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محیط شناسی - سال چهل و سوم شماره 1 (پیاپی 81، بهار 1396)

فصلنامه محیط شناسی
سال چهل و سوم شماره 1 (پیاپی 81، بهار 1396)

  • تاریخ انتشار: 1396/03/28
  • تعداد عناوین: 12
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  • مقاله پژوهشی
  • حسن سجادزاده *، محمدسعید ایزدی، محمدرضا حقی صفحات 1-15
    علی رغم تمام تلاش ها برای ساماندهی و ارتقاء کیفیت محیطی سکونتگاه های غیررسمی، همچنان برخی مولفه های کلیدی در بررسی ها و تحلیل مسائل این سکونتگاه ها مغفول مانده اند که از آن جمله می توان به تحلیل پیکره بندی فضایی این محلات اشاره کرد. از همین رو برای اثبات فرضیه پژوهش مبنی بر وجود تفاوت های آشکار در پیکره بندی فضایی محلات غیررسمی، به مقایسه برخی پارامترهای پیکره بندی فضایی پنج مورد از سکونتگاه های غیررسمی شهر همدان پرداخته شده است. روش پژوهش حاضر تحلیلی- تفسیری است که در آن سعی شده با تهیه نقشه های همپیوندی، عمق، اتصال و غیره برای چند نمونه موردی به مقایسه و تحلیل پیکره بندی فضایی آنها پرداخته شود. بنابراین پس از بررسی منابع داخلی و خارجی مرتبط با دو موضوع «پیکره بندی فضایی» و «سکونتگاه-های غیررسمی»، نقشه ها و داده های مرتبط با پارامترهای پیکره بندی فضایی شهر و محلات غیررسمی همدان با استفاده از نرم افزار Depth Map تهیه و استخراج شده است. سپس مقایسه کمی و کیفی پارامترهای پیکره بندی فضایی در نمونه های موردی انجام گرفته است. نتیجه بررسی ها نشان می دهد نه تنها تقریبا همه محلات غیررسمی شرایط نامناسبی به لحاظ پیکره بندی فضایی دارند بلکه در پارامترهای آن نیز هر یک از محلات شرایط و خصوصیات متفاوتی دارند و لذا راهبردهای پیشنهادی متفاوتی را طلب می کنند.
    کلیدواژگان: سکونتگاه های غیررسمی، بازآفرینی شهری، چیدمان فضا، کیفیت محیطی، همدان
  • رویا کرمی دارابخانی*، سید یوسف حجازی، سید محمود حسینی، عبدالمطلب رضایی صفحات 17-30
    در طول دهه های اخیر، بروز و افزایش بحران های مختلف زیست محیطی، نگرانی های فزاینده ای را نسبت به امنیت زیستی انسان برانگیخته است. بسیاری بر این باورند که راه حل بحران های زیست محیطی باید در تغییر رفتار و نگرش انسان و روش زندگی وی بر کره خاکی، جستجو شود و تاکنون متغیرهای مختلفی به عنوان عوامل موثر بر تبیین رفتارهای زیست محیطی مورد بررسی قرار گرفته اند. پژوهش حاضر با هدف بررسی تاثیر مولفه های دانش زیست محیطی، ادراک زیست محیطی، نگرش زیست محیطی و نیت زیست محیطی بر رفتارهای زیست محیطی اعضای سازمان های مردم نهاد زیست محیطی انجام شده است. جامعه آماری تحقیق، سازمان های مردم نهاد زیست محیطی استان تهران می باشند که 148 نفر به عنوان اعضای نمونه تعیین شدند. ابزار جمع آوری داده ها پرسشنامه انتخاب گردید که پایایی آن از طریق آزمون آلفای کرونباخ 88 %درصد بدست آمد. نتایج بدست آمده از مدلسازی معادلات ساختاری مبتنی بر روش حداقل مربعات جزیی بیانگر رابطه مثبت و معنی دار چهار مولفه دانش زیست محیطی، ادراک زیست محیطی ، نگرش زیست محیطی و نیت زیست محیطی با رفتارهای زیست محیطی بودند. همچنین نیت به عنوان متغیر میانجی 6/59درصد و چهار متغیر (دانش، ادراک، نگرش و نیت زیست محیطی) 4/33 درصد از مجموع واریانس رفتار زیست محیطی در بین اعضا سازمان های مردم نهاد زیست محیطی استان تهران را تبیین می کنند.
    کلیدواژگان: دانش زیست محیطی، نگرش زیست محیطی، رفتار زیست محیطی، حفاظت محیط زیست، سازمان های مردم نهاد
  • عالیه سیفی، مهدیه حسینجانی زاده*، حجت الله رنجبر، مهدی هنرمند صفحات 31-43
    زهاب اسیدی اثرات مخربی بر محیط زیست دارد. معدن دره زار یکی از معادن مس پورفیری است که دگرسانی فیلیک در آن گسترش قابل توجهی دارد و کانی پیریت (سولفید آهن) در این دگرسانی جزو کانی های باطله با قابلیت تشکیل زهاب اسیدی است. در این تحقیق، کانی های ثانویه آهن مرتبط با زهاب اسیدی در معدن دره زار با استفاده از بررسی ویژگی های طیفی کانی ها و پردازش تصاویر لندست 8 مطالعه و بارزسازی شده اند. به منظور شناسایی ویژگی های طیفی کانی های شاخص زهاب اسیدی از طیف های کتابخانه طیفی USGS1 و برای بارزسازی مناطق دارای پتانسیل زهاب اسیدی با تصویر لندست 8 از روش آنالیز مولفه اصلی استفاده شده است. نتایج نشان دادند که با مطالعات طیفی و روش های پردازش تصویر مانند آنالیز مولفه اصلی امکان شناسایی کانی های زهاب اسیدی وجود دارد با مطالعات میدانی حضور کانی های ثانویه آهن در دامپ های شرقی، غربی و بخش مرکزی توده معدنی تائید شد و در مطالعات طیف سنجی نمونه های صحرایی نیز کانی های ثانویه آهن مانند گوتیت، ژاروسیت و هماتیت شناسایی شدند. اندازه گیری pH و EC وجود آبهای با pH پایین و EC بالا را در محدوده داخل معدن نشان دادند که در مجموع مطالعات میدانی و آزمایشگاهی با نتایج پردازش تصویر هماهنگ بودند.
    کلیدواژگان: پردازش تصویر، دره زار، زهاب اسیدی، لندست 8، ویژگی طیفی
  • مازیار نادری *، ویدا پاست، محمد باقر میران زاده، امیر حسین محوی صفحات 45-57
    امروزه در سراسر دنیا آلودگی آب های طبیعی به آرسنیک به یک مشکل زیست محیطی مهم تبدیل شده است. هدف از انجام این مطالعه بررسی دامنه ی تاثیر میدان مغناطیسی بر روی میزان حذف آرسنیک سه ظرفیتی (آرسنیت) از نمونه های آب آلوده در حضور و یا عدم حضور براده های آهن بود.این مطالعه از نوع مداخله ای می باشد. جامعه ی آماری شامل نمونه ها ی دارای غلظت آرسنیک 2 و 5/0 میلی گرم بر لیتر واکنش داده شده با براده ی آهن در دوز های 0 ، 5 و 5/2 گرم بر لیتر در زمان های تماس 5 ، 10 و 15 دقیقه در pH خنثی و در شرایط آزمایشگاهی بود که با سه مرتبه تکرار آزمایش 108 نمونه بدست آمد. جهت بررسی تاثیر میدان مغناطیسی بر روی یون ها و نمک های تشکیل شده یک ستون مگنتیک طراحی شد و نمونه ها از آن عبور داده شدند. نتایج این مطالعه نشان داد که میدان مغناطیسی غلظت آرسنیک نمونه ها ی بدون براده ی آهن را کاهش ولی غلظت آرسنیک نمونه های دارای براده ی آهن را افزایش داد. از این تحقیق چنین نتیجه گیری می شود که با اعمال میدان مغناطیسی خارجی می توان آرسنیک را بدون واکنش با یون یا جاذب دیگری از آب آشامیدنی حذف کرد.
    کلیدواژگان: آرسنیت، براده های آهن، میدان مغناطیسی، ستون مگنتیک
  • رضا قاسم زاده، مریم پازکی*، حسن هویدی، رمضان حیدری صفحات 59-71
    در این مطالعه به بررسی فرآیند گازی سازی هیدروترمال پسماند تولیدی کارخانه های کاغذسازی موجود در ایران پرداخته شده است. در این تحقیق ابتدا مشخصات یک نمونه پسماند تولیدی کارخانه کاغذسازی مشخص شده است و تمرکز بر اثر دما بر فرآیند گازی سازی هیدروترمال به عنوان یک روش تولید انرژی و یک روش مدیریت پسماند، مورد ارزیابی قرار گرفته است. به منظور تهیه نمونه ای از پسماند کارخانه کاغذسازی که بتواند تا حد ممکن به نمونه واقعی نزدیک باشد، نمونه برداری از پسماند کارخانه کاغذسازی در طول یک سال و در چهار نوبت و از 5 کارخانه کاغذسازی انجام شده است. رطوبت، مواد فرار، کربن ثابت و خاکستر نمونه خشک شده قبل از اینکه ورود به راکتور اندازه گیری گردید. نتایج نشان داد، میزان گاز خروجی مستقیما با دما در ارتباط می باشد و با افزایش دما میزان گاز خروجی افزایش یافت. با افزایش دما از oC 500 به 750 میزان گاز خروجی از میزان 27.09 به 45.22 mol/kg افزایش یافت. میزان CO2 در ابتدا mol/kg 38/8 می باشد که در نهایت به mol/kg 21/17 افزایش می یابد. میزان افزایش در بازه ی 600 تا 650 درجه ی سانتی گراد افزایش ناگهانی دارد که بر اثر واکنش های انجام شده مربوط به تولید CO2 می باشد،
    کلیدواژگان: گازی سازی، هیدروترمال پسماند، کارخانه های کاغذسازی، پسماند، دما
  • منصوره بایرام، امید بهمنی* صفحات 73-86
    خاکهای رسی در محل های دفن زباله به صورت متراکم و به منظور کاهش آلودگی کاربرد دارند. با توجه به اینکه غالبا لاینرهای رسی متراکم غیراشباع می باشند، تخمین ویژگی های هیدرولیکی غیراشباع از جمله منحنی رطوبتی ضروری است. در این پژوهش، منحنی مشخصه رطوبتی(SWCC) خاک رسی در شرایط رطوبتی متفاوت (خشک، بهینه، مرطوب) و تراکم های متفاوت(کاهش، استاندارد، اصلاح شده) با استفاده از دستگاه صفحات فشاری به دست آمد. سپس از 5 مدل تانی، نمایی، روسو، فردلاند و زینگ پنج پارامتره، ون گنوختن برای تخمین Swcc استفاده شد و پس از انتخاب بهترین مدل، پارامترهای آنها به منظور بررسی رفتار خاک رسی مورد بررسی قرار گرفت. نتایج نشان داد که مدل ون گنوختن در نمونه دست نخورده و تراکم کاهشی- بهینه ؛ مدل روسو در تراکم اصلاح شده- مرطوب و مدل فردلاند و زینگ در سایر نمونه ها به دلیل R2 بزرگ تر و SSR و RMSE کوچک تر بهترین عملکرد را ارائه دادند و مدل تانی ضعیفترین عملکرد را داشت. مقدار α در مدل فردلاند و زینگ و ون گنوختن در تراکم اصلاح شده و استاندارد با افزایش رطوبت، افزایش یافت در حالی که در تراکم کاهشی روندی متفاوت داشت. همچنین مقدار α در تراکم اصلاح شده با افزایش رطوبت به مقدار ثابت میل کرد.
    کلیدواژگان: خاک رسی، تراکم، رطوبت، دستگاه صفحات فشار، پارامترهای ثابت
  • آرمان نادری، محمد امیر دلاور *، بابک کبودین صفحات 87-100
    هدف از این پژوهش ارزیابی مدل های خطی و الگوریتم های تکاملی در تهیه نقشه پراکنش فلزات سنگین سرب، روی، کادمیم و مس با استفاده از تکنیک سنجش از دور در اطراف شرکت ملی سرب و روی استان زنجان است. در این پژوهش پیش بینی پراکنش فلزات سنگین با استفاده از اطلاعات تصاویر ماهواره ای سنجنده TM و مدل های رگرسیون چندمتغیره خطی گام به گام و مدل هیبریدی شبکه عصبی مصنوعی-الگوریتم ژنتیک انجام شد. مجذور میانگین مربعات خطا داده های آموزش مدل های شبکه عصبی مصنوعی-الگوریتم ژنتیک برای غلظت کل عناصر سرب، روی، کادمیم و مس به ترتیب 07/0، 09/0، 17/0 و 17/0 و با استفاده از مدل رگرسیون چندمتغیره خطی گام به گام به ترتیب 45/0، 32/0، 48/0 و 54/0 بود. ضرایب تبیین داده های آموزشی در مدل شبکه عصبی مصنوعی-الگوریتم ژنتیک برای عناصر فوق به ترتیب 88/0، 80/0، 75/0، 45/0 و در مدل رگرسیون چندمتغیره خطی گام به گام به ترتیب 53/0، 43/0، 44/0 و 43/0 بود. نتایج تحلیل خودهمبستگی فضایی نشان داد که فلزات سرب و کادمیم خوشه های متمرکزی در اطراف تاسیسات صنعتی داشته و برای عنصر روی بیشتر در اطراف آبراهه های موجود در منطقه تمرکز وجود دارد. نتایج موید پیش بینی موفق کاربرد مدل شبکه عصبی مصنوعی-الگوریتم ژنتیک در تعیین الگوی پراکنش عناصر سنگین با استفاده از داده های سنجش از دور بود.
    کلیدواژگان: آلودگی خاک، تغییرات مکانی، شاخص موران محلی، شبکه عصبی مصنوعی - الگوریتم ژنتیک
  • سپیده عمرانی*، محمد علی دری صفحات 101-115
    نیترات و فسفات مواد مغذی محدودکننده تولید اولیه و موثر بر یوتریفیکاسیون هستند. به همین دلیل اثرات آن ها در شش ایستگاه از تالاب بین المللی گمیشان و یک ایستگاه دریا مطالعه شد. برخی پارامترهای محیطی در محل توسط دستگاه مولتی پارامتر و مواد مغذی توسط اسپکتروفتومتر در آزمایشگاه سنجیده شدند. مقدار جذب فاکتور کلروفیلa، پس از فیلتراسیون (45/0G/FF،) و استخراج در استون90% ، در اسپکتروفتومتر به دست آمد. نتایج نشان داد، عمق کم تالاب موجب بارگذاری فسفر به ویژه در 3s و 4s بود که تحت تاثیر فاضلاب و کود کشاورزی بودند. هر چند عوامل اقلیمی به عنوان عوامل اولیه خشک سالی در منطقه مطرح هستند اما تغییرات کاربری زمین نیز بر میزان تولید رواناب و خشک سالی هیدرولوژیکی موثر بودند. کدورت در ایستگاه دریای خزر و دهانه گرگان رود بالا بود که با کاهش آن طی دوره مطالعه نرخ دسترس پذیری ارتوفسفات افزایش یافت. بعلاوه، در این دو ایستگاه ، نیترات نقش محدودکننده تر داشت. در سایر ایستگاه های مطالعاتی، همبستگی مثبت بین کدورت، کلروفیل a و ارتوفسفات وجود داشت و همبستگی پیرسون در تایید آن، ارتباط معنی دار ارتوفسفات وChla log را نشان داد (**69/0). بر اساس نتایج، اقدامات حفاظتی، پایش دوره ای وکنترل بارگذاری مواد مغذی، در کاهش یوتریفیکاسیون در تالاب بین المللی گمیشان ضروری است.
    کلیدواژگان: ارتوفسفات، بارگذاری، تالاب بین المللی گمیشان، کلروفیل a، نیترات
  • مسعود تابش*، اکبر شیرزاد، قاسم کاظم نژاد سنگرودی صفحات 117-134
    آب از ضروری ترین عوامل توسعه انسانی بوده و ایران نیز ازجمله کشورهایی است که برای تامین آب در مصارف مختلف، به خصوص آب آشامیدنی، دچار مشکل بوده و این مسئله از مهم ترین دغدغه های دولتمردان در راستای توسعه پایدار بوده است. از طرفی تجهیزات، انرژی و مواد شیمیایی مصرف شده در تهیه آب آشامیدنی، اثرات زیست محیطی ای در پی دارند که تشدید گرمایش جهانی به دلیل افزایش گازهای گلخانه ای، از جمله ی این آثار است. لذا در این پژوهش میزان گاز دی اکسید کربن معادل که عامل اصلی گرمایش جهانی است، با ابزار زیست محیطی ارزیابی چرخه حیات و با استفاده از نرم افزار SimaPro در چرخه ی آب آشامیدنی تخمین زده شده است. برای این کار شهر ساری به عنوان مطالعه موردی انتخاب شده و تامین آب از چاه های آب و همچنین در سه سناریو، جایگزینی منابع آب زیرزمینی با آب سد شهید رجایی بررسی شده است. طبق نتایج بدست آمده چنانچه تامین آب از محل سد شهید رجایی انجام پذیرد، میزان اثرات زیست محیطی (مقدار دی اکسید کربن معادل تولید شده) به مقدار زیادی کاهش می یابد. همچنین در بین مراحل چرخه ی آب آشامیدنی، برداشت آب بیشترین تاثیر در تولید گاز دی اکسید کربن معادل را دارد. از بین عوامل موثر در تولید گاز دی اکسید کربن نیز، مصرف برق بیشترین تاثیر را داشته است.
    کلیدواژگان: ارزیابی چرخه حیات، سامانه آب و فاضلاب شهری، چرخه آب آشامیدنی، گازهای گلخانه ای، نرم افزار SimaPro
  • ساناز فتحی، روشنک رضایی کلانتری*، علیمراد رشیدی، عبدالرضا کرباسی صفحات 135-148
    جهت تصفیه آب و حذف فلزات سنگینی چون کروم شش ظرفیتی نانو گرافن متخلخل سنتز شده توسط کربوکسیل عاملدار و سپس بوسیله نانو ذرات Fe3O4 و Fe2O3 مگنت گردید (NPG/Fe3O4@COOH). مغناطیسی کردن جاذب برای کاهش اثرات نامطلوب نانو ذرات مگنت شده و جداسازی از محلول های آبی انجام شده که این فرآیند با استفاده از یک آهنربا به راحتی، در کمترین زمان و هزینه صورت گرفت. مورفولوژی و سایر مشخصات جاذب با استفاده از تکنیکهایSEM، TEM و FT-IRتعیین گردید. اثر پارامترهای مختلف همچون pHمحلول، زمان جذب، دز جاذب، دما و غلظت اولیه کروم در روند کاهش غلظت آلاینده مورد بررسی و مقادیر بهینه هر کدام از فاکتورها مشخص شد. ایزوترم های جذب با استفاده از دو مدل ایزوترم لانگمایر و فروندلیچ و معادلات سینتیکی شبه درجه اول و دوم مورد بررسی قرار گرفت.که نتایج بدست آمده نشان دهنده همخوان بودن میزان جذب با مدل ایزوترم لانگمایر و معادله سینتیکی شبه درجه دوم می باشد. فرایند جذب با افزایش بی نظمی همراه بوده و گرماگیر می باشد. نانو جاذب سنتز شده بدلیل جداسازی راحت و سریع از محلول می تواند به عنوان یک جاذب موثر برای حذف آلاینده ها بویژه فلزات سنگین از آب و فاضلاب در صنعت به کار رود.
    کلیدواژگان: فلزات سنگین، جذب سطحی، ترمودینامیک، ایزوترم
  • حجت الله علی بیگی، روح الله میرزایی*، رسول زمانی احمد محمودی صفحات 149-161
    آلودگی فلزات سنگین یکی از جدی ترین مسائل زیست محیطی در محیط های آبی است. تالاب چغاخور یکی از مناطق مهم بین المللی برای پرندگان است. به منظور تعیین آلودگی ناشی از فلزات در تالاب، غلظت فلزات آهن، روی، مس، منگنز و نیکل در 52 نمونه رسوب سطحی سنجش شد. شاخص های فاکتور آلودگی، غنی-شدگی و زمین انباشتگی به منظور برآورد میزان آلودگی رسوبات مورداستفاده قرار گرفتند. همچنین روش وزن دهی معکوس فاصله برای تهیه نقشه پهنه بندی فلزات در رسوبات استفاده گردید. نتایج نشان داد که غلظت متوسط مس، آهن، منگنز، نیکل و روی در رسوبات به ترتیب 75/15، 86/6076، 74/297، 07/30 و 87/29 میلی گرم بر کیلوگرم بود. با توجه به نتایج حاصل از فاکتور آلودگی، زمین انباشتگی و غنی شدگی، آلودگی قابل توجه و شدیدی از فلزات در رسوبات منطقه مشاهده نشد. بر اساس دستورالعمل کیفیت رسوبات، مشخص شد که تنها غلظت نیکل در رسوبات ممکن است اثر بیولوژیکی نامطلوب بر موجودات آبزی تالاب داشته باشد. اگرچه، نتایج حاصل از تحلیل مولفه های اصلی نیز نشان داد که تمام فلزات عمدتا دارای منشا طبیعی هستند؛ اما الگوی مکانی غلظت فلزات در رسوبات چند لکه داغ را در تالاب نشان داد که به نظر می رسد فعالیت های کشاورزی ، فاضلاب های روستایی، صیادی و گردشگری از دلایل اصلی افزایش غلظت فلزات در این مناطق بوده اند.
    کلیدواژگان: فلز سمی، رسوب، شاخص آلودگی خاک، پهنه بندی، تالاب چغاخور
  • مصطفی فرهادیان*، امید بزرگ حداد، مریم پازکی، سمانه سیف اللهی آغمیونی صفحات 163-180
    برای تامین جریان زیست محیطی رودخانه می توان بخشی از جریان های تخصیص یافته به دیگر اهداف بهره برداری از سدها مانند صنعت، برق آبی و کشاورزی را به جریان زیست محیطی اختصاص داد. اما برای ایجاد یک تعادل مناسب و رعایت عدالت در میان ذی نفعان اهداف زیست محیطی و دیگر اهداف موجود، لازم است تمامی این اهداف به منظور تعیین یک جریان رهاسازی مناسب، به طور هم زمان مورد بررسی قرار گیرند. بنابراین در این تحقیق، به تعیین جریان رهاسازی بهینه از سد به گونه ای که این جریان بتواند تمامی اهداف کلان موجود در بهره برداری از آب رودخانه را تامین کند، پرداخته شده است. برای تعیین جریان رهاسازی بهینه، مقدارهای جریان زیست محیطی در رودخانه با استفاده از روش های هیدرولوژیکی محاسبه شدند. سپس اهداف کمی و کیفی موجود در بهره برداری از آب رودخانه، شناسایی، دسته بندی و تعریف شدند. پس از آن، با استفاده از نظریه حل اختلاف نش، از میان بازه جریان زیست محیطی حاصل شده، یک جریان رهاسازی بهینه با توجه به تمامی اهداف مختلف موجود، تعیین شد. روش ارائه شده بر روی سامانه مخزن-رودخانه گتوند-کارون به-کار گرفته شد و جریان رهاسازی بهینه برای وزن های نسبی مساوی برای تمام اهداف، برابر با 8/183مترمکعب بر ثانیه به دست آمد.
    کلیدواژگان: جریان رهاسازی، جریان زیست محیطی، کنترل کیفیت آب، حل اختلاف، سامانه گتوند - کارون
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  • Hasan Sajjadzadeh *, Mohammad Saeid Izadi, Mohammadreza Haghi Pages 1-15
    IntroductionAttention to the city structure have been influenced since structuralism viewpoint from the early 1960s. At the beginning of the 1960s, Team Ten tried to consider the city like the whole unite, in contrast to the functionalism. In this viewpoint, theorists such as Edmund Bacon, Christopher Alexander and Kevin Lynch have underscored the importance of urban open spaces; streets structure have created most area of them as the most important element of spatial structure that it can enhance connections between space and people. After that at the ending of 1970s, Bill Hillier and Joseph Hinson produced the Space Syntax theory for the cognition of spatial structure and urban configuration. They examined the relationship between space configuration and special behaviors.
    The mean of space configuration is the condition of spaces next to each other and makes connection between them. Thus it can be concluded that each change on the arrangement of spaces will create changes in the whole of spatial configuration. In other words, in the city, each change on the city map (add or subtract a space such as streets, open space, etc.) will create changes on the relation of spatial configuration. These changes can vary the probability of activities and events. Recently, it has been proposed to improve the living conditions of residents of informal settlements however, it has not achieved the planned goals. One of the reasons for this problem is inattention to importance of knowing neighborhoods in various aspects of economic, social and physical ones.
    This study has tried to survey and analyze the different parameters of spatial configuration for a number of informal settlements of Hamedan through which we can identify the differences between neighborhood structures.
    Materials & MethodsThis study has been done using Analytical-Interpretive method, library research, and spatial configuration analysis of several case studies. At the beginning, the literature review was obtained through library research.
    The next step, for analyzing the spatial configuration of neighborhood, we produced the map of urban blocks. This map separates full and empty spaces (streets and squares) from each other. After that, linear map is drawn for the city using the software of Depth Map. Then, various parameters of spatial configuration (including Line Length, Integration, Depth, Connectivity, Control and Choice) are extracted by linear map of city. Finally, based on analyzing the various parameters, key strategies are suggested for improving the spatial configuration of case studies.
    Discussion and ResultsIn this study, the linear map of Hamedan has been drawn using the software of Depth Map. The linear map is included structure of a series of urban open spaces that they have been created based on the longest view line and connection. After drawing linear map of the city, the parameters of spatial configuration can be extracted for informal settlement. The main parameters of analyzing spatial configuration are included Line Length, General Integration, Local Integration, Depth, Connectivity, Control and Choice that their characteristics for case studies are as follows:Hesar Neighborhood:• The suitable situation in General Integration
    • The lowest Local Integration
    • The lowest average of Connectivity
    • The highest average and standard deviation of Choice
    • The suitable situation in Depth
    Khezr Neighborhood:• The lowest average of Line Length like the Dizaj neighborhood
    • The suitable situation in General Integration
    • The highest average of Connectivity
    • The lowest average and standard deviation of Choise
    Dizaj Neighborhood:• The lowest average of Line Length
    • The lowest average of General Integration
    • The highest average and standard deviation of Local Integration
    • The highest average and standard deviation of Depth
    Mazdaghineh Neighborhood:• The lowest average of Line Length
    • The suitable situation of Local Integration
    • The highest average and standard deviation of Local Integration
    • The suitable situation of Depth
    • The highest average of Connectivity
    • The lowest standard deviation of Control
    • The lowest average and standard deviation of Choice
    Manouchehri Neighborhood:• The highest average of Line Length
    • The highest standard deviation of Line Length
    • The highest average of General Integration
    • The lowest average of Connectivity
    • The highest standard deviation of Control
    • The lowest average and standard deviation of Depth
    ConclusionAccording to parameters of spatial configuration (Line Length, Integration, Depth, Connectivity, Control, and Choice) in Hamedan and five informal settlements (Hesar, Khezr, Dizaj, Mazdaghineh and Manouchehri), the results showed a significant difference between case studies. However, the situation of spatial configuration of neighborhoods was not satisfactory and it is essential to adjust and organize their spatial configuration parameters.
    The following are some general strategies suggested for improving the spatial configuration of case studies:• Hesar Neighborhood: it is essential to create structure of streets and texture for this neighborhood as a whole unit. Therefore these strategies are suggested: “ promoting unity and solidarity in structure of streets and texture”, “developing the available vacant land in the neighborhood” and “creating some main east-west streets to increase Local Integration and decrease the isolation edges of neighborhood”
    • Khezr Neighborhood: The dense texture and North-South structure of this neighborhood has caused a lot of pressure on the street in western edge. Therefore, the following strategies are suggested: “decreasing dense and massive texture”, “creating the North-South arterial street in the east of neighborhood for decreasing Depth and isolating eastern part of neighborhood” and “strengthening the relationship of neighborhood with ring road in east of neighborhood”
    • Dizaj Neighborhood: the structure and inner configuration of this neighborhood is relatively stable and it seems essential to solve the problem of isolation of overall city. Therefore, these strategies are suggested: “decreasing isolation of neighborhood from the whole of city”, “developing the vacant lands between neighborhood and the city” and “promoting the order of street structure inner the neighborhood”
    • Mazdaghineh neighborhood: This neighborhood has the suitable opportunity in spatial configuration of city, but internal configuration of that is strongly influenced by the rural pattern. Therefore, these strategies are suggested: “organizing and disciplining the inner streets of neighborhood”, “redesigning and aggregating of small blocks” and “creating several cross streets in structure of neighborhood”
    • Manouchehri neighborhood: The spatial configuration of this neighborhood is better than other informal settlements. It can be attributed to raster-like structure and small area. Therefore, these strategies are suggested: “creating a hierarchy of streets by converting some public streets to Semi-public Street” and “decreasing the uniformity of texture through creating a variety of streets and intersections”.
    Keywords: Informal settlements, urban regeneration, space syntax, Environmental Quality, Hamedan
  • Roya Karami Darabkhani * Pages 17-30
    In recent decades, environmental crises have caused increasing concerns about the safety of human life. Many believe to the environmental that the solution crises should be searched in the change of human behavior and attitude’s and his life method on earth. Researchers have suggested various solutions for environmental problems, most of which are technological. But nowadays due to the high cost of these projects, they are interested in changing people's lifestyles and behavior. Different models and theories have been used in various studies to explain the environmental behavior and different variables have been studied as the effective factors on environmental behavior.
    Environmental NGOs have been stablished due to society needs and raising public awareness and knowledge about environmental issues is the main role of NGOs. These organizations play an important role in achieving the goals of protecting the environment, reducing pollution and recovering environmental damages. Therefore Environmental NGOs is one of the most important tools for environment conservation. The main goal of this study is to investigating the effects of environmental knowledge, environmental perception, environmental attitudes and environmental intention on environmental behavior of environmental NGOs members.This study is a descriptive-correlational research and survey method was used to collect the data. The statistical population consisted of environmental NGOs members in Tehran Province which are active in environmental education field that has about 250 main and active members. Sample size determined 148 person by using Krejcie and Morgan table and Sampling was done randomly. In this study in order to collect information, a questionnaire including 55 items in two parts was used: The questions of the first part was about the individual features and the second part questions were related to four factors influencing environmental behavior including environmental knowledge, environmental attitude, environmental perception and environmental intention. Items were designed by adopting new environmental paradigm questionnaire: ýDunlap et al. (2000), environmental knowledge questionnaire: Morrone et al. (2001) and Frick et al. questionnaire (2004). Content validity was confirmed by experts and its reliability Obtained based on Cronbach's alpha α=%88. Data analysis is done by using SPSS 21 and Smart-PLS software. In descriptive statistics mean, standard deviation and coefficient of variation and in inference statistics, structural modeling based on partial least squares approach were used.According to Table 1, the independent variable (environmental attitude), has the most effect on the of mediator variable (environmental intention) and also the most impact on the dependent variable (environmental behavior), and then environmental knowledge is most effective. Environmental intention as mediator variable is explained 59/6 percent of the variance of the environmental behavior between environmental NGOs members in Tehran Province. Also the four variables (environmental knowledge, environmental attitude, environmental perception and environmental intention), 33/4 percent of the variance of the dependent variable: environmental behavior is explained by four variables: environmental knowledge, environmental attitude, environmental perception and environmental intention. And the remaining percentage is related to factors that have not been identified in this research.The results of the research hypotheses testing in Table 5 shows that all hypotheses have been confirmed.
    Result T Value Beta hypotheses
    confirmed 5/429 0/499 Hypothesis 1: There is a significant relationship between knowledge and environmental behavior.
    confirmed 4/876 0/664 Hypothesis 2: There is a significant relationship between attitude and environmental behavior.
    confirmed 5/341 0/445 Hypothesis 3: There is a significant relationship between perception and environmental behavior.
    confirmed 10/518 0/578 Hypothesis 4: There is a significant relationship between intention and environmental behavior.
    confirmed 5/961 0/316 Hypothesis 5: There is a significant relationship between knowledge and environmental intention.
    confirmed 7/002 0/421 Hypothesis 6: There is a significant relationship between attitude and environmental intention.
    confirmed 5/592 0/282 Hypothesis 7: There is a significant relationship between perception and environmental intention.
    The results showed that all four variables (environmental knowledge, environmental attitude, environmental perception and environmental intention), have a high mean in the environmental NGOs members in Tehran Province. Also there is a positive and significant relationship between all four variables (environmental knowledge, environmental attitude, environmental perception and environmental intention) and environmental behavior. Environmental attitude has been identified as the most effective variable on environmental intention and environmental behavior in this study. So, awareness programs should be implemented for changing the attitude of the people and creating a proper environmental behavior culture. To create a positive attitude towards the environment in people, organizational goals should clarify and explain for all members. For this purpose NGOs can use seminars, question and answer sessions and periodically meetings for organization members. environmental education in order to creating positive environmental attitude has to be considered because Having knowledge and understanding about environmental issues are the necessary conditions for good attitudes and impacting on behavior. Environmental education is the most fundamental method for environmental protection that aims to find the most suitable and best systems for Presenting contents and practices and implementation a structural that promote environmental awareness and knowledge and finally creating positive attitude in society and each person feels responsibility to preserve and protect the environment. Experts believe that knowledge, attitudes and perception’s changes of people towards the environment will lead to develop and strengthen environmental behavior and reducing damage to the environment and reforming the environment crisis. One of the most important tools for making changes in effective factors on environmental behaviors, is environmental education. Promoting environmental awareness in the society for each person, create a positive attitude toward environment, feeling responsibility for maintaining and protecting the environment and respect nature and Knowledge about different approaches for environmental problems and participating in finding solutions, all of these are capabilities that can be achieved only with efficient environmental education. One of the important issues about environmental behavior and environmental conservation, is pay attention to environmental NGOs education and training. NGOs according to their mission and objectives, has appropriate facilities to increase public awareness through education and training of their members and other people and should t support these organizations in order to achieving their goals.
    Keywords: Environmental knowledge, Environmental Attitude, Environmental Behavior, Environmental Conservation, NGOs
  • Aliyeh Seifi, Mahdieh Hosseinjanizadeh *, Hojjatolah Ranjbar, Mehdi Honarmand Pages 31-43
    Introduction
    Oxidation of iron sulfide is a common phenomenon in mining areas and sometimes generates acid drainage. Acid drainage is produced under certain conditions of pH and Eh when metallic sulphides (mostly iron) are exposed to oxygen and water. Copiapite (Fe2ᗭ(SO4)6(OH)2•20(H2O)), jarosite ((SO4)2KFe3(OH)6), schwertmannite (Fe3힣(OH)12(SO4)2), goethite (FeO(OH)), ferrihydrite (Fe5HO8.H2O), lepidocrosite (FeO(OH)), and hematite (Fe2O3) minerals are formed by oxidation of pyrite with increasing pH (from very acidic to neutral) and are frequently observed in mining areas with acid drainage pollution.
    Landsat 8 can be used for environmental studies and detection of secondary iron minerals associated with acid drainage, as it has characteristics such as a relatively good temporal (16 days) and spectral resolutions in the visible and infrared (VNIR) ranges. This research focuses on the study secondary iron minerals associated with acid mine drainage using investigation of spectral characteristics of AMD minerals and image processing of Landsat 8 data in the Darrehzar mine.
    Material and
    Method
    Spectra from USGS spectral library and Zabcic (2008) were chosen for identification of spectral characteristics of secondary iron minerals associated with acid drainage such as copiapite, jarosite, schwertmannite, goethite, ferrihydrite, lepidocrosite, and hematite. Furthermore, the resampled spectra of these minerals based on bands’ centers of Landsat 8 were also investigated. Lepidocrosite, ferrihydrite, goethite, and schwertmannite have the same spectrum on the resampled spectrum of USGS spectal library. These minerals are created in acidic to near neutral conditions. Simillarly, jarosite and copiapite which are associated with very acidic conditions, have the same features in the visible range.
    The Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes (FLAASH) correction applied on the images to compensate for the atmospheric effects. The NDVI masking was used to remove vegetation before performing principle component analysis technique. Then selected principal component analysis (PCAs) technique was used for image processing. The ferric iron absorption (Fe3 ) of band 1 at copiapite, jarosite, schwertmannite, goethite, ferrihydrite, lepidocrosite, and hematite (0.433-0.453 micrometers), absorption of band 7 (2.100-2.300 micrometers) for copiapite and jarosite due to SO4 and OH vibrations and reflectance values in band 4 (0.630-0.680 micrometers) for copiapite and jarosite and band 6 (1.560-1.660 micrometers) of Landsat 8 for jarosite, schwertmannite, goethite, ferrihydrite, lepidocrosite, and hematite considered to perform this technique.
    According to the eigenvector loading and spectral characteristics of Schwertmannite, goethite, ferrihydrite, lepidocrosite, and hematite minerals, PC2 is appropriate for discrimination of these minerals as bright pixels due to the high positive loading in band 6 and high negative loading in band 1. Jarosite will be presented by dark pixels in PC3 because of high positive loading in band 7 and high negative loading in band 6 which are absorptive and reflective bands respectivelly. This PC was multiplied by -1 to convert pixels related to Jarosite as bright pixels. Copiapite and jarosite will be presented by bright pixels values in PC4 based on high positive loading in band 4 and high negative loading in band 1 which are reflective and absorptive bands respectivelly.
    Eventually, field survey was conducted for evaluation and verification of results of image processing. The rocks and water samples were taken out of the areas identified by image processing. Five water samples were taken from different parts of the mining area that consist of influx water to the mine (Da31), Piezometer well in the mine (Da32), water pit located in the eastern part of mine (Da23), accumulated water in the western part of mine (Da20), and discharging water from the mine (Da24).
    Water samples were taken by Polyethylene bottles and recorded their temperatures in situ and transferred to Graduate University of Advanced Technology laboratory for EC and pH measurements. Their pH and EC were measured by Metrohm 827 lab pH meter and Metrohm 712 Conductometer EC meter. Rock samples were taken from southern, western, and eastern dumps and in the central part of the mine based on image processing results and transferred to Graduate University of Advanced Technology laboratory for spectroscopy measurments. Spectroscopy of rock samples was conducted by ASD FieldSpec®3. The measured spectra were compared with the spectra in USGS spectral library.
    Result
    Schwertmannite, goethite, ferrihydrite, lepidocrosite, and hematite that have been detected in PC2, were located around the mine and pixels having high values (marked by red colour) have been presented in the east and northwest mine (Fig 1C). Secondary iron minerals such as hematite and goethite were observed on the eastern and western dumps during the field survey. Spectroscopy results were presented goethite and hematite on the western dump and goethite on the eastern dump.
    Jarosite which were detected as bright pixels in -PC3, cover the interior of mine and tailing dumps. Furthermore the bright pixels in –PC3 correspond to argillic and phyllic zones in Darrehzar mine. Pixels having high values (marked by red color) have been observed within and eastern parts of mine (Fig 1B). Copiapite and jarosite have been situated along the main stream in the middle part of the mine and southern dump (Fig 1A).
    EC and pH measurements of water samples determined that the water samples taken from eastern part of mine (Da23) and accumulated water in the western part of mine (Da20) have high EC and low pH while influx and discharging water of the mine have low EC and neutral pH. Water sampling areas having high EC and low pH (Da23 and Da20) conform to copiapite and jarosite in PC4. Despite precence of water with low pH and high EC inside of the mine, discharging water of the mine has low EC and neutral pH. It shows that during the sampling time acidic water inside of mine has no influence on the discharging water because acidic water is preserved in a reservior inside the mine. However, acidic water may be cause pollution during high rainfall period and it should be consider at the management planning of the mine.
    Conclusion
    Investigations spectral features of secondary iron minerals associated with acid mine drainage revealed that strong absorption of the minerals associated with very acidic environments such as copiapite (0.430µm) and jarosite (0.436µm) is located at lower wavelengths than strong absorption of the minerals associated with acidic to neutral environments such as schwertmannite (0.489 µm), goethite (0.480 µm), ferrihydrite (0.489 µm), lepidocrosite (0.480 µm) and hematite (0.480 µm). In addition, jarosite (associated with very acidic conditions) show strong absorption feature in short wave infrared (SWIR) region (2.26µm) due to SO4 and OH vibrations while the other minerals such as schwertmannite, goethite, ferrihydrite, lepidocrosite and hematite do not have any absorption features in this region. The results of spectral processing revealed that despite there are some similarity between schwertmannite, goethite, ferrihydrite, and lepidocrosite; it is possible to discriminate AMD minerals using spectroscopic studies due to large numbers of spectral channel in spectrometers.
    The result of Landsat- 8 image processing showed that the OLI sensor in this satellite could identify secondary iron minerals associated with acid drainage and determine environments having different acidic conditions. However it could not separate hematite, goethite, lepidocrosite, ferrihydrite, and schwertmannite which have relatively the same spectra from each other and also copiapite and jarosite. Based on PCA results lepidocrosite, ferrihydrite, hematite, goethite, and schwertmannite that are associated with acidic to neutral conditions, were detected around mine while copiapite and jarosite that are generated in acidic condition (low pH), have been detected inside mine. Results of laboratory and field analysis conformed image processing results so that spectroscopy analysis on samples of eastern and western dumps revealed hematite and goethite which correspond to discriminated minerals like hematite, goethite, lepidocrosite, ferrihydrite and schwertmannite in PC2.
    Acknowledgment:The authors are sincerely grateful to the geologists and staff of the Sarcheshmeh copper mine especially Mr. Khosrowjerdi, Dr. Sahrayi, and Mr. Salajegheh for providing the facilities and kindly helping us during our field work.
    Keywords: Acid mine drainage, Darrehzar, Image processing, Landsat 8, spectral characteristics
  • Maziar Naderi *, Vida Past, Mohammad Bagher Miranzadeh, Amir Hossein Mahvi Pages 45-57
    IntroductionArsenic is a toxic metalloid and exists in nature in the two organic and mineral forms. Arsenate is the oxidized form and is predominant in the surface waters, while arsenite is a reduced form and is often found in the groundwater. Besides, toxicity and solubility of arsenite is more than that of arsenate. Excessive and prolonged human intake of inorganic arsenic, through drinking water and food, causes arsenicosis, which includes skin disorders, skin cancer, internal organ cancer, arm and leg vascular diseases and diabetes. The World Health Organization (WHO) guideline value for arsenic in drinking water is set as 10 µg/l. It should be noted that this standard is 50 µg/l in Asia and also in Iran. There are three main methods for arsenic removal from drinking water, including membrane filtration, coagulation-precipitation and adsorption. Water treatment by means of the magnetic field has been recently considered. Ma Wei et al. investigated the arsenic removal via sulfide ions in the magnetic field. Stephen and Coey carried out a study on water treatment using the magnetic field. Lipus et al. surveyed the influence of magnetic field on the aragonite precipitation. Also, Ambashta et al. investigated water purification using magnetic assistance. Besides, Ochkov et al. conducted a study on magnetic treatment of water. Gholizadeh et al. investigated the effect of magnetic field on scale prevention in the industrial boilers. Amiri et al. carried out a study on the reduction of the surface tension of water due to magnetic treatment. In addition, Banejad et al. conducted an experiment on the effect of magnetic field on water hardness reducing. In this study, the efficiency of iron filings in arsenite removal from polluted water was primarily surveyed, and then the effect of magnetic field on the process was investigated. The innovation of this research will be to understand the importance of physical forces such as magnetic field in the field of water purification and its application in the water industry.
    Materials and Methods Preparation of AdsorbentThe required iron filings were prepared in the turning workshops of Tehran, Iran. The iron filings were passed through a sieve with pores of 2 mm and were made wet using deionized water, and ferric hydroxide precipitation was allowed to be formed on the surface of the filings.
    Making the Magnetic ColumnA circular magnet with the magnetic field intensity of 0.01 T was primarily placed around a glass column and a iron spiral was located in front of the magnet inside the column, so that the sediments on it could be reacted. (Discharge velocity was 2 mm/s).
    Preparation of the SamplesThe synthetically arsenic-polluted water samples were prepared by diluting 0.1N sodium arsenite solution (Merck) with de-ionized water. In addition, to prevent the oxidation of arsenite to arsenate the required solutions were prepared on a daily basis at 0.5 and 2 mg/l concentrations.
    The TestsThe prepared arsenite solutions at 0.5 and 2 mg/l concentrations were reacted in contact with the iron filings adsorbent at 0, 2.5 and 5 g/l dosages over contact times of 5, 10 and 15 minutes within a beaker with the volume of 100 mL on the shaker at the velocity of 400 rpm. Half of the sample (50 ml) was then passed through the column at the velocity of 2 mm/s and a blank (without iron filings) was considered for each sample. Then, the arsenic concentration of the samples was measured by the ICP system. Moreover, the electrical conductivity of the samples was measured using EC meter. After data collection the arsenic removal efficiency in any state was calculated. Mean and standard deviation of removal efficiencies were determined and the variables were compared with each other by means of paired t-test and one-way ANOVA.
    Discussion of results and conclusions MixingThe results indicated that with the increase of the initial arsenic concentration, the removal efficiency also increased that was due to the oxidation of arsenite into the insoluble arsenate ion. Via analysis of iron filings by extraction with hydrochloric acid, Hsing et al. showed that almost 28% of arsenic has existed in the form of arsenate, which revealed that oxidation has also been effective in arsenic removal.
    Initial Arsenic ConcentrationThe results demonstrated that with the increase of the initial arsenic concentration, the arsenic removal efficiency decreased. Yu Zhang achieved the adsorption capacity of 16 mg/g at the arsenic concentration of 1 mg/l, while Hsing reported the adsorption capacity of 7.5 at the arsenic concentration of 50 mg/l.
    Iron Filings DosageBased on the obtained results, with the increase of the iron filings dosage, the arsenic removal efficiency increased as well. Tyrovola et al. showed that with the increase of the iron filings dose, the removal efficiency of arsenite ion increases.
    Contact TimeThe results showed with the increase of the contact time desorption can occur at various times. In the samples with high arsenic concentration and iron filings, due to ferric hydroxide sites on the iron filings and therefore higher adsorption, the desorption process occurred at longer contact times.
    pHThe iron filings, unlike the other adsorbents, have a high affinity to the reaction with arsenic at the normal pH of water. Ramaswami et al. removed the arsenite by iron fillings at the pH of 7 with the efficiency of 95%.
    The Magnetic FieldThe results showed that the magnetic field reduced the arsenic level of the samples without iron fillings but increased the arsenic level of the samples with iron fillings. The ferric hydroxide ion was formed on the surface of the iron filings.
    Sodium arsenite (NaAsO2) reacts with ferric hydroxide (Fe(OH)3) and forms ferric arsenite (Fe(AsO2)3) on the surface of the iron filings. Also, ferrous hydroxide ion is formed within the solution and can react with sodium arsenite and ferrous arsenite (Fe(AsO2)2) can be thus formed. Based on the physicochemical Hall Effect, when a multi-atomic ion placed within a fluid passes through the external magnetic field, the bond between the ions is weakened and they are dissociated and form cations and anions. When charged particles are placed in a magnetic field a force is applied by the magnetic field to the particle, which is called “Lorentz force”. After the blank or control sample (sodium arsenite) passed through the magnetic field, these two ions were dissociated based on the Hall Effect and finally reacted with the ferric hydroxide formed on the metal spiral. When the ferric arsenite ion passed through the magnetic field, the ions were dissociated and were affected by Lorentz force. Arsenite has one negative charge and ferric has three positive charges and since ferric ion has higher charge, more force is applied to it and it attaches to the spring inside the column. Arsenite was also affected by Lorentz force and reacted with the ferric formed on the spring, but as the dissociation level of ferric arsenite ion was more than its adsorption, the arsenite level in the outlet column increased. Ferric arsenite is insoluble and was not measured by the device. When the solutions were passed through the column, arsenite separated from ferric and changed into a solution which could be measured.
    Electrical Conductivity (EC)The results of this study demonstrated that the magnetic field increased EC. When the ions of a solution are exposed to the magnetic field, they are dissociated and the solution forms more ions and thus EC increases. Ma Wei showed that EC of the samples before and after the magnetic field were 0.22 and 0.27 S/m respectively.
    Based on the results obtained from this study, it can be concluded that by applying a stronger magnetic field around the magnetic column, the arsenic in drinking water can be removed with high efficiency without adding any chemicals or adsorbents.
    Keywords: Arsenite, Iron filings, Magnetic field, Magnetic column
  • Ramezan Heidary, Maryam Pazoki * Pages 59-71
    Hydrothermal process can be divided into three parts. The first part is hydrothermal carbonization aimed at production of hydrochar and is performed in operating temperature range between 180-250 oC. The other subject is Hydrothermal liquefaction which is performed in operating temperature range of 200-370 oC and aimed at production of heavy oil and in the end the last part, which contains super-critical conditions, is named hydrothermal gasification with the purpose of production of flammable gases and this is the matter of the article.
    Overall, about 35% of the input materials to paper mills are in the form of different wastes such as wastes of processing recycled fibers, sludge, waste of water and wastewater purification system and also de-inking sludge part. In the northern regions of Iran, as the necessary conditions for producing paper are available, several paper mills are existed. Now, in order to manage waste of paper mills in northern Iran, the landfilling and burning method is being used, each with their problems. For instance, on one hand landfilling requires an extensive land area and in addition the land value is so high in north of Iran and on the other hand the level of underground waters are high in north of the country and it may get polluted. Incinerators also pollute the air and the burning area and as a result contribute to increase greenhouse gases.
    Materials and MethodsSamples are taken during a year in 2014 at the beginning of each season, in four times and from five paper mills in order to provide a model of paper mill waste which would be the closest to the real model. The sampled waste was gray, with the smell of wet newspaper and containing particles and fibers with dimensions of 1 to 5 mm. pH of the waste sample was close to the neutral pH=7. The moisture content of the paper mill waste was 39% and needed a pre-treatment to prepare for the hydrothermal gasification process.
    Feedstock has been analyzed approximately (proximate analysis) before entering the reactor in order to measure the moisture, volatile substances, fixed carbon and ash of input material entering the reactor. Then, after determining the area under the peak of each of the components, the produced gas is calibrated and converted to mol/lit.
    Results and DiscussionThe amount of output gas is directly related to the temperature and gas production increases when temperature rises. This increased efficiency is probably due to the cracking of heavy hydrocarbons. Another reason could be due to Char endothermic reactions, when conditions become suitable for the development of the reactions with increasing temperature. With enhancing temperature from 500 oC to 750 oC, gas output increases from 27.09 to 45.22 mol/kg. It should be noted that according to the papers in the field of gasification, efficiency improvements in gas production are also being observed in hydrothermal gasification technique. This increase in the volume of the gas begins from 3.034 lit and continues up to 5.064 lit. It means that the amount of the volume has increased of 66.9 % at this temperature range and only under the effect of temperature changes.
    In summary the changes of gas amounts are as below: the amount of CO2 and H2 is enhanced and the amount of CO and CH4 is reduced in whole and it illustrates a more optimized mode compared to the gasification mode without presence of moisture. Because in normal mode (the typical gasification), less hydrogen gas is generated and we can fetch up the result that water enters into this process as a catalyst and reactant helper to produce H2 and facilitates reactions to produce hydrogen as more as possible. In fact water has a role in which more water-gas transfer reactions occur in the presence of water and the conversion rate of water-gas increases with increasing temperature as a result of increasingly breaking carbon bonds.
    Efficiency level of generated gas has been increased like typical gasification. The result was not unexpected because water evaporates due to the temperature enhancement and water presence and it generates more pressure in accordance with higher temperature, then in a high pressure cracking reactions occur in better conditions and materials break more easily. The changes are located in the range of 0.61 to 1.01 (m3/kg).
    In general we can conclude that the amount of generated gas enhances by increasing temperature in hydrothermal gasification and in contrary its heating value rate decreases while carbon conversion rate is increased. As a result in order to achieve the aim of optimizing we need to consider a temperature in which the generated gas amount would be much and in addition its heating value would be high. Here, the acceptable heating value is considered more than 10 and its heating period is considered between 500 °C to 600 °C. In this period, the gas yield rate is placed in the range of 0.61 to 0.77. As we get closer to the temperature of 500 °C, the heating value of the gas coming from the reactor increases.
    ConclusionIn this study, north of Iran’s paper mill wastes was examined and the testing process was hydrothermal gasification process. Wastes from five factories were sampled at the beginning of each season and after pre-treatment phase they were imported into the hydrothermal gasification reactor in the waste to energy laboratory of Environment Faculty of Tehran University. Results from studying waste characteristics before entering hydrothermal gasification process and its output products showed that changes are as below: The amount of CO2 and H2 is enhanced and the amount of CO and CH4 production is reduced in whole and it illustrates a more optimized mode compared to gasification mode without the presence of water.
    Keywords: Gasification, hydrothermal, paper mill, Waste, temperature
  • Omid Bahmani * Pages 73-86
    clay soils in landfills are used as compacted and to reduce contamination. As regards, compacted clay liners are often unsaturated, estimating unsaturated hydraulic properties including soil water characteristic curve is essential. In this study, clay soil water characteristic curve (SWCC) in Various Moisture conditions (dry, Optimum, wet) and different compactions (reduced, standard, modified) were obtained using a pressure plate. Then, the five models of Tani, exponential, Russo, Fredlund and Xing five parameters, Van genuchten were used to estimation Swcc and then select the best model parameters were studied in order to investigate the behavior of clay. The result showed that Van genuchten model in Undisturbed sample and reduced compaction-optimum; Russo model in modified compaction-wet and Fredlund and Xing in other sample due to larger R2 ,smaller SSR and RMSE provided the best performance and Tani provided the weakest performance . Value of α in the models of Fredlund and Xing and Van genuchten in modified and standard compactions increased with increasing Moisture, while in the reduced compaction was different. Value of α in modified compaction with increasing moisture content to be a constant value.
    IntroductionCompacted clay soils are commonly used as barrier materials in waste containment facilities. The selection of these soils as barrier materials is based on their saturated behavior (miller et al, 2002).
    The objective of this study was to estimate SWCC by fitting models of Tani[20], Expotential[13], Russo[21], Fredlund And Xing Five Parameters (Fx5([18], Van Genuchten (VG) [22] and determination parameters of them using matlab software and select the best model and also investigate soil behavior as liner.
    Materials And Methods
    2.1. Soils
    Soils used in the study were obtained from agricultural research center of Hamadan, Iran. Soil samples were obtained from depths of 0 – 30. Particle size distribution (PSD) was determined using hydrometer method, based on Stokes’ Law (ASTM D422) and Then Texture AutoLookup (TAL) software for windows (version 4.2) was used to determine the soil texture class based on United States Department of agriculture textural classification system and soil texture triangle (USDA). Nine disturbed samples (three compaction type under three moisture conditions) and one undisturbed samples were collected from each soil texture. Samples were prepared using three compaction efforts included reduced, standard, and modified compaction efforts. For each compaction effort, samples were prepared at three water content conditions included 2% dry of optimum, optimum and 2% wet of optimum water content.
    2.2. Compaction
    For the standard compaction, the hammer was dropped on the soil in the mold 25 times on each of three soil layers (ASTM D1557). The reduced compaction was similar to standard compaction with one exception; 15 blows/layer were used instead of 25 blows/layer (Daniel and Benson, 1990). The reduced effort was used to simulate poor quality compaction procedures in the field. The Modified compaction, the heavier hammer was also dropped 25 times on each of five soil layers (ASTM D698). Then compaction tests were performed over a range of soil moisture contents. The results were then plotted as dry density versus moisture contents. The maximum dry unit weight occurs at a water content that is called the optimum water content. The maximum dry unit weights and the corresponding optimum water contents were estimated. Compaction characteristics of the soils are presented in Table 2.
    Table 1. Compaction Characteristics of Soil Samples
    Clay Soil
    reduced Standard modified Compaction effort
    13.08 13.91 14.57 Maximum unit weight(KN/m3)
    22.48 16.39 12.46 Optimum water content%
    After calculation the optimum water content, Once again, soil samples were compacted. Then, soil samples were prepared at three compaction effort under three water content conditions included 2% dry of optimum, optimum and 2% wet of optimum water content. For each soil, nine samples were prepared.
    2.3. Evaluation Procedures
    To evaluate the models, two parameters; root-mean-square error (RMSE) and the coefficient of determination (R2) were used.
    Which were calculated as follows:(6)
    (7)
    Where:θm and θp=the measured and predicted volumetric soil water content, respectively, in cm3 cm-3, n=the number of paired observations, and =the mean of measured values in cm3 cm-3.
    2.4. Comparison between SWCC Models
    An optimization routine was used to fit the parametric models to the measured data by altering the fitted parameters iteratively until the squared differences between the predicted and measured θ (ψ)data were minimized. The sum of the squared residuals (SSR) is defined as
    (8)
    Results and Discussion3.1. Evaluation between SWCC Models
    The R2 and RMSE calculated for the clay soil are close to 1 and 0, respectively, as shown in Table 3. Mean values of the RMSE for the five models: VG, FX5, Russo, Expotential and Tani are, respectively, 0.01872, 0.0189, 0.07755, 0.2323 and 0.04106 cm3cm-3. Therefore, in all models, amounts of both R2 and RMSE were able to estimate the moisture curve. All models provide the best performance in clay soil but the FX5 and Tani models provide the better and weakest performance compared to the other methods, respectively .
    Table 3. SSR Parameters and R2 and RMSE of 3.1. Evaluation of Models for Clay Soil
    Parameter/Model Tani Expotential Russo VG FX5
    Witness SSR 0.02077 7.710-3 0.0139 7.710-4 7.510-4
    R2 0.815 0.932 0.69 0.993 0.993
    RMSE 0.0832 0.0507 0.084 0.028 0.194
    modified compaction dry SSR 2.910-4 2.610-4 2.410-4 9.410-4 4.710-4
    R2 0.984 0.986 0.987 0.949 0.975
    RMSE 0.0099 0.0092 0.011 0.031 0.015
    optimum SSR 8.110-4 2.510-4 4.310-4 1.6510-4 5.110-4
    R2 0.97 0.991 0.985 0.994 0.982
    RMSE 0.0165 0.0092 0.015 0.013 0.0131
    wet SSR 1.910-3 4.810-4 110-3 6.9910-5 5.110-4
    R2 0.95 0.988 0.974 0.998 0.987
    RMSE 0.022 0.013 0.022 0.0084 0.0159
    standard compaction dry SSR 3.2510-3 1.110-4 1.910-3 9.7510-5 1.110-3
    R2 0.927 0.973 0.955 0.998 0.977
    RMSE 0.029 0.0199 0.032 0.0099 0.022
    optimum SSR 4.910-3 1.710-3 310-3 8.8810-5 1.110-3
    R2 0.91 0.969 0.945 0.998 0.982
    RMSE 0.035 0.0239 0.0389 0.0094 0.022
    wet SSR 7.210-3 2.3410-4 4.410-4 9.610-5 9.510-4
    R2 0.89 0.965 0.935 0.9986 0.986
    RMSE 0.042 0.0023 0.047 0.0098 0.0218
    reduced compaction dry SSR 9.410-3 3.5910-3 6.110-3 5.1610-4 1.510-3
    R2 0.87 0.951 0.918 0.9931 0.979
    RMSE 0.056 0.036 0.055 0.0227 0.0278
    optimum SSR 0.011 3.510-3 6.610-3 2.510-3 1.810-3
    R2 0.88 0.959 0.923 0.9699 0.979
    RMSE 0.051 0.034 0.0575 0.051 0.03
    wet SSR 0.0133 3.710-3 8.0410-3 3.3710-5 1.610-3
    R2 0.867 0.963 0.919 0.9997 0.984
    RMSE 0.66 0.035 0.063 0.0058 0.028
    Conclusions
    In this study, using the field data and laboratory analysis of SWCC models were evaluated. The results of this study can be summarized as follows:1. Among the fitting models to experimental models by Matlab, FX5 and VG models Provided the best performance compared to other models and Thani model presented the weakest performance.
    2. There is poor correlation between the measured and predicted values of and in models FX5 and VG.
    3. The amount of α by increasing compaction and also moisture have increasing trend and in high compaction with increasing moisture is a constant value.
    survey and identify appropriate models to estimate SWCC is crucial in saving time and costs compacted clay soil, soil water storage, predicting the hydraulic conductivity and soil moisture, and generally survey the behavior of the clay liner in landfill.
    Keywords: Clay soil, compaction, Moisture, Pressure Plate apparatus, Fixed Parameters
  • Arman Naderi, Mohammad Amir Delavar *, Babak Kaboudin Pages 87-100
    Introduction
    Accumulation of heavy metals in soil has been considered as an important global environmental issue during past decades and many efforts have been done to prevent their detrimental effects on ecosystem cycles. Conventional methods for assessing the spatial distribution of soil heavy metals require many soil sampling and laboratory analyses making it very time consuming and costly. Furthermore, a quick and reliable monitoring of heavy metals concentration is crucial for a close to real time management of polluted regions. Remote sensing and satellite imagery have the potential to provide a quick, non-destructive and low cost tools for predicting and mapping the distribution of soil heavy metals. Accumulation of heavy metals in soil has been considered as an important global environmental issue during past decades and many efforts have been done to prevent their detrimental effects on ecosystem cycles. Conventional methods for assessing the spatial distribution of soil heavy metals require many soil sampling and laboratory analyses making it very time consuming and costly. Furthermore, a quick and reliable monitoring of heavy metals concentration is crucial for a close to real time management of polluted regions. Remote sensing and satellite imagery have the potential to provide a quick, non-destructive and low cost tools for predicting and mapping the distribution of soil heavy metals. Recently, for remote sensing modeling by satellite images, and application of these models to the ambient environment, smart models like artificial neural networks and genetic algorithms have shown good capabilities. The aims of this study were to evaluation of a linear model and hybrid algorithms consider the spatial distribution of soil heavy metals concentrations and to study its responsible factors, using remote sensing.
    Materials And Methods
    The rich lead and zinc mining areas in Angouran region, Zanjan province, which are unique in the Middle East, are led to the accumulation lead and zinc industries in the province. One of the main manufacturers is Iranian national lead company, which is located at 13 km of east the Zanjan, in Dizajabad region. The major activities of this company are the processing and extraction of lead and zinc in soils and stone powder containing these elements. The soil samples (n=300) were collected at 0 to 5 cm soil depths based on a 250m grid in industrial and agricultural regions and a 500m grid in bare lands. The soil samples air dried and 2mm-sieved. Total (t) forms of zinc, lead, cadmium and copper were determined for each sample. In each sampling point, the mean value of digital numbers was calculated by averaging image pixel’s values within a 30m radius in MATLAB. To observe the quantitative relationships between spectral parameter values and metal levels in the studied area, stepwise linear regression and back propagation artificial neural network-genetic algorithm were applied. After providing descriptive statistics and data normalization, data modeling of heavy metals concentrations, Zn, Pb, Cd and Cu was conducted using stepwise multivariate linear regression models and neural-network model combined genetic algorithm. Modeling by neural network-genetic algorithms, was done using feed-forward multilayer perceptron neural networks with sigmoid transfer function. Seven neurons, including satellite and network output to a neuron contains concentrations of heavy metals, formed the input layers of the artificial neural network. Spatial autocorrelation analysis was used to evaluate the heavy metal source identification and find their hotspots. Autocorrelation analysis describes the spatial properties of a variable in a region and is a reflection of the space mean differences between all space cells and their neighboring cells. To investigate the spatial autocorrelation analysis the local Moran I, were employed to identify the presence of clusters.The validation of models was done by Root mean square error and coefficient of determination (R2) Statistics. The prediction maps were provided by most models with lowers Root mean square error and highest R2. Analysis of satellite images, drawing of heavy metals maps were conducted using ArcGIS software version 10.
    Results And Discussion
    Descriptive statistics obtained from chemical analysis of heavy metals concentrations in soil of the study area. The results indicated that average concentrations of Pb (t) Zn (t), Cd (t) and Cu (t) were 354.98, 501.10, 1.92 and 12.69 mgkg-1, respectively. According to the standards of the Department of Environment of Iran, Mean concentrations of lead and zinc were classified in risky level, and the average value of Cd and Cu were classified in the no risky level. Statistical analysis of multivariate stepwise linear regression model and artificial neural network-genetic algorithm model showed root mean square error of training data with neural network-genetic algorithm model for Pb, Zn, Cd and Cu were 0.07, 0.09, 0.17 and 0.17 respectively, and with the multivariate stepwise linear regression model were 0.45, 0.32, 0.48 and 0.54, respectively. The results of the models test also had similar trends. Models coefficient of determination of artificial neural network-genetic algorithm model for Pb, Zn, Cd and Cu were 0.88, 0.80, 0.75 and 0.45 and of multivariate stepwise linear regression model were 0.53, 0.43, 0.44 and 0.43, respectively. The obtained training and test error values of neural network-genetic algorithm hybrid model were less than corresponding values of multivariate stepwise linear regression. On contrary, the values of coefficient of determination in of artificial neural network-genetic algorithm hybrid model were higher than corresponding values of multivariate stepwise linear regression. These results indicated that prediction ability of heavy metals especially in high concentrations by artificial neural network-genetic algorithm hybrid model was higher than linear models. The neural network-genetic algorithm model had acceptable accuracy to estimate the amount of heavy metals in soil using satellite imagery data in this study and were used to produce predict distribution maps of heavy metals in the area. According to the predicted maps, the area of highly risk region for Pb, Cd, Zn and Cu were 50.01, 2.00, 0. 2 and 0.04 percentage of study area, respectively. The spatial autocorrelation results can be used as a strategy for source identification and finding disturbing agents of heavy metals. After taking a confidence level of Moran values, the levels that were significantly greater than zero are indicated positive correlation between clusters of cells. Moran levels that were significantly smaller than zero, are indicated a negative correlation between adjacent cells. If the value were closer to 1, is indicated very little difference between the cells and if these values be closer to -1, are indicated large space differences. Spatial autocorrelation of Moran index indicated the strong hotspots concentration of Pb and Cd around industrial zones in the study area. The pattern of showed that Pb concentrations were affected by dominant wind, and the Zn distribution maps showed the concentration of these elements around industrial installations and streams. This indicated that industrial activities effect on heavy metals distributions strongly and might result in surface and ground water contamination.
    Conclusion
    This study defined the artificial neural network-genetic algorithm and multivariate stepwise linear regression models to predict the heavy metal distribution in different land-use by Landsat image. Root mean square errors of training data with artificial neural network-genetic algorithm model for studied heavy metals were lower than the linear model. Models coefficient of determination of artificial neural network-genetic algorithm training and testing hybrid model showed higher values than the linear model. The results showed the success of the artificial neural network-genetic algorithm model in prediction of the heavy metals distribution, using remote sensing techniques. The remarkable ability of hybrid models in the estimation of heavy metals in high concentrations was also observed. The concentrations of Cd, Cu, Pb and Zn showed a decreasing trend with increasing distance from the industrial installations. Moreover, the distributions of regional hotspots of Cu and Cd were similar and close to factories. In addition, the Pb concentrations were affected by wind direction and streams had effect the Zn transport in the studied area.
    Keywords: Soil pollution, spatial variability, Local moran index, Artificial neural network-genetic algorithm
  • Sepideh Omrani *, Mohammad Ali Dorri Pages 101-115
    Introduction
    Nitrate and phosphate can be considered as nutrient limiting of primary production and affecting on eutrophication in surface water. Even momentary increase in the nutrient can stimulate tremendous growth and productivity. Phosphorus limitation dominates in tropical terrestrial (because of effects of soil age) and marine ecosystems (because of effects of sequestration in calcareous sediments) while nitrogen limitation is raised in primary production and eutrophication in many estuarine areas. Although the effects of nutrient loading have been less studied in wetland ecosystems but they can strongly affected, by eutrophication. The coastal wetland of Caspian Sea (Gomishan) due to the expansion of drainage systems, urbanization, wastewater and aquaculture, are exposed was the eutrophication occurrence in coast, and rarely been studied. Furthermore, the residence time and climate change affect the eutrophication patterns in different coastal ecosystems. According to these issues, the necessity of this study was obvious in order to determine role limiting of nitrate and phosphate in Gomishan international wetland. In this paper, the relationship between Chlorophyll concentrations, phosphate, nitrate and turbidity and some environmental factors such as water temp, salinity, pH, have been studied.
    Matherials and
    Methods
    Gomishan international wetland is located in the north of Iran. The wetland from the west separated by a very narrow sandy strip, from the sea. Therefore, almost all its water is supplied through sea communication channels. Sampling in this study during May to September was done and were in six stations along the Gomishan wetlands that were sensitive to loading nutrient, including: estuarine of Gorganrud River (St2), drainage channel of Gomishan City(St3), overflow channel of Alagol international wetland (St4), input (St6) and output (St5)channels of shrimp site and border area of Magtymguly ( St7). Also, was selected one station of Caspian Sea.
    Some physical-environmental factors like salinity, pH, turbidity, water temperature, were measured by multiparameter portable system. In the laboratory, the nutrients were measured by a spectrophotometer (Hach Company). Furthermore, 0.5 L phytoplankton sample water from each station, was filtered by vacuum pump (0.45 µ filter paper) in the laboratory. Finally, the absorption of the extracts was read at the wavelengths of chlorophyll a pigments by a spectrophotometer and calculated using trichromatic method. The Linear regression and Pearson’s correlation between the nutrients and chlorophyll a were determined by SPSS.
    Discussion of
    Results
    The physic-chemical parameters are the major factors that control the dynamics and structure of the phytoplankton of aquatic ecosystem. Seasonal variations in these parameters have an important role in the distribution, periodicity and quantitative and qualitative composition of the species that live within them. According to the results of physico-chemical parameters in this study, non algal turbidity was high in the Gorganroud estuarine (S2) and the border area of Magtymguly (S7), in addition to Caspian Sea (S1) (Fig 1and2 a). So by reducing it during the study period, the availability rate of orthophosphate was increased (Fig 1and2 c). Non algal turbidity can produce low algal chlorophyll-to-nutrient ratios and cause a lack of relationship between chlorophyll and phosphorus in some regions. Effluent of industrial parks and human wastewater was the main reasons of high turbidity in S2.
    Furthermore, in stations mentioned above, in September compared to August, between increasing the concentration of Chla and nitrate and decreasing in orthophosphate, there was a positive correlation. Because nitrogen availability may boost the non-nitrogen-fixing cyanobacterial, and as result nitrogen played the limiting role. S2 and S7 respectively, were the southernmost and northernmost stations in Gomishan wetland.
    Changes of hydrological parameters during the study period at some stations
    In other studied stations, including drainage channel of Gomishan (S3), overflow channel of Alagol (S4) and input (S5) and output (S6) of shrimp site, between the increase of turbidity, Chla and orthophosphate there was a positive relationship. As a result, phosphorus played the limiting role in these stations. Furthermore, in S3 and S4, that were central stations of wetland, in September compared to August, nitrate concentration was low and orthophosphate was high (Fig 3 and 4 d,c). This issue showed, in the nitrogen resource constraints, as soon as obtaining a small amount of phosphate resources, N/P decreased, and blooms of cyanobacteria level increased in September (Fig 3 and 4 b).
    Significant increase of nutrients especially phosphate, indicated the development process of urbanization and wastewater, non-normative increase of aquaculture and farming activities that was effective on hydrologic drought of wetland. Furthermore, the results of Pearson correlation and Linear regression showed the significant correlation of orthophosphate with log Chla (P
    Conclusions
    We conclude that algal density changes resulting in algal blooms, which are cause wetland water quality degradation may be predicted based on timely sampling and analysis of key water quality parameters especially phosphate. Also for controlling runoff, prevent of development the open drainage channels is essential which abundantly have been seen around the wetland.
    Furthermore, interpretation of observed chla concentration, not limited to the inputs and or sediment composition in local scale, because the climate changes also were effective.
    Keywords: Chlorophyll a, Gomishan international wetland, Nitrate, Loading, Ortophosphate
  • Massoud Tabesh *, Ghasem Kazemnejad Sangroudi Pages 117-134
    Introduction
    Urban water and wastewater systems should be constructed and designed within the framework of sustainable development. Therefore the assessment of environmental impacts of these systems’ construction and operation is an essential issue. One of the environmental impacts is the global warming in which the equivalent carbon dioxide has the most important role.
    The equipments, energy and chemical materials used in drinking water cycle (including the phases such as withdrawal water from its resources, water treatment, water distribution, wastewater collection and treatment) have environmental impacts such as the intensification of global warming due to the increase in greenhouse gasses emission.
    There are various tools for sustainability assessment of water and wastewater systems. Life Cycle Assessment (LCA) is one of these tools. Unlike the three decade records of applying the LCA in the world, this method has been rarely employed in Iran to resolve the problems of real water and wastewater systems.
    In this study, the LCA of drinking water system has been implemented in order to estimate its impact on global warming and to examine different cases with minimum environmental impacts. Determination of the water cycle phases with the maximum impact on global warming has been also aimed. In this regard, released equivalent carbon dioxide in life cycle of drinking water was estimated by means of SiamPro software. Sari, a city (in north of Iran) in which drinking water is supplied from wells, has been selected as the case study. Three different scenarios for replacing groundwater resources by a dam reservoir (Shahid Rajaee dam) were studied.
    Materials And Methods
    In the present research, Sari city is selected as the case study (Figure 1). Population of the city is about 350,000 in which 57,000 inhabitants profit by the wastewater collection and treatment system. Drinking water cycle is divided into four phases including water withdrawal from its resources, water distribution, wastewater collection and wastewater treatment in which the electricity is supplied from thermal power plant.
    Figure 1. Map of the studied area
    Because of the nonexistence of required infrastructures, drinking water in Sari city was supplied from underground water resources before July 2015. In other words, drinking water in Sari city was supplied from 28 wells with discharge of 1180 l/s. 18% of this amount was lost due to the leakage. On the other hand, underground water resources have been exposed to pollution due to the usage of farming fertilizers and operating cesspools. Therefore, replacing underground water resources by Shahid Rajaee dam has been mooted. In this regard, water will be transferred from Shahid Rajaee dam to Kiasar water treatment plant. Then the treated water will be transferred to Sari city.
    Wastewater treatment plant of Sari has been designed in four modules. The first module which has been operated since 2010, serves about 105000 people. The average and the maximum input discharges of this module are 269 and 546 l/s, respectively.
    Three scenarios have been considered for replacing underground water resources by Shahid Rajaee dam. These scenarios are: 1) Supplying a part of Sari drinking water demand from Shahid Rajaee dam; 2) Supplying the total drinking water demand from Shahid Rajaee dam; and 3) Supplying the total drinking water demand from Shahid Rajaee dam and using hydroelectricity. It should be noted that the environmental impacts of dam construction has not been considered in these Scenarios.
    SimaPro is one of the common software for assessing the life cycle. In this study, SimaPro 5.1 is employed for calculating the greenhouse gasses produced in water and wastewater systems.
    Discussion of
    Results
    The total amount of the equivalent carbon dioxide produced in drinking water life cycle in Sari city is presented in Figure 2. According to this figure, the total amount of the equivalent carbon dioxide produced in drinking water cycle is 0.392 in which the phase of withdrawal water from its resources has the greatest part (about 60% of the total equivalent carbon dioxide) in producing the greenhouse gasses. Water distribution network, wastewater treatment plant and wastewater collection network have portions of about 20%, 12% and 8% respectively, in producing the greenhouse gasses.
    Figure 2. The equivalent carbon dioxide produced in drinking water life cycle in Sari
    According to the obtained results, water supplying from the Shahid Rajaee dam will reduce the environmental impact to a great extent. Scenarios 1 and 2 with common electricity production (in which 500 and 1500 l/s water was respectively supplied from Shahid Rajaee dam and was treated in Kiasr water treatment plant) reduce 84% and 86% of greenhouse gasses production in the water withdrawal phase, in addition to supplying water with higher quality. In scenario 3 with hydroelectricity, 89% of greenhouse gasses produced in the water withdrawal phase is reduced (Figure 3). The equivalent carbon dioxide produced by various agents in itroduced scenarios are shown in Figure 4.
    Figure 3. The equivalent carbon dioxide produced in the present situation and various scenarios
    Figure 4. The equivalent carbon dioxide relevant to various agents in scenarios 1-3
    Conclusions
    It can be concluded that operation of Shahid Rajaee dam and Kiasar water treatment plant and using hydroelectricity would lead to a great reduction in electricity consumption and producing greenhouse gasses. Another result is that the biggest share among the factors producing carbon dioxide is associated to electricity.
    Keywords: Drinking water life cycle, Greenhouse gasses, Life cycle assessment, SimaPro software, Urban water, wastewater systems
  • Sanaz Fathi, Roshanak Rezei Kalantary * Pages 135-148
    Article 10, Volume 43, Issue 1, Spring 2017, Page 135-148 XML PDF (1081 K)
    Document Type: Research Paper
    Authors
    1Department of Environmental Science, Faculty of Environment and Energy, Tehran Science and Research Branch, Islamic Azad University, Tehran, Iran
    2Research Center for Environmental Health Technology (RCEHT), Iran University of Medical Sciences, Tehran, Iran.
    Abstract
    Introduction
    Hexavalent chromium Cr(VI) is one of the top-priority toxic heavy metals in wastewater that can be found in many industrial effluents such as mining, battery and etc. There are many adsorbents like carbon materials purolite, chitosan zero-valent iron, and metal oxides have been used for Cr contaminated-water treatment. We used chemical vapor deposition (CVD) technique to synthesize nano-porous graphene (NPG) on transition metals that has recently been used for synthesizing large graphene domains. , magnetic nano-particles (MNPs) prepared for synthesis of NPG/Fe3O4 as an adsorbent for the economic and efficient removal of Cr ions from aqueous. Modification of graphene with different materials can produce various adsorbents for improving their adsorption capacity.The purpose of this work was the synthesis of nano-porous graphene (NPG) by CVD method and magnetite with MNPs (NPG/Fe3O4) for economic separation from water then functionalized with the carboxyl group for provide different nano-composite (COOH@NPG/Fe3O4) as an adsorbent for the removal of Crþ ions from aqueous solutions. The characterization of COOH@NPG/Fe3O4 surface was analyzed by several techniques such as FTIR, SEM and TEM. The impacts of optimal parameters such as pH of solution, contact time, temperature, initial ion concentrations and adsorbent dosage were studied. In addition, the adsorption experiments were conducted under varying conditions to investigate the equilibrium isotherms, kinetic models and thermodynamics.
    Materials And Methods
    2.1. Materials
    Anhydrous iron (III/II) chloride, (99.9 %) ammonia solution, potassium dichromate and (28 %) hydrazine hydrate were purchased from Merck, Co, Germany. A hand magnet was also prepared to separate adsorbents from solution. All the solution were prepared by ultrapure water and kept at 4 ˚C prior to use.
    2.2. Preparation of nano-porous graphene (NPG)
    Nano-porous graphene was synthesized by chemical vapor deposition (CVD) technique which is a highly effective and low-cost method.
    2.3. Synthesis of magnetite nano-porous graphene (NPG/Fe3O4)
    NPG/Fe3O4 nano-composite was synthesized according to method reported in the previous studies (Juang et al. 2010) with some modifications.
    2.4. Functionalization of magnetite nano-porous graphene with Carboxyl (COOH@NPG/Fe3O4)
    Nano-porous graphene was functionalized by carboxyl. About 1 g of graphene was treated in 25 ml of nitric acid and 75 ml of sulfuric acid for 3 h at 60 ˚C. The mixture was kept in an ultrasonic bath and then washed by distilled water until reaching to the natural pH.
    2.5. Characterization of the synthesis adsorbents
    A scanning electron microscope (SEM, model MIRA3, Tescan, Czech Republic) was used to measure surface morphology, size and distribution of synthesized adsorbents. The XRD pattern of the adsorbent was analyzed (Quantachrome, NOVA 2000) using graphite monochromatic copper radiation (Cu Ka, λ =1.54 Å) in the 2θ range of 10-70˚ at 25 ˚C. The morphological and shape of the adsorbent were recorded by a transmission electron microscope (TEM, model PHILIPS, EM 208 S) with 100 keV. In addition, the surface functional groups were characterized by fourier transforms infrared spectroscopy (FTIR) (Tensor 27, Bruker, Germany). VSM (7400, Lakeshare) was also applied to determine the magnetic properties of adsorbent at 10 kOe at 25 ˚C.
    . The effect of operating parameters such as pH of solution (2-10), contact time (5-120 min), adsorbent dose (20, 35, 50, 100, 150 and 200 mg/L), temperature (283, 298, 303 and 323 K) and different concentrations of Cr (25, 50, 100,150 and 200 mg/L) on the adsorption efficiency was investigated.
    2.7. Isotherm, Kinetic and thermodynamic of adsorption
    The Langmuir and Freundlich isotherm models were used to evaluate Cr adsorption onto the adsorbent . The adsorption kinetic models of Cr on COOH@NPG/Fe3O4 adsorbents along with their corresponding regression coefficients are calculated. The thermodynamic diagram of Cr adsorption is demonstrated.
    Results And Discussion
    3.1. Characterization of the synthesized adsorbent
    The FTIR spectra of synthesized composite of COOH@NPG/Fe3O4િ and NPG/Fe3O4િ that characterize the functional groups on the adsorbent surfaces that can play an important role in the adsorption mechanism, is demonstrated in Fig 1d. View of magnetic nanoparticles at a wavelength of 582 cm-1 confirms the Fe-O bonds between groups are in the form of tetrahedron. The other groups that have emerged in the wavelength of 1421.86 cm-1 and 3312 cm−1 can be assigned to represents aromatic C=C bonds and OH stretching vibrations of the carboxylic acid group, respectively. Finally, alkoxy CO bond is defined at 1029 cm-1 which indicates the graphene structure of NPG. The peak around 1700 cm−1 appears in the spectra of COOH@NPG/Fe3O4િ .
    In addition, Fig 1e represents the morphology, size and surface area of the NPG that were analyzed by SEM in high magnification; it can be see good porosity and high adsorption capacity. By TEM technique could be pointed out that a high density of Fe3O4 nanoparticles is noticed on the NPG layers (Fig 1f) low-magnification and Fig 1g high-magnification).
    3.3. The effect of pH
    The amount of Cr removal in various ranges of pH between two adsorbents is shown in Fig 2a. According to a similar study, the adsorption of Cr on COOH@NPG/Fe3O4 was significant at acidic conditions.
    3.3. The effect of time on Cr (VI) adsorption onto COOH@NPG/Fe3O4
    The contact time is one of the most essential parameters in designing a batch system that affects the adsorption of contaminants. As shown in Fig 2b.
    3.4. The effect of adsorbent dosage on Cr (VI) adsorption onto COOH@NPG/Fe3O4
    The effect of the optimal absorbent concentration (20, 35, 50, 100, 150 and 200 mg/L) on the 100 mg/L Cr (VI) removal under optimal condition (pH=3, t=60 min, 200 rpm, 25 ˚C) is shown in Fig 3a
    3.5. Effects of different Cr concentrations
    The effect of various chromium concentrations (25, 50, 100, 150 and 200mg/L) under optimum conditions (pH=3, time=60, 200 rpm, m0=0.2 g/L) is shown in Fig 3b.
    3.6. Adsorption isotherm models
    Equilibrium adsorption isotherm models are used for better explanation of adsorption capacity between adsorbent and adsorbate which is an important factor in optimizing the application of adsorbents. The obtained values based on both Langmuir and Freundlich models for Cr sorption on COOH@NPG/Fe3O4 at ambient temperature and optimum conditions are shown
    3.7. Kinetic study
    The adsorption kinetic models of Cr on adsorbent along with their corresponding regression coefficients are given in Table 3. These are further verified by the diagrams presented in Fig 7. According to the regression coefficient (R2) in Table 3, the adsorption kinetic data was well-fitted by the pseudo second-order model.
    3.8. Thermodynamic of adsorption
    The thermodynamic diagram of Cr adsorption is demonstrated. The results were obtained by the curve where the values of ΔH◦ and ΔS◦ can be achieved from the slope and intercept of the plot of lnK◦ against 1/T.
    Conclusion
    In this study, nano-porous graphene (NPG) was synthesized by chemical vapor deposition (CVD) method then magnetized by Fe3O4 and Fe2O3 powder for both rapid and economic separation by external magnetic field, due to its magnetism contributed from Fe3O4 instead of older method. The NPG/Fe3O4 was also functionalized with carboxyl (COOH@NPG/Fe3O4) for using as an adsorbent for removal of Cr from aqueous solution. The structural, functional and morphological properties of synthesized adsorbent were characterized using SEM, TEM, XRD, FTIR, BET and VSM techniques. The optimum experimental conditions of Cr removals using NPG/Fe3O4 was investigated in batch adsorption experiments. The adsorption efficiency of Cr was increased with decreasing the pH of solution and initial Cr concentrations. But, an increasing trend was happened in Cr adsorption efficiency with increasing the adsorbent dosage and contact time until 60 min. In addition, the adsorption data was fitted well with Langmuir isotherm model. The Langmuir model indicated that it is monolayer adsorption of Cr on the adsorbent surface. Kinetic data of adsorption can be best described by a pseudo second-order model. The sorption reaction onto adsorbent was an endothermic and spontaneous process. It should be noted that the synthesized adsorbent has promising potential in wastewater treatment which can easily be separated via an external magnet
    Keywords: heavy metal, Adsorption, termodynamic, Isotherm
  • Rasool Zamani Ahmad Mahmoodi, Roholah Mirzaei * Pages 149-161
    Introduction
    Inorganic contaminants, such as heavy metals enter into terrestrial and aquatic ecosystems from different paths such as erosion and weathering of rock, agricultural and industrial activities, automobile exhaust, sewage and atmospheric subsidence. These heavy metals because of their bioaccumulation potential, toxicity, ubiquitous, and resistance degradation, can be a serious threat to ecological systems and human health. According to Amin et al (2009), more than 90% of heavy metals loading in aquatic ecosystems found in sediments; so, the quality of sediments can be a good indicator of water pollution. In these ecosystems, sediments play an important role as a sink for organic and inorganic contaminants (heavy metals) and provide a history of human-origin emission of pollutants and environmental changes.
    To address the sediment contamination by heavy metals, different approaches such as hazard quotients; crop uptake and transformation; concentrations of weakly extractable metal and total heavy metal concentration can be used.
    sediment contamination is often assessed by comparing heavy metal concentrations with the relevant environmental references or by quantifying an accumulation factor in comparison to the related background concentrations. Up to now, numerous different indices such as the index of geoaccumulation (Igeo), the enrichment factor, the pollution index (PI) and the integrated pollution index (IPI), the individual element polluted index, the contamination factor and degree of contamination, the contamination factor (CF), the pollution load index (PLI) and the total contamination index (Zs) has introduced to estimate the degree of heavy metal contamination.
    Up to now, numerous studies have documented the distribution, origin and extent of heavy metals contamination in sediments of various wetlands. However, wetland sediment contamination has sparsely been investigated in Iran in general and no information is available for the Choghakhor wetland. Choghakhor wetland is one of the most important wetland for waterfowl in Iran which has been exposed to different non-point pollution sources and different contaminants such as heavy metals due to surrounding agricultural and recreational activities and discharge of domestic effluents without treatment. Therefore, the aim of this study was to quantify the concentrations of Ni, Zn, Cu and Fe in surface sediments of Choghakhor wetland. Also assessment of heavy metals contamination using different contamination indices was another purpose of this study.
    Materials and Methods
    A total of 52 surface sediment samples were collected randomly from different parts of the Choghakhor wetland; then the samples were placed in clean plastic bags and were transferred to the laboratory for further analysis. 1 gram of sieved sediment sample was digested by using the combination of the three acids: HF, HNO3 and HClO4 whit the ratio of 3:5:7. After cooling the samples, 2 ml of boric acid 7% was added to remove the fluoride residual and with distilled water was reached to volume of 25 cc. The concentration of metals in sediments was measured by flame atomic absorption. For quality control and assurance, standard reference materials and blank samples were used.
    Various types of direct (Earth Chemical) and indirect methods (statistical) are commonly used to calculate the contamination of heavy metals in the environment. However, statistical methods are more common than chemical methods because the earth is not alone useful for determining the concentration of background samples, also statistical methods have lower lab work and cost. In this study, a statistical method introduced by Ismailia et al (2014) was used for calculating of the background concentrations. Contamination assessment was carried out using several different indices including Enrichment factor (EF), Geo-accumulation index (Igeo), Contamination factor (CF) and pollution load index (PLI).
    Sediment quality assessment guidelines (SQGs) can be very useful in determining the amount of sediment pollution compared with the corresponding guides. In this paper, two sets of guidelines including National Oceanic and Atmospheric Administration USA (NOAA) and the Interim Sediment Quality Guidelines Canada (ISQG) were used. These guidelines express the quality level and degree of contamination of sediments which may have an adverse effect on aquatic organisms. The Correlation and PCA analysis were used to determine the source of heavy metals in sediment samples. Inverse distance weighting method was used for mapping of heavy metals distribution in surface sediments of wetland.
    Discussion of
    Results
    The mean total concentrations of Cu, Fe, Mn, Ni and Zn in surface sediments in the whole study area were 15.75, 6076.86, 297.74, 30.07 and 29.87 mg/kg, respectively. Average metal concentrations followed the order Fe> Mn> Ni> Zn> Cu. With the exception of Fe, the concentrations of other heavy metals in the surface sediments of Choghakhor wetland were all lower than the background values.
    Mean EF values of heavy metals followed the order: Ni> Zn> Cu> Mn. Average EF values for Ni, Cu, Zn and Mn were 1.34, 2.47, 1.75 and 2.54 respectively suggesting a minor enrichment of these metals. Considering background values, enrichment of heavy metals in this study showed that heavy metals concentrations in sediment samples were mostly controlled by natural and partly anthropogenic sources. Average Igeo values for Ni, Cu, Zn, Mn and Fe were 0.014, 0.032, 0.018, 0.005 and 0.0001 respectively indicating no pollution in wetland sediment samples. However, Igeo is not readily comparable to the other indices of metal contamination due to the nature of the Igeo calculation, which involves a log function, and a background multiplication of 1.5. Mean CF values for Ni, Cu, Zn, Mn and Fe were 0.48, 0.65, 0.59, 0.68 and 0.48 respectively indicating low contamination of heavy metals in wetland sediment samples.
    Results of correlation analysis showed that the heavy metals concentrations of sediment samples were significantly correlated with each other at level %1. From this, it could be said that their source was almost the same and which may be derived from the natural sources. Considering PCA analysis, all the heavy metals were well represented by the first principal component, which accounted for over 64.79% of the total variance. The results of PCA agreed well with that of the correlation analysis. As mentioned before, the concentrations of most heavy metals were lower than the background values. Therefore, it could be said that the distribution of heavy metals in sediment samples was mainly controlled by natural sources.
    In this study, we analyzed the spatial distributions of heavy metals in the whole area of Choghakhor wetland. The spatial distribution patterns of most of heavy metals, especially Cu, Fe and Ni were generally similar, with increasing concentrations from the north of the wetland to the south nearby villages and residential areas. In other words, the high concentrations or hotspots for the three heavy metals mainly existed in southern parts of the area under study. In addition, the spatial distribution of Mn and Zn concentrations showed decreasing trends from the west of the area to the east.
    Therefore, from the above discussion can be concluded that although entire wetland is non-polluted and the heavy metals concentrations in sediment were mostly controlled by geomorphological sources but high concentrations of heavy metals in specific areas or hot spots could be related to human activities especially agricultural activity. In particular, these hot spots are located in environmental guard station, tourist area and residential areas especially villages of Kheder Abad, Saki Abad, Seyf Abad and Khani Abad in the vicinity of wetland.
    Conclusions
    Results indicated that the average concentrations of heavy metals were all lower than background values. According to the results of Contamination Factor, Geoaccumulation Index and Enrichment Factor, considerable and intense contamination of heavy metals in sediments of study area was not observed. Based on the sediments quality guidelines, the concentration of Ni at whole study area has frequently adverse biological effect on aquatic organisms. Although, the results of the PCA revealed that all heavy metals were mainly originated from natural sources, their spatial distribution maps showed that there were several hotspots located in different parts of the area under study.
    Keywords: Toxic metal, Sediment, soil pollution index, Zoning, Choghakhor Wetland
  • Mostafa Farhadian *, Omid Bozorg Haddad, Maryam Pazoki Pages 163-180
    Materials and Methods
    2.1. Environmental flow calculation
    To calculate the Environmental flow of rivers, many different methods have been proposed. These methods can be classified into four main categories (hydraulic, hydrologic, simulation settlement and comprehensive methods). In this study due to lack of sufficient data, hydrological methods used to determine the environmental flow, because the hydrological methods are simpler than other methods.
    2.2.
    Purposes
    In this study, five purposes in determining the optimal release are intended. As mentioned earlier, one of the main purposes of this study is supply environmental flows. Therefore the first target is the environmental flows supplement. Gotvand dam has been constructed to meet the water requirements of hydropower generation purposes, flood control, agricultural water management and create tourist attractions. Therefore, one of the aspects that needs to be considered in determining the optimal release is to meet these purposes. It is necessary to define the second objective as reliability to determine the optimal release streams while dams purposes also be considered. Taking account the purpose of reliability among the other purposes of the dam, causes the supply of water needs for all purposes (hydropower generation purposes, flood control, agricultural water management and create tourist attractions) in determining the optimal release, be considered.
    Another important target related to this issue is supply of high-quality water for downstream regions. Given that the drinking water in the downstream regions including the Ahwaz city, is supplied from the Karun river and given the importance of providing high-quality drinking water, it is necessary to put a purpose to supply a high-quality water. Therefore, another purpose as supply downstream water demands has defined to provide high-quality water for downstream regions.
    Surface water pollution is an important phenomenon that is threatened humans health, animals and the environment. Thus, in addition to the environmental flow, it is also necessary to consider a purpose to manage and control river pollution constantration.
    There are two river pollution targets due to behavior of the release flow. The two conflicting targets are “average concentration” and “length polluted”. To calculate the average concentration of greater than one ppm, concentrations are averaged and the average value is considered as the concentration of BOD indicator for release flow. Concentrations less than one milligram/liter are not accounted because the water in which concentrations of BOD indicator is smaller than one milligram/liter, is considered pure. The mathematical definition of the average concentration is illustrated:1.1. Conflict resolution model
    If there is more than one stakeholder in the decision-making process, due to the different aims and different priorities of the views of stakeholders, decision-making process will have not made such as lack of agreement. In such matters, it is the decision in such a way that all views of all stakeholders are taken into account, and the rights of all stakeholders be met. One way to solve this kind of problem is using models of conflict resolution. One of the common conflict resolution methods is Nash.
    1.2. Case study
    One of the main aims of this study was to determine the environmental flow in the Gotvand dam location to downstream of shoshtar city. Karun is the most important river of Iran and it has the largest discharge of water among the Iran's rivers. The length of this river is 800 km and long-term average annual flow of the river is 453 m3/s and average. For the purposes of this study, all data were collected from the study area. This data includes the release of dam, river hydraulic details and characteristics are sources of pollutants.
    Discussion of Results &
    Conclusions
    In this part, the results will be discussed. At the first, by using the QUAL-2K model, water quality simulations is done and then the simulation results to calculate purposes and average concentrations and length polluted are used. Finally, by using the theory of Nash conflict resolution, the optimal release under three scenarios relative weights is determined.
    2.1. Environmental flow calculation
    Environmenta flow of Karun River in the study area was calculated by using flow-based Tennant (1976) and Aquatic Base Flow methods. The range environmental flow was 45 to 272 (m3/s).
    2.2. Simulation BOD in the range of dam release
    Qualitative simulations for releases from the dam flows of the range of 13 to 458 have been done by using the QUAL-2K.
    2.3. Calculation of average concentrations and length polluted
    Once the river's qualitative simulation is finished, BOD indicator concentrations along the river are obtained for each discharge flow releases from the dam. Using the obtained concentrations, the average concentration and length of contact with the river can be calculated. Therefore, the mean concentrations were calculated for different values of release flow from the dam.
    By increasing the release rate, due to increased volume of water and dilution of contamination concentrations, the average concentration decreases and vice versa. But as the flow rate increases, due to increased flow velocities, unallowable concentrations run longer in the river and increase the length of the contact, and vice versa. This issue is of great importance in determining the proper locations for the water extraction from the river. This is especially important in downstream areas that are used to supply drinking water to riverside water. Downstream of the study area, contains many cities and villages such as Ahwaz. Therefore, it is necessary to determine the release rate in such a way that the concentration of water pollution of the river before reaching the water extraction points, has fallen to the standard limits.
    2.4. Determining the optimal release
    One scenario has been defined to evaluate impact of relative weights that was determined according to the different qualitative and changes various conditions. Normalization of data to assess the importance of purposes is necessary in conflict resolutions methods. According to Nash conflict resolution model, before running the optimization model of conflict resolution, it is necessary set out the minimum acceptable level for each of the purposes. The minimum acceptable level for each of the five purposes listed in the previous section, were defined
    After normalization of the data of the purposes and determining their minimum acceptable level, for each of these purposes, relative weights should be determined according to their importance. But relative weights depend on many conditions including economic, social, climate (wet or drought), and so on. Therefore, these conditions may always change at any time, and the relative weights of purposes should be changed. Relative weights are used to indicate the importance of each purpose on determining the release rate of the dam. In the present study, the relative weight of purposes has been determined based on the author's experiences. Therefore, in order to apply the results of this research, it is necessary to determine the relative weights of each purpose according to the time conditions and existing expectations. In this study, one scenario of relative weights is defined. In this scenario, relative weights for all purposes are equal to and equal to one.
    At last, by using Nash conflict solution method, optimal flow releases from the dam under one relative weights for purposes, was determined. The amount of released flow from the dam to the scenario was184 m3/s.
    Keywords: flow release, Environmental flow, Water quality, Conflict resolution, Karun river and Gotvand dam.
    Keywords: flow release, Environmental Flow, water quality, Conflict resolution, Karun river, Gotvand dam