality of groundwater resources, especially the assessment of nitrate anomalies in groundwater of the Malekan plain, 27 samples were collected from groundwater resources in September 2014, and Hydrochemical analysis were carried out in Hydrology Laboratory of Tabriz University. In this study the random forest (RF) algorithms, which is a learning method based on ensemble of decision trees, is proposed. The RF technique has advantages over other methods due to having, high prediction accuracy, ability to learn nonlinear relationships and ability to determine the important variables in the prediction. In this paper RF method is used to estimate the Malekan Aquifer vulnerability, with four sets of data, including A model with all variables, B model with variables related to characteristics of the aquifer, C model with driving forces variables, and D model with variables related to the DRASTIC method. The predictions derived from all possible parameter combinations were evaluated using the root mean square error (RMSE) and mean square error. The area under the curve statistic (AUC) was used to determine which models and which combination of dataset performed better. An AUC value of 1 is considered perfect.
    Fig1. Spatial distribution of nitrate concentration
    Results And Discussions
    From 23 explanatory variables used in model, five variables (depth to water table, hydraulic conductivity, distance to grape farms, hydraulic gradient and transmissivity) can describe the nitrates behavior in the Malekan plain aquifer with more accuracy, since a smaller MSE was obtained. In order to obtain continuous and standardized variables for all area of the study, all data were transformed into a raster format, and where were applied mainly three different approaches: 1) geostatistical techniques (e.g. hydraulic conductivity, hydraulic gradient and soil texture), 2) Euclidian distance raster calculations (potential point sources of contamination) and 3) classification of land cover from remotely sensed data and NDVI. In this paper RF method is used to estimate the Malekan Aquifer vulnerability, with four sets of data, including A model with all variables, B model with variables related to characteristics of the aquifer, C model with driving forces variables, and D model with variables related to the DRASTIC method. In order to set the value of k from which the error converges and which also makes estimation more reliable, models made up of 1000 trees were generated from all explanatory variables. The parameter was optimized by varying the number of split variables between 1 and the maximum number of variables of every subset. The resulting models were evaluated using the OOB error estimation. For the selection of the most accurate model the one in which the OOB error was the lowest is determined. Moreover, with the aim of reducing the dimensionality and improve the accuracy and interpretability of models, a FS strategy was adopted. The most significant predictive features were selected by using the importance measures of RF. The least significant explanatory variables of every subset were reduced until reaching the minimum error rate. Nitrate concentration was rescaled to a new response variable for every experimental sample: samples with nitrate concentrations higher or equal to the threshold value were given a value equal to 1 and samples lower to the threshold a value equal to 0. The explanative variables (predictors) and response variable were combined together into a set of input feature vectors. These vectors formed the input to the RF algorithm and are known as input-feature vectors. The binary response variable (nitrate pollution) was used as target values for the training of the algorithm. In this study, which four models were used to predict nitrate contamination of groundwater, as shown in Fig2, A and B Models, respectively with RMSE equal to 0/11157 and 0/12214, predicted approximately 44 and 42 percent of the region's in the high vulnerability that located In the central and eastern parts of the aquifer. However C and D models, respectively with RMSE equal to 0/1392 and 0/1597, predicted approximately 15 and 24 percent of the region's in the high vulnerability and could not be trusted in assessment of Groundwater vulnerability.
    Fig 2. Vulnerability Map of the four models. A) All variables, B) variables related to characteristics of the aquifer, C) driving forces variables, and D) variables related to the DRASTIC
    Keywords: Groundwater, Malekan plain, Nitrate, Vulnerability, Random Forest
  • Manouchehr Tabibian, Farideh Ghani* Pages 943-964
    Introduction
    New urbanization evolution in the world and emergence of new urban problems make downtown areas in adverse effects of urban development more than other urban areas. In the third world cities, due to rapid urban growth, influx of immigrants, lack of planning, etc... Problems of downtowns appear more sever which sometimes pose a national issue. The old neighborhoods not only are considered as the memorial of culture and city history but also as an investment which can meet present and future needs of residents.
    This attitude towards old neighborhoods, assume that these areas have abilities and potentials such as infrastructure, vacant land and abandoned building which have the capacity of reuse and redevelopment. As a result, planning for redevelopment of these areas is essential case in most cities.
    Infill development can be associated with development of urban centers, where such projects are used to restore city center neighborhoods. In fact infill development could be proposed as a response to sprawl, a process which makes urban centers remain stunt and away from urban development.
    The first step towards infill development is finding a method to measure development capacity, so using an appropriate approach to evaluate the development potential is essential. One of the references in measuring development potential is Solimar research group which analyze and evaluate infill potential development broadly.
    The question that study is formed around is: "Does the capacity development measurement in Tehran’s city center reflects that it has lands with redevelopment potential?" This study is aimed to evaluate infill development potential in Tehran’s city center. This evaluation is based on criteria which derived from theoretical and empirical literature on subject. After introducing infill development’s indicators, it’s time to evaluate theme in region 12. To achieve this issue by using Geographic Information System (GIS), prepare layers of indicators, overlaying criteria layers, then by using analytical hierarchy process gives priority to divisions of region 12.
    The results indicate that all six division of the region 12 have capacity of development and among these six divisions, division 3, 2 and 4 have the highest rank.
    Materials And Methods
    Research material Region 12 of Tehran city including historical core of Tehran. Center of Tehran as a focus of city, and center of trading, business, aggregation of social, cultural, religious activities is referred as correlation core.
    Tehran’s city center‘s area is about 1600 hectares. Region 12 consist of 6 divisions and 23 neighborhoods. 27 percent of this region has 400-year history and 73 percent of that has over 200-year history. Despite these values, over one third of this area is depressed and out of work. In fact the historical center of Tehran is increasingly vulnerable and in a process of deterioration.
    Research
    Method
    The method of research is descriptive, and data collection method is document review and library studies. Document review and library studies include surveying data, books, journals, articles, urban plans etc. … Data collection resulting in research theoretical frame work and deriving research indicators which are used in development capacity assessment.
    Geographic Information system (GIS), Microsoft Excel, Analytical Hierarchy Process and Expert Choice are used in analytical section for analyzing quantitative indicators of research.
    Discussion of
    Results
    .Population density criteria: Low population density has a high potential for development. Among the divisions of region 12, division 1 and 2 have the lowest population density in the area. Dominant land use of these two division is business zone. Due to dominant use and lower rate of residential use in these divisions, population density is the lowest among the divisions.
    . Land Criteria: Land criteria include three indicators: vacant land, abandoned area and brown field. In city center of Tehran vacant land include around 56 hectares, abandoned area 46 hectares and brown field around 160hectares, and the most concentration of these three indicators are in the division 3.
    . Building Criteria: This criteria include two indicators: quality of building and floors of building. Quality of building, include buildings and lands which encompass destructive structures. Among these 6 divisions in region 12 of Tehran, division 3 has the most areas with low quality of buildings.
    Floors of buildings used as an indicator in assessment of development capacity. Low story Buildings can be considered as a development potential. Tehran city center unlike other downtowns around the world has a very low height. This suggest that Tehran’s downtown has great potential in terms of development density.
    . Access to public transportation criteria: Access to public transportation is a basic feature of a successful infill development. So blocks and parcels with convenient access to public transportation are considered as a potential development. Access to public transportation criteria has two indicators: access to bus stations and access to metro stations. Assessing these two indicators represent that approximately most of the area has an appropriate access to public transportation stations.
    . Regulatory criteria: This criteria is covering five indicators: redevelopment lands, stagnant areas, high density zones, residential zones, mixed-use zones. These five categories are mentioned and determined in Tehran comprehensive plan and region 12 detailed plan, and in this study, they are used as development capacity. In region 12, 9 parcels with 33 hectares area allocated to redevelopment land. In this category, division 4 has the most concentration of redevelopment lands.
    The total area of stagnant area in region 12, is about 641 hectares and division 3 has the most stagnant area in the city center of Tehran.
    According to master plan and detailed plan zoning, about 574 hectares is allocated to high density construction. Due to historic characteristic of division 2 and 3, in order to preserve and maintain valuable building, lack of high density zoning in these two division is acceptable.
    Residential development is a main element of infill development which cause revitalizing and returning population to city centers. Among these 6 divisions, division 5 and 6 have the most potential of residential development in the region.
    Mixed use development is a principle of infill development in order to enhance livability of neighborhoods. Division 1 has the most potential of mixed use development in city center of Tehran.
    After preparing layers of criteria and indicators and overlaying them, it’s time to ranking these 6 divisions to find out which of them has the most capacity of development in the area. Using Analytical Hierarchy Process through Expert Choice software showed that among 6 division of region 12, division 3, 4 and 2 have the highest potential for development.
    Conclusion
    In this study, surveying and analyzing infill development criteria and indicators in city center of Tehran represent these
    Results
    . Population criteria shows that region 12 has a low population density so this area has a potential to attract population.
    . Surveying land and building criteria indicate that the city center of Tehran have areas with capacity of development, also it reflects high dysfunction and deficiencies in the region 12.
    . Access to public transportation criteria indicates that the whole region has the appropriate and convenient access to public transportation.
    . Surveying and analyzing urban plan regulations shows that these regulations not only act as a deterrent to development but also they include development capacity.
    . Assessing and evaluating development capacity in region 12 indicate that all divisions have five introduced criteria but in different proportions. And ranking results showed that division 3 has the highest capacity of development among 6 divisions.
    Keywords: infill development, city center, evaluating development capacity, Geographic Information System