فهرست مطالب

محیط شناسی - سال چهل و پنجم شماره 3 (پیاپی 91، پاییز 1398)
  • سال چهل و پنجم شماره 3 (پیاپی 91، پاییز 1398)
  • تاریخ انتشار: 1398/08/01
  • تعداد عناوین: 12
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  • محمود احمدی*، عباسعلی داداشی رودباری صفحات 379-394

    ذرات معلق موجود در جو نقش چشمگیری در سامانه آب وهوا و سلامت عمومی دارند. اهمیت ذرات معلق توجه زیادی را به توسعه روش هایی برای برآورد ذرات معلق (PM2.5) کرده است. هدف از این پژوهش توزیع زمانی-مکانی ذرات معلق (PM2.5) در غرب و جنوب غرب ایران است در این راستا داده های عمق نوری هواویز (AOD550nm) سه سنجنده SeaWifs، MISR و MODIS طی دوره آماری 1998 تا 2016 اخذ و سپس با استفاده از روش رگرسیون وزن دار جغرافیایی (GWR) با کاربست ایستگاهای کنترل کیفی هوا مقدار PM2.5 با تفکیک 01/0 درجه قوسی محاسبه شد. کارایی مقادیر برآورد شده با استفاده از روش های R2 و RMSE مورد تایید قرار گرفت. نتایج نشان داد استان خوزستان (µm/m3 29/15) بیشینه و استان همدان (µm/m3 16/10) کمینه PM2.5 را دارا می باشند. بیشینه ضریب تغییرات و روند PM2.5 در مناطق مرزی به دلیل بار ورودی هواویزهای گردوغباری است. مقدار ذرات معلق از جنوب به شمال و غرب به شرق روندی کاهشی را به دلیل توپوگرافی پیچیده، عوامل بیوفیزیکی، عوامل هواشناسی و دوری از چشمه های گردوغباری دارند. بر اساس دستورالعمل کیفیت هوا (AQG) و استاندارد سازمان محیط زیست ایران بترتیب 31/26 و 11/40 درصد از منطقه موردمطالعه کمتر از دستورالعمل های نامبرده قرار دارند.

    کلیدواژگان: برآورد ذرات معلق، ذرات معلق (PM2.5)، عمق نوری هواویز (AOD)، سنجش ازدور، غرب و جنوب غرب ایران
  • علی بهشتی اردکانی، امیرحسام حسنی*، همایون احمدپناهی، امیر حسین جاوید، الهام منیری صفحات 395-412

    در این تحقیق به بررسی عملکرد یک نانوجاذب اصلاح شده در حذف کل هیدروکربنهای نفتی (TPH) - عنوان شاخص آلاینده نفتی - پرداخته می شود. بدین منظور نانو ذرات اکسید قلع با ترکیب 3- مرکاپتو پروپیل تری متوکسی سیلان در دی اکسان اصلاح گردید. سپس مونومر عامل دار شده از طریق آلیل بوتیل اتر و N,N- دی متیل آکریل آمید بر روی بدنه نانو ذرات اصلاح شده پیوند داده شد. نانو جاذب تهیه شده با طیف اسپکتروسکوپی تبدیل فوریه مادون قرمز، میکروسکوپ الکترونی عبوری (TEM) و (SEM) مورد بررسی قرار گرفت و نتایج نشان دهنده تشکیل جاذب نانو اکسید قلع با عامل های سطحی مورد نظر در محدوده اندازه 50-30 نانومتر می باشند. اثر پارامترهای pH، دمای واکنش و زمان تماس بوسیله اندازه گیری TPH بوسیله دستگاه کروماتوگرافی گازی مورد مطالعه قرار گرفت که بررسی ها نشان می دهد که pH و زمان بهینه برای جذب TPH از آب به ترتیب برابر 5 و در حدود 10 دقیقه می باشد. بررسی ایزوترمهای جذب و مدلهای کنتیک جذب نشان می دهند که فرآیند جذب آلاینده های نفتی از آب توسط نانو جاذب ساخته شده از ایزوترم لانگمویر و مدل کنتیک سودوی مرتبه دوم پیروی می کند. نهایتا این جاذب توانایی حذف حدود 85% از آلاینده های نفتی از نمونه آب واقعی را دارد.

    کلیدواژگان: حذف نفت، نانوجاذب اصلاح شده، نانوجاذب اکسید قلع، حذف هیدروکربن های نفتی از آب
  • سیمه ارغوانی، حسین ملکوتی*، عباسعلی علی اکبری بیدختی صفحات 413-429

    کمربند سبز با هدف بهبود آسایش محیطی، جلوگیری از توسعه شهر و بهبود کیفیت هوا در تهران در حال اجراست. در این مطالعه از مدل هواشناسی WRF جفت شده با مدل کنوپی شهری تک لایه، مدول شیمی جو و مدل بیوشیمی MEGAN برای شبیه سازی عددی عملکرد کمربند سبز در بازه در بازه زمانی 15 تا 30 ام ماه ژوئن سال 2016 استفاده شده است. در اجرای کنترل، کسر سبزینگی شهری از تصاویر ماهواره سنتینل A2 بروزرسانی و به مدل معرفی شد. کمربند سبز تهران بصورت ایده آل طراحی و نتایج شبیه سازی عددی آن با اجرای کنترل مقایسه گردید. نتایج موید نقش قابل توجه کمربند سبز بر بهبود آسایش محیطی بدلیل کاهش محسوس دما و افزایش سطح رطوبت نسبی در سطح شهر می باشد. تغییر سرعت و جهت باد محلی و کاهش ارتفاع لایه مرزی جوی بدلیل کاهش دمای سطح و فرآیندهای تلاطم وهمچنین تغییر الگوی پخش جوی موجب افزایش غلظت سطحی آلاینده هایSO2 ،NO2 ،CO و O3 شده است. به منظور کاستن اثرات نامطلوب کمربند سبز، مطالعه تخصصی کارایی گونه های گیاهای به منظور کاشت بصورت غیر متراکم با ارتفاع محدود، سازگار با خاک و اقلیم منطقه و امکان سنجی تامین آب آبیاری پیشنهاد می شود.

    کلیدواژگان: کمربند سبز، آسایش حرارتی، کیفیت هوا، WRF، Chem، SLUCM، کلان شهر تهران
  • ساحل شاهی زارع، اسلام کرمی*، مجتبی رفیعیان صفحات 431-451

    چکیده اصول و معیارهای مربوط به کیفیت محیط و ارتباط این کیفیت با زمینه های فرهنگی، تاریخی و اجتماعی آن در طراحی مجتمع های مسکونی نادیده گرفته می شود و همین مساله، سبب کاهش میزان رضایتمندی ساکنان از مجتمع ها می شود. لذا پژوهش حاضر با هدف ارتقاء کیفیت مجتمع های مسکونی اردبیل از طریق مولفه های زمینه گرایی به روش توصیفی- تحلیلی با استفاده از ابزار پرسشنامه به روش نمونه گیری تصادفی- خوشه ایانجام گرفته است. نتایج یافته های پژوهش نشان می دهد که ارتباط خطی بین مولفه های زمینه گرایی و کیفیت سکونت مجتمع های مسکونی برقرار است. از نظر تاثیرگذاری، مولفه کیفیت زمینه ای و مولفه شرایط بیرونی واحدها به ترتیب بیشترین تاثیر را بر کیفیت مجتمع های مسکونی و کیفیت واحدهای مجتمع های مسکونی اردبیل دارا است. از بین مولفه های زمینه گرایی نیز، زمینه طبیعی (بویژه بعد احترام به طبیعت و محیط زیست) بیشترین اثرگذاری را بر کیفیت سکونت مجتمع های مسکونی اردبیل دارد. بنابراین برای ارتقاء کیفیت سکونت در مجتمع های مسکونی لازم است برنامه ریزان و طراحان معماری و شهری علاوه بر توجه به کیفیت زمینه ای مجتمع ها و نیز شرایط بیرونی واحدهای مسکونی، به زمینه طبیعی شامل احترام به طبیعت و حفاظت از محیط زیست توجه و تاکید بیشتری داشته باشند.

    کلیدواژگان: زمینه گرایی، کیفیت سکونت، مجتمع مسکونی، واحد مسکونی، اردبیل
  • ویدا رفیعی*، فریبا وحیدزادگان، رکسانا عبداللهی صفحات 453-469

    چکیده کلان شهرهای کنونی فاصله زیادی با شاخص های پایداری دارند و توازنی در بین شبکه های شهری و شبکه های اکولوژیک آن ها مشاهده نمی شود و با پیشرفت بافت های شهری بر الگوهای طبیعی آسیب پذیر، نیاز به وجود طبیعت، بیشتر نمایان می گردد. در پژوهش های پیشین با دیدگاه های صرفا محیطی یا مدل های کیفی یا کمی هرکدام به صورت جداگانه، به برنامه ریزی زیرساخت های سبز پرداخته شده است؛ در پژوهش حاضر به تلفیق دو روش کیفی و کمی AWOP MODEL و GRAVITY MODEL و تطبیق آن ها با استراتژی های بازآفرینی مناظر طبیعی - تاریخی منطقه سه شهر اصفهان پرداخته شد. منطقه مورد نظر دارای بافت بسیار متراکم و فرسوده بوده که دارای معضلات محیطی، اجتماعی و منظرین بسیار است. نتایج پژوهش نشان می دهد بهترین الگوی شبکه زیر ساخت های سبز در این منطقه شهری که امکان توسعه زیرساخت های سبز در آن تقریبا غیر ممکن به نظر می رسید، از حاصل ترکیب ماتریس سلسله مراتبی و بکمن امکان پذیر است و ضمن ایجاد پایداری منجر به بازآفرینی عناصر ساختاری طبیعی - تاریخی پرارزش محدوده در قالب های جدید با حفظ هویت گذشته، که هدف پژوهش پیش رو است نیز خواهد شد. شیوه مورد نظر قابل تعمیم به منظر سایر مناطق شهر اصفهان و هم چنین شهرهای دیگر با شرایط مشابه نمونه آزمونه خواهد بود.

    کلیدواژگان: بازآفرینی، منظر، منظر طبیعی، منظر تاریخی، زیرساخت های سبز
  • زهرا نوری، علی سلاجقه*، تقی عبادی، علیرضا مقدم نیا صفحات 471-483

    رسوبات به عنوان مخزنی برای ذخیره فسفر ‏عمل می کنند و تحت شرایط محیطی مختلف آن را انتشار و انتقال می دهند. اندازه ذرات رسوب یکی از فاکتورهای مهمی است که جذب فیزیکی ‏فسفر توسط رسوبات را تحت تاثیر قرار می دهد. در این مطالعه تاثیر اندازه ذرات رسوب و غلظت های مختلف بر روی جذب فسفر توسط رسوبات ‏رودخانه ی کرج مورد بررسی قرار گرفت. آزمایش های سنتیک جذب در غلظت های ‏mg/L23 و ‏mg/L‏ 100 محلول(‏KH2PO4‎‏)و دو غلظت رسوب ‏gr/L‏ 1 و ‏gr/L‏ 2 انجام شد. با توجه به آزمایش های جذب، ظرفیت جذب فسفر توسط رسوبات با افزایش اندازه ‏ذرات رسوب، کاهش می یابد. همچنین نتایج نشان دادکه مقدار جذب فسفر(‏P‏)در واحد جرم رسوبات با اندازه های مختلف، با افزایش غلظت اولیه ‏فسفر افزایش می یابد. در غلظت ثابت جذب شونده(‏C0‎‏)، مقدار جذبP‏با افزایش غلظت رسوب از 1 به 2 گرم رسوب،افزایش می یابد و در این مطالعه ‏تقریبا 5/1 برابر می باشد. تغییر غلظت رسوب نیز با افزایش مقدار جایگاه های فعال جذب روی رسوبات منجر به افزایش جذب فسفر می شود. استفاده از ‏معادله های شبه مرتبه اول و شبه مرتبه دوم برای توصیف سنتیک جذب فسفر نشان داد که معادله شبه مرتبه دوم با داده های آزمایشگاهی تطابق ‏بهتری دارد و پیش بینی خوبی را از میزان جذب انجام داده است. ‏

    کلیدواژگان: رسوب، اندازه ذرات، جذب فسفر، سنتیک جذب، رودخانه کرج
  • ارزیابی شاخص مقاومت به آلودگی هوا در سه گونه درختی توت سفید، آسمان دار و بید مجنون در چند منطقه از کلان شهر تهران
    اعظم سلیمی*، حامد دادخواه آغداش صفحات 484-500
    پراکنش آلاینده های سمی و سرطان زای ناشی از حمل ونقل وسایل نقلیه و دود حاصل از کارخانه های صنعتی ازجمله عوامل عمده آلوده کننده هوا در شهر تهران به شمار می آیند. یکی از راهکارهای مقابله با آلاینده های هوا، کاشت درختان مقاوم در معابر عمومی و جاده هاست. مقاومت گیاهان نسبت به آلاینده های هوا توسط شاخص مقاومت به آلودگی هوا(APTI) اندازه گیری می شود و افزایش این شاخص نشانه مقاومت بیشتر گیاه به آلودگی هوا است. در این پژوهش، APTI در سه گونه درختی توت سفید، آسمان دار و بید مجنون در اواخر فصل تابستان سال 1396 ارزیابی شد. بدین منظور از 4 منطقه کلان شهر تهران اعم از مناطق میرداماد، پونک، انقلاب و آزادی (مناطق9،6،5،3شهرداری) نمونه های برگی جمع آوری گردیدند. با انجام سنجش های بیوشیمیایی همچون اندازه گیری مقادیر اسید آسکوربیک و کلروفیل کل به کمک دستگاه اسپکتروفتومتر و تعیین pHعصاره های برگی و اندازه گیری محتوای نسبی آب در برگ های درختان موردمطالعه، شاخص APTI محاسبه شد. نتایج حاصل از این بررسی نشان داد که درخت توت سفید با شاخص APTI بالاتر (85/14) مقاومت بیشتری را نسبت به درختان آسمان دار (80/11) و بید مجنون (44/11) دارد. با توجه به این نتایج، به نظر می رسد کاشت این درخت جهت بهبود کیفیت هوای کلان شهر تهران در فصل تابستان و اوایل پاییز مناسب باشد.
    کلیدواژگان: شاخص مقاومت به آلودگی هوا (APTI)، درختان توت سفید، آسمان دار، بید مجنون، کلان شهر تهران
  • بررسی میزان آلودگی به آرسنیک در رسوبات دریاچه ارومیه و احتمال تاثیر آن بر سلامت جامعه انسانی
    مریم کاظمی، عاطفه چمنی*، ناصر آق صفحات 501-515
    با توجه به معرفی دریاچه ارومیه به عنوان یکی از کانون های ریزگرد در سطح جهان و پیامدهای خطرناک حضور فلزات سنگین در ریزگرد، هدف از این تحقیق، تعیین غلظت آرسنیک در رسوبات دو طرف میان گذر دریاچه و مقایسه آن با استانداردهای جهانی است. بدین منظور نمونه برداری رسوب از 12 ایستگاه در دو طرف پل در پاییز و زمستان 1396، از عمق30 سانتی متری رسوب صورت گرفت و غلظت آرسنیک هر نمونه اندازه گیری شد. شاخص های مولر و فاکتور آلودگی برای همه ایستگاه ها محاسبه گردید و نتایج با استانداردهای موجود مقایسه شد. میانگین غلظت آرسنیک در دو فصل(mg/kg 48/7) از میزان استاندارد رسوب (mg/kg 24/7) بیشتر است اما تفاوت معنی دار ندارد. شاخص های محاسبه شده، ایستگاه 4 و 11 در نزدیکی مصب رودخانه های منتهی به دریاچه در شرق و غرب را در طبقه آلودگی قابل توجه تا بسیار بالا و ایستگاه 6 در نواحی مرکزی دریاچه را در طبقه غیرآلوده قرار می دهند. استفاده از کودها، قارچ کش ها و حشره کش های و تخلیه فاضلاب می تواند عامل اصلی افزایش آرسنیک رسوبات باشد. ورود آرسنیک به چرخه غذایی، ریسک ابتلا به بیماری های مزمن و انواع سرطان ها در انسان را افزایش می دهد.
    کلیدواژگان: آرسنیک، دریاچه ارومیه، رسوب، ریزگرد
  • توسعه مدل ترکیبی برپایه شبکه عصبی جهت مدلسازی کیفیت هوای داخلی بازار تبریز به لحاظ ذرات معلق
    ندا کفاش چرندابی*، امیر غلامی صفحات 516-530
    با توجه به سپری شدن ساعات متعددی از زندگی هر انسان در فضاهای بسته، بررسی کیفیت هوای داخلی اماکن بسیار ضروری است. آلاینده های مختلفی در فضاهای بسته وجود دارند که از بین آنها، ذرات معلق توجه زیادی را به علت تاثیرات فاجعه بار بر سیستم تنفسی و حتی سیستم گردش خون به خود جلب کرده است. در این تحقیق با جمع آوری داده های مورد نیاز از فضاهای داخلی بازار تبریز کیفیت هوای آن به لحاظ ذرات معلق برپایه مدلهای مختلف شبکه عصبی مورد بررسی قرار گرفت. طول معابر، عرض معابر، تراکم نسبی جمعیت، جنس کف، وجود یا عدم وجود تهویه، تنوع کاربری، فاصله از خیابان های مجاور، بلندی سقف، دما و رطوبت نسبی در 1081 موقعیت مختلف اخذ شد که 86 نقطه از آنها دارای داده مربوط به آلاینده های ذرات معلق بودند و به عنوان داده ورودی برای ساخت شبکه بکار رفتند. پس از مقایسه شبکه های مختلف با پارامترهای گوناگون شبکه بهینه ساخته شد. سپس جهت افزایش کارایی مدل پیشنهادی، شبکه ساخته شده با طبقه بند ترکیبی ادغام گردید. نتایج به دست آمده از مدل پیشنهادی تحقیق به صحت 97.67 درصد برای پیش بینی کلاس آلاینده ها رسیده است.
    کلیدواژگان: آلودگی هوا، ذرات معلق، بازار تبریز، شبکه عصبی، طبقه بند ترکیبی
  • احیای اکولوژیکی بافت های فرسوده شهری از طریق شبکه های فضای سبز و باز به منظور ارتقای سرزندگی شهری براساس تئوری گراف و مدل کشش(مطالعه موردی: منطقه 9 تهران)
    معصومه محسنی فرد ناغانی، محمدرضا مثنوی*، لعبت زبردست صفحات 531-545

    بسیاری از کلان شهرها با پهنه های وسیعی از بافت فرسوده مواجه هستند. رشد بی رویه شهر تهران در دهه های اخیر و تغییر ساختار اکولوژی سیمای سرزمین اختلالات مهمی در فضای سبز بافت های فرسوده ایجاد نموده و موجب تغییر عملکرد و برهم خوردن تعادل اکولوژیک شهر شده است. برنامه ریزان و طراحان میتوانند با کاربست اصول اکولوژی سیمای سرزمین به تجزیه و تحلیل فضاهای سبز بپردازند و طرح های مناسبی برای توسعه و بهبود پیوستگی فضای سبز بافت فرسوده ارائه کنند. در این پژوهش از اراضی بایر برای ایجاد شبکه فضای سبز و دستیابی به سرزندگی شهری با کمک تئوری گراف، مدل کشش و استراتژیهای طراحی اکولوژیک منطبق با ساختار بافت فرسوده منطقه 9 تهران استفاده شد. منطقه دارای بافت متراکم و فرسوده بوده و عدم پیوستگی بین لکه های سبز موجود در آن مشهود است. نتایج پژوهش نشان می دهد منطقه 9، از نظر فضاهای سبز و باز قابل دسترس، دچار کاستی شدید و اندک فضاهای سبز موجود، فاقد پیوند اکولوژیک می باشند و ضرورت استقرار شبکه اکولوژیکی مناسب در بافت فرسوده این منطقه وجود دارد تا مفاهیمی مانند ظرفیت تحمل طبیعی، ظرفیت سازماندهی، پایداری اکولوژیکی که از مهمترین اصول شبکه های اکولوژیک است قابل دستیابی باشند.

    کلیدواژگان: احیای اکولوژیکی، شبکه اکولوژیکی فضای سبز، تئوری گراف، مدل کشش، بافت فرسوده شهری منطقه 9 تهران
  • تبیین الگوی مداخله در زیرساخت های سبز شهری با هدف ایجاد تاب آوری اکولوژیک شهری با تاکید بر تغییرات اقلیمی (نمونه موردی: محله یوسف آباد شهر تهران)
    المیرا شیرگیر*، رضا خیرالدین، مصطفی بهزادفر صفحات 546-560

    زیرساخت های سبز شهری، در تقلیل اثرات تغییرات اقلیمی در شهرها موثر بوده و باعث ارتقاء تاب آوری اقلیمی می گردند. یکی از بیشترین تاثیرات تغییرات اقلیمی را میتوان در شهرها و به ویژه در محله ها یافت. ارائه راهکارهایی در مقیاس محله، به منظور مواجهه با تغییرات اقلیمی ضروری به نظر می رسد. 3سوال اصلی: ارتباط بین زیرساخت های سبز شهری و مفهوم تاب آوری اکولوژیک از نوع اقلیمی در شهرها چگونه است؟ چگونه می توان از طریق زیرساخت های سبز یک محله تاب آور به تغییرات اقلیمی داشت؟،کدام ویژگیهای زیرساخت های سبز (کمی-کیفی) می توانند در رسیدن به و سنجش کیفی تاب آوری اقلیمی موثر باشند؟ الگوی مناسب مداخله در زیرساخت های سبز در مقیاس محله جهت افزایش تاب آوری اکولوژیک از نوع اقلیمی، کدام است؟بدین منظور، مطالعات کتابخانه ای در حوزه کلمات کلیدی و بستر نظری موجود انجام گردید و الگویی کمی-کیفی از روش مورد کاوی و بازدید میدانی به حیطه آزمایش گذاشته شد. با جمع آوری اطلاعات پایه و تحلیل آنها با نرم افزای GIS و بررسی عکس هوایی یوسف آباد تهران این الگو بر این منطقه منطبق گردید و ویژگیهای موثر زیرساخت های سبز در ارتقاء و سنجش تاب آوری ، تعیین گردیدند.

    کلیدواژگان: زیرساختهای سبز شهری، تاب آوری اکولوژیک شهری، تغییرات اقلیمی، محله یوسف آباد شهر تهران
  • تعیین سهم منابع انتشار هیدروکربن های نفتی هوپان و استران در منطقه بندر انزلی- جنوب غرب دریای خزر
    علی عظیمی*، علیرضا ریاحی بختیاری، روما تاولر صفحات 561-575
    در این مطالعه منابع اصلی هیدروکربن های نفتی در جنوب غرب دریای خزر (شهر انزلی) و سهم آن ها در انتشار این ترکیبات، با استفاده از انگشت نگاری شیمیایی و تحلیل های کمومتریکس و آنالیز کروماتوگرافی گازی- طیف سنجی جرمی مورد بررسی قرار گرفت. به طوری که ترکیبات ترپان، هوپان های کاتاژنتیک و استران در نمونه های رسپتور محیطی شامل غبار خیابانی، رسوبات معلق رواناب های شهری ، آب رواناب و رسوبات سطحی رودخانه ها و بندر انزلی و همچنین در منابع اصلی هیدروکربن های نفتی شامل اگزوز خودروها، تایر، آسفالت، روغن موتور، بنزین و گازوئیل مطالعه گردید. نتایج انگشت نگاری شیمیایی و تحلیل های کمومتریکس نشان داد که بخش عمده هیدروکربن های مورد بررسی در نمونه های غبار خیابانی، رواناب های شهری و برخی از نمونه-های رسوبات رودخانه ای ناشی از منابع اصلی پیشنهادی است، در حالی که این ترکیبات در بخش عمده ای از نمونه های رسوبات رودخانه ای و بندر انزلی، ناشی از منابع اصلی پیشنهادی نبودند و آنها احتمالا منابع آلاینده دیگری را غیر از 6 منبع پیشنهادی دریافت می نمایند. نتایج این مطالعه همچنین نشان داد که سهم آسفالت و تایر اتومبیل ها در انتشار هیدروکربن های نفتی در نمونه های رسپتور مورد مطالعه از سایر منابع بیشتر بوده، در حالی که روغن موتور اتومبیل ها کمترین سهم را در انتشار هیدروکربن های نفتی در بین منابع مورد مطالعه، داشته است.
    کلیدواژگان: آلودگی نفتی، غبار خیابانی، رواناب شهری، انگشت نگاری شیمیایی، تحلیل کمومتریکس
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  • Mahmoud Ahmadi *, Abbasali Dadashiroudbari Pages 379-394

    Introduction The assessment of air pollution has become one of the increasing global concerns and has a significant impact on climate and environment. So far, various strategies for controlling and managing air pollution have been presented, which are widely used in air quality monitoring for air quality measurement indicators. One of the most important indicators in measuring air quality is PM2.5. These particles make up 60 to 70 percent of the total particle and play a significant role in radiative forcing induction through the absorption and diffusion of sunlight and, as it has been said, also greatly reduce the air quality and public health. In recent years, several studies have been carried out based on air quality measurements and PM2.5 observations based on urban pollution. With the launch of satellites and continuous improvement in data retrieval technology, PM2.5-related studies have become more dynamic. The method of data retrieval of PM2.5 based on satellite data during long-term statistical periods, especially for areas where no measured data is available, can be of great help to climate studies and air pollution. The AOD derived from satellite data can be very useful for PM2.5 monitoring, which will be of great importance when developing countries such as Iran are not available in land-based data. Or they do not have a decent time distribution. The precise estimation of PM2.5 involves the application of surface parameters, geographic data and local meteorological data, which leads to the development of more sophisticated models such as multiple regression models and nonlinear models. The method of data retrieval of PM2.5 based on satellite data during long-term statistical periods, especially for areas where no measured data is available, can be of great help to climate studies and air pollution. The aerosols optical depth (AOD), derived from satellite data, can be very useful for monitoring PM2.5. This is important when it is not available in countries with development such as Iran, land data or they do not have a good time distribution. This study, using SeaWIFS, MISR and MODIS data, evaluates the long-term (2016-1998) PM2.5 in the western and southwestern atmosphere of Iran. Materials and methods The study area of this study is West and Southwest of Iran including five provinces of Kurdistan, Kermanshah, Hamedan, Ilam and Khuzestan. In this study, PM2.5 hourly data from air pollutants from a collection of stations from the State Environmental Protection Agency was received. To calculate the aerosols optical depth (AOD), three data sources of SeaWfis, MISR and MODIS were used for long-term data. Finally, for calculating the average annual PM2.5 satellite, we used Geographic Weighting Regression (GWR) method and PM2.5 was calculated with spatial resolution of 0.01 arc for west and southwest of Iran. The GWR is a statistical method that allows spatial mapping in predictor coefficients of a relationship (predictive variable of response) based on linear regression and allows us to use the spatial structure of both predictor variables and its coefficients. Results and discussion The estimated PM2.5 data validation was calculated using two indices Coefficient of determination (R2) and Root Mean Square Error (RMSE) for Abadan and Ahwaz stations, and the results showed that the PM2.5 value was estimated using data The SeaWifs, MISR and MODIS sensors have good performance in the west and southwest of Iran. Three sensors SeaWifs, MISR and MODIS have shown a similar pattern in the amount of aerosols in the area, so that the Ilam and Khuzestan provinces exhibit maximum AOD, and the widest latitude, the AOD is decreasing. The spatial distribution of PM2.5 concentration during the period from 1998 to 2016 indicated that PM2.5 concentrations in the west and southwest of Iran showed that there was a distinct spatial pattern with strong changes in the whole region. Khuzestan province showed maximum PM2.5 levels between 1998 and 2016, which is significantly higher than other provinces. After the province of Khuzestan, southern parts of the province of Ilam have shown the maximum PM2.5. The average PM2.5 concentration in the west and southwest of Iran is 12.25 μm/m3; the Khuzestan province can be considered a unique region in Iran, due to the high concentration of desert dust transported to this region of the country, the maximum amount of PM2.5 has shown. Minimum AOD value for three sensors was investigated in Khuzestan province, east of Kermanshah province and Lorestan. This significant difference in the amount of aerosols can be due to several demographic variables, complex topography, meteorological factors such as lower wind speed, high relative humidity and precipitation, distances from dust sources, and eventually vegetation. Due to the fact that a large part of the Zagros Range, which has a height of more than 4,000 meters, prevents the influx of dusty aerosols into the area. Also, large areas of Zagros are well covered with vegetation. As a result, complex topography with appropriate vegetation and low population density and significant human inactivity in the mentioned areas are reasons for the lower amount of aerosols compared to the provinces of Ilam and Khuzestan. Trapped desert dust under the meteorological patterns plays a regional role in reducing and increasing PM2.5 in the studied area. Another factor that can greatly influence the variability of suspended particles in the studied area is due to the complexity of the topography and the pathway of many common systems (such as the Sudanese and Mediterranean systems), which is the wetting phenomenon, which can underestimate the precision of the combined and estimated data Impact. The assessment of the location of the cities with the highest increase has shown that most of these cities are located in the border regions or are not far from the border areas of the country. These changes are clearly indicative of the apparent impact of the dust burden on the country and the increase of suspended particles in the atmosphere. Also, the relationship between AOD and PM2.5 can be changed with meteorological parameters such as the depth of the mixture layer, relative humidity, air temperature and wind speed. Conclusion The Aerosol optical depth (AOD) in the west and southwest of Iran from south to north and west to east has shown a decrease; the high AOD in the studied area relative to the absorption of Wet deposition, the formation of secondary aerosols and contamination Caused by regional dust storms and human factors (such as combustion of fossil fuels), especially in the areas adjacent to the western borders of Iran, which accumulates particles in these areas due to their proximity to high dust sources. The particles matter in the atmosphere of the provinces located in the west and southwest of Iran have shown that the amount of entrained air entering Iran under dusty storms is the most important factor in the increase of PM2.5 in this region of Iran. The maximum particulate matter were calculated in two provinces of Khuzestan and Ilam, the effect of dust storms has a significant role in this increase. The evaluation of the PM2.5 variation over the course of the period from 1998 to 2016 has shown that between 1998 and 2012, the increasing amount of PM2.5 and subsequently showed a decrease, a change from an inactive diet to a volatile active period. Also, the coefficient of variation of PM2.5 during the studied period showed that more than 30 percent of the particles in the border regions and the route of storm surges to Iran have been. The coefficient of variation of PM2.5 during the studied period showed an increase of more than 30% of the particles in the border regions and the route of storm surges to Iran, so that Saqez, Mehran, Masjed Soleiman, Dehloran and Kermanshah showed the maximum gradient of the computational process.

    Keywords: Estimation of particulate matter, particulate matter (PM2.5), Aerosol optical depth (AOD), remote sensing, west, south west of Iran
  • Ali Beheshti Ardakani, Amir Hesam Hasani *, Homayon Ahmad Panahi, Amir Hosein Javid, Elham Moniri Pages 395-412

    ABSTRACT This study investigates the performance of modified Nano tin(IV) oxide sorbent in oil pollution removal from sea water. This sorbent synthesized in two stages: synthesizing tin(IV) oxide nano particles and modifying its surface, using (3-mercaptopropyl) trimethoxysilane and grafting of N,N-dimethylacrylamide-allyl butyl ether copolymer on it. The resulting sorbent was characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, and scanning electron microscopy, then evaluated for TPH adsorption from environmental water samples. Total Petroleum Hydrocarbons (TPH) is considered as water pollution index and measured by Gas Chromatography. Batch experiments were conducted to evaluate the effect of analytical parameters of pH, contact time, and temperature. The optimum pH was 5 and contact time was 10 minutes. The capacity of the sorbent was 11.46 mg g-1. Results showed good accessibility of the active sites. The equilibrium adsorption data of TPH sorption onto grafted nano-tin(IV) oxide were analyzed using the Langmuir and Freundlich isotherm models. The adsorption data was modeled as pseudo-first-order and pseudo-second-order kinetic equations. The results show that adsorption followed by the Langmuir isotherm and the pseudo-second-order model. The sorbent removed more than 80% of the TPH from the water solution samples. Key words: Oil removal, TPH removal from water, Nano tin oxide, Modified sorbent 1. Introduction Oil pollution has several long-term effects on environment and economy. Cleaning oil pollutions and oil spills are very expensive, and among different methods for removing oil from water, such as physical methods, adsorption, and biological treatment, adsorption methods are widely applied. Nano-materials have interesting characteristics that make them promising sorbents in aqueous solutions. Surface modification of nano-materials by grafting of polymer chains enhances their structural properties and sorption capacity. This study focuses on removing oil pollutions from water by synthesizing an efficient nano-sorbent. Tin(IV) oxide (SnO2) nano-particles were synthesized using the co-precipitation method; after modification by 3-mercaptopropyl trimethoxysilane, they were grafted with N,N-dimethylacrylamide and allyl butyl ether. The performance of this grafted synthesized nano-sorbent was then evaluated for use in oil adsorption from water. 2. Materials and Methods 2.1. Synthesis of SnO2 nano-particles grafted with hydrophobic groups 2.1.1. Synthesis of nano-SnO2 At the first stage, SnCl2.2H2O (116.3 g) was dissolved in 250 ml distilled water to prepare 2 M SnCl2.2H2O solution. Then, 2 M NH3 solution was added gradually to the SnCl2 solution while stirring at room temperature (25°C) to reach pH = 7. The slurry was stirred for 2 h and then filtered and dried. 2.1.2. Polymer grafting A two-step method was applied for this stage. The first step was modification of SnO2 with 3-mercaptopropyl trimethoxysilane and second step, Graft polymerization, was grafting the N,N-dimethylacrylamide (DMAA)- allyl butyl ether (ABE) copolymer onto the modified SnO2. First step SnO2 nano-particles were silylated using an anhydrous solution of 5% 3-mercaptopropyl trimethoxysilane in 1,4-dioxane. A mixture of SnO2 nano-particles (3 g), 1,4-dioxane (2.5 ml) and 3-mercaptopropyl trimethoxysilane (47.5 ml) was refluxed for 24 h at 100°C. The solid precipitate was filtered and washed several times with 30 ml of 1,4-dioxane and dried under vacuum in a desiccator over dry calcium chloride. Second step In this stage, a mixture of modified SnO2 nano-particles (3 g), ethanol (30 ml), ABE (4 ml), DMAA (1 ml) and 2,2'-azobis (2-methylpropionittrile) (0.1 g) was prepared and the mixture was refluxed in a nitrogen atmosphere for 8 h at 65°C. The grafted particles were filtered and washed with ethanol and water and then dried. This poly-grafted nano-SnO2 with (ABE-co-DMAA) is named AD-GNS. 2.2. Oil pollution index assessment Total Petroleum Hydrocarbon (TPH) is considered as an index assessment of oil pollution in water, and this index is measured by Gas Chromatography (GC). 2.3. Batch adsorption experiments A set of solutions (each 200 ml) containing crude oil and water were prepared and their pH values adjusted to the optimum value of 5. Then each 200 ml solution was divided to two 100 ml solutions, and one of them considered as standard solution for initial TPH assessment. Then desired dosage of AD-GNS was added to other 100 ml solution and it was shaken for 1 hr. The sorbent was filtered, and the suspensions were centrifuged at 7000 rpm for 5 min and the clear supernatant and the standard solution were analyzed using a GC-FID. 2.4. Parameters optimization for sorption and isotherm study In this study, the effects of initial pH, contact time, and adsorbent dose were investigated to obtain the optimize condition for adsorption of oil on AD-GNS. Then adsorption isotherms, Langmuir and Freundlich isotherms, and adsorption kinetic models, the pseudo-first-order and the pseudo-second-order, are applied to investigate the mechanism of adsorption and efficiency of oil removal. 3. Results and Discussion The AD-GNS was characterized by FTIR, TEM and SEM. FTIR of the SnO2 nano-particles confirmed the presence of Sn-O-Sn and O-H. A peak at 1091 cm-1 caused by the Si-O band in the FTIR of the modified SnO2 nano-particles confirms the modification with 3-mercaptopropyl trimethoxysilane. The presence of CH2, CH, and OH are confirmed by FTIR. The IR spectrum of the AD-GNS was compared with that of the modified SnO2nano-particles. Two additional bands appear at about 1103 and 1641 cm-1 that correspond to C-O and C=O, respectively. TEM showed spherical agglomerated micro-particles with diameters of less than 100 nm, and SEM confirmed that particle size for AD-GNS was ranged from 30 to 50 nm. The degree of oil sorption by pH value was determined using the batch equilibration technique at pH values ranging from 3 to 8. Fig. 1(a) shows the effect of pH on the sorption of oil. Evidently, adsorbate uptake depended on solution pH and the maximum adsorption was achieved at a pH of 5. The effect of contact time on the adsorption of TPH was investigated at different initial concentrations of oil and an optimized pH of 5. The AD-GNS amount was constant during this stage. As seen in Fig. 1(b), oil uptake was rapid at the start of the process in response to the huge surface area with functionalized and available active sites, but then slowed. The adsorption rate became constant as the active sites were covered with xylene and equilibrium was reached. As seen, at lower initial concentrations, adsorption was faster, and 10 minutes was usually enough for complete sorption. This reflects that active sites on the sorbent are easily accessible. The effect of adsorbent dose is also evaluated by adding different dosage of AD-GNS to solutions with constant TPH value and pH=5. The results are shown in Table. 1. For better interpretation of the results of Table. 1, Langmuir and Freundlich isotherms, can be determined, and results are listed in Table. 2. As shown in Table 2, RL =0.02, and it is in the range of 0-1, which shows highly favorable adsorption. The maximum adsorption capacity of AD-GNS for complete monolayer coverage on the surface (qmax) is 11.61 and it confirms the very high capacity of the synthesized sorbent. To analyze the data and evaluate the mechanism of adsorption and efficiency of oil removal, two adsorption kinetic models, pseudo-first-order and pseudo-second-order, are applied, and proves that the pseudo-second-order model presents the adsorption kinetics better. 4. Conclusions A new sorbent synthesized by a two-stage method. Although the synthesis of the sorbent is simple and economical, it is time-consuming. The optimum pH for oil removal from water by the sorbent was 5, and contact time was 10 minutes. The capacity of the sorbent was 11.46 mg g-1. Results showed good accessibility of the active sites. The equilibrium adsorption data of TPH sorption onto grafted nano-tin(IV) oxide were analyzed using the Langmuir and Freundlich isotherm models. The adsorption data was modeled as pseudo-first-order and pseudo-second-order kinetic equations. The results show that adsorption followed by the Langmuir isotherm and the pseudo-second-order model. The sorbent removed more than 80% of the TPH from the real water solution samples.

    Keywords: Oil removal, TPH removal from water, Nano tin oxide, Modified sorbent
  • Somayeh Arghavani, Hossein Malakooti *, Abbasali Aliakbari Bidokhti Pages 413-429

    Urban green spaces are essential parts of the city's configuration which can be expanded in the urban areas in the forms of parks or gardens, and green urban structures such as green roofs or green walls. The green areas around the city are usually constructed in the form of Green Belts and forest parks. In new decades, land use/ land cover alterations have remarkably reduced the urban green spaces which cause environmental concerns such as biological pollutions, increase in surface runoffs and greenhouse gases, and the phenomenon of dust and the urban heat island. Studies on the role of urban greening on air quality in different regions have shown that the structure, physical characteristics and vegetation types can be the decreasing factors of air pollution, but in special circumstances, they may show adverse negative impacts. Indeed, on one hand, they can affect the wind and temperature fields, as well as the atmospheric emission patterns and the transmission of pollutants and natural ventilation over the city, and on the other hand, by releasing organic volatile organic compounds (VOCs), they may accelerate the rate of ozone production. Therefore, proper selection of plant species and management of urban green space design are substantial and complicate issues in urban management programs. One of the proposed strategies to control the excessive expansion of cities, prevention of marginalization and population growth in cities is the development of the Green Belt. According to the definitions, the Green Belt is a green striped borderline in the margins of the city that has numerous environmental impacts, such as beautification of the urban landscape, stabilization of the soil and preventing the entrance of the aerosols and dust to the city center. According to related studies, the area and density of the Green Belt play major roles in changing the concentration of atmospheric pollutants due to sedimentation and deposition processes. The history of the Green Belt Development Project of Tehran backs to about 40 years ago and its completion is one of the priorities of the urban management programs. It is predicted that the area of Tehran Green Belt reaches more than 40,000 hectares so it is expected to show significant changes on the micro-climate of the city. Therefore, in this study, the role of the Green Belt Development of Tehran on weather parameters such as wind and temperature fields, relative humidity, surface heat flux and planetary boundary layer height (PBLH), as well as the atmospheric concentration of atmospheric gas pollutants (SO2,NO2,CO and O3) are studied, using coupled Meteorological-Chemical numerical model (WRF-Chem). WRF-Chem numerical model (version 8.3) coupled with the Noah Land Surface Model and the UCM urban canopy model is used for numerical simulations. The National Centers for Environmental Prediction (NCEP) global forecast system (GFS) reanalysis data on a 1˚×1˚ grid are used for the atmosphere and soil initial and boundary conditions. MOZART (Model for Ozone and Related chemical Tracers) data are applied for boundary conditions of domain 1 and initial conditions for 4 domains in the chemistry section. The 2005 version of carbon bond chemical mechanism (CB05) and the MADE (Modal Aerosol Dynamics Model for Europe) aerosol scheme are used for simulations. Model of Emissions of Gases and Aerosols from Nature (MEGAN) is used for biochemistry. Anthropogenic emission inventory is produced by PREP-CHEM-SOURCES preprocessor from RETRO (REanalysis of TROpospheric chemical composition) global data. Tehran updated emission inventory is mapped over the global anthropogenic data in the fourth domain and emissions are introduced to the model through two separate times (wrfchemi_{00z,12z}_d04). The control case is representative of the current state of land use in the city of Tehran. Four early summer days (18-21 June 2016) with the cloudless condition, calm wind and without precipitation are selected for the simulations. In the next stage, the green belt scenario is performed to reproduce the meteorological and chemistry parameters and the results were compared with the control case. Findings show that green belt development on the eastern and southeast boundaries of the city has reduced the temperature (about 2.5°C) and increased relative humidity within the city (about 7% at nighttime and 4% at daytime) which confirms the positive role of this green area in improving environmental comfort level. Also, the cooling effect of this green space in the borders of the city is noticeable. Furthermore, this urban green approach reduces the wind speed and changes the wind direction over the region. This factor, as well as the observed decrease in PBLH (nightly changes in the center of the city are -200 meters and in the northwest and southeastern margins are -300 and -500 meters, respectively), have caused the accumulation of polluted air in the city center. Particularly during the night, the green band of the northern margin of the city has reduced the influence of local mountainous winds to the city and a significant reduction in wind speed in the city center, which has a negative impact on the status of air pollution and heat island in this area. Changes in the wind direction in the western border of the city prevents the outflow of polluted air and entrance of the clean air which has a negative effect on the concentration of industrial pollutants in this part of the city. Further studies in this area are needed in other seasons, especially in winter, with significant levels of pollution. Based on the results obtained in this study, low-density plants with limit height which have less unwanted impacts on wind flow and natural ventilation of the city, are proposed to be used in Green Belt project of Tehran Metropolis.

    Keywords: Green Belt, Thermal Comfort, Air Quality, WRF, Chem, SLUCM, Tehran Metropolis
  • Sahel Shahizare, Islam Karami *, Mojtaba Rafieian Pages 431-451

    Introduction Principles and criteria related to the quality of the environment and the relation between this quality and its cultural, historical and social contexts in the design of residential complexes are ignored, which also reduces the satisfaction of residents from the complexes. The purpose of this research is to improve the quality of residence in the residential complexes through contextual components. Accordingly, in the first part of the article, by reviewing the literature in this field, different dimensions of context and quality of residence in residential complexes are explained. Then, in the research methodology, the tool and the method of testing the theoretical model in some selected residential complexes in Ardabil city and the method of data analysis are described. Further, the findings are analyzed and the results of the study are presented. According to the main hypothesis of the research, it is likely that the application of contextual components will improve the quality of residence in the design of residential complexes in Ardabil, as well as the sub-assumptions of the research including: (1). The components of the terrain and external conditions of the complexes have the most impact on the quality of residential complexes and the quality of residential units. (2).The natural component has the greatest impact on the quality of residence in the residential complexes of Ardabil. The present research seeks to answer the following main question: Does the application of contextual components improve the quality of residence in Ardabil’s residential complexes? Also, the following sub-questions: (1).Which components have the most impact on the quality of residential complexes and complexes in Ardabil? (2).Which subjects have the most impact on the quality of residence in the residential complexes in Ardabil? The context or contextual discussion is one of the topics that are of great interest today in the world. The lack of relation between implemented projects and environmental issues, especially in Iran, has led to issues such as inconsistency, identity crisis, and lack of utility and dissatisfaction with residence in residential complexes. So one of the solutions is to adopt a context-based design approach. There was no research on the study of the field of contextual factors affecting the quality of residential housing development in the residential complexes; therefore, not repeating the issue and the need for a new look at the residence issue would justify the necessity of this review. The present research can help policy and planning to design the deep and efficient architecture of residential complexes in accordance with the needs of residents. Materials & Methods The present research is descriptive-analytic in nature and time-consuming as a future-oriented cross-sectional research and is considered as a quantitative method in terms of the purpose of the applied research part. The primary information gathering tool in this study was a questionnaire based on various dimensions of the research variables (field components and quality of residential complex) to assess the residents' views of residential complexes in the new and central context of Ardabil city. Initially, the original study and pilot scale was in the form of a scale of five Likert options (1- very low, 2-low, 3- medium, 4- high and 5- very high). The target population of this study is residents of Ardabil’s residential complexes, which are selected by Cochran sampling method with a confidence level of about 6%, 240 residents of the complex. In order to determine the statistical sample, eight cluster models with observation and review of the writers, eight residential complexes named Negin Sarsotoun complex (with physical field), Abrovan complex (with physical, natural and historical context), Mansoorieh complex (historical and natural), Mahtab complex (Natural), Sabalan complex (physical, historical and cultural), Nastaran complex (physical and environmental), Vesal complex (physical and natural) and Aseman complex (physical) with different contexts were selected. In this study, four main components of contextualism, namely physical context, socio-cultural context, historical context and natural context are chosen as independent variables and quality of residential complex as dependent variable, and individual factors of gender, ownership, age groups, marital status and the length of stay as controlling factor. Cronbach's alpha coefficient was used for reliability of the questionnaire. The Cronbach's alpha coefficient was 0.889 for 23 questions about contextual components and quality of the residential complexes, which is a sign of the reliability of the questionnaire. To analyze the data of the questionnaire, Means-test and T-test and multiple regression analysis are used in the SPSS software. Finally, the path analysis model is mapped to three levels based on regression coefficients. Discussion of Results & Conclusions The results of individual factors affecting the quality of residence through contextualism showed that, as time passes and age increases, the mean of contextual components increases. There is also a linear relationship between the level of components and the level of education, and with the increase in the length of residence in the complex, the quality of residence and contextual increases. Also, with an increase in residence duration in the city, the average historical context increases. The results of the findings showed that the quality of residential complexes in Ardabil is moderate to high, where social quality has the highest score in terms of residence and the lowest score is related to physical quality. As expected, residential complex residence, in terms of participation, community and security, is an effective factor in increasing social quality of complexes. Also, the highest average quality of residential units is related to exterior conditions, to the internal conditions of the units such as light, brightness, visibility and landscape. On the other hand, in terms of impact, the quality of contextual component has the greatest impact on the quality of residential complexes and the external component of the units has the most impact on the quality of residential units in Ardabil. Therefore, the first sub-hypothesis of the research is also proved. Among the contextualism, the natural context (especially respect for nature and environment) has the most impact on the quality of residence, that is, the quality of residential complexes and also the quality of residential units in Ardabil. Therefore, the second hypothesis of the research is proved. The highest mean of contextualism is related to the physical context, and the lowest average is related to the historical context. In the historical context, which has the lowest score in terms of residence in the studied complexes, the least attention is given to the connection with the monuments that today are not getting much attention in the design of residential complexes, monuments and historical monuments, and this is the reason that the symbol dimension of the cultural context is also the lowest in terms of inhabitants. On the other hand, Pearson correlation test showed that in each of the eight complexes, the highest correlation coefficient was related to the quality of residence and natural context. Among the selected complexes, the highest correlation coefficient between the quality of residence and the physical context was found in in the Nestaran complex, and the highest coefficient of correlation between the quality of residence and the historical context was found in the Mansouriyeh Complex, which is located in the central-historical context of the city. Therefore, in order to improve the quality of residence in residential complexes, planners and architects and urban planners need to pay attention to the quality of the complex context (including environmental health, maintenance costs and lifestyle), as well as the external conditions of residential units (such as lighting and Green space), especially in the natural context, including respect for nature and environmental protection.

    Keywords: Contextual, Quality of Residence, Residential Complex, Residential Unit, Ardabil
  • Vida Rafiee *, Fariba Vahidzadegan, Roxana Abdollahi Pages 453-469

    1. Introduction The present cities are so far from sustainability indicators and living standards. At present, no balance is observed between urban networks and natural patterns while urban networks are more dominant over ecological networks. The presence of nature in the city is considered as a vital environment to enhance the quality of biological, environmental, and landscape characteristics. The question of this study was that due to the dense and worn-out texture of some urban areas like District 3 in Isfahan where the designing a green infrastructure network is impossible due to the lack of spatial openness such as green spaces and urban spaces, what will be the solution for the current problems and future developments? Green infrastructure is a response to modern human need for sustainable development and can be regarded as an approach focusing on the protection of natural environments and their performance as well as the human need results in a comprehensive framework for environmental, social, and economic sustainability results. In this regard, regeneration is a strategy which reorganizes the economic, social, and environmental structures, leads to the restoration of environmental quality or ecological balance, and combines them within the framework of sustainable development goals. In this approach, considering landscape is similar to a vast mosaic, identification of the disturbances created in the natural process of the inherent natural patterns forming such mosaics, regeneration and design through for restoring the patterns, streams, corridors and green networks. The goal of designing the green infrastructure of many activities is based on ecosystem and human health. *AUTHOR: EMAIL: F.VAHIDZADEGAN@YAHOO.COM In order to regenerate historical-natural landscapes, the current models in the field of green infrastructure planning were studied and reviewed and then in accordance with their criteria, the optimal natural-historical patch and corridors were selected. Then, the framework of strategic policies and actions in the areas of strengthening, protecting, improving and restoring the landscape was presented to enhance the quality of environmental life - landscape at the regional level after field observations in accordance with the criteria of quantitative and qualitative methods for urban green infrastructure matrix. 2. Materials and methods In this study, the combination of both quantitative and qualitative models was used with the regeneration of natural-historical landscape to increase the degree of reliability and efficiency. The studied area District 3 of Isfahan is located on the northeast part of central Isfahan in the old city of Isfahan. After examining the satellite images, the percentage of mass to space, the study of social-cultural problems, the amount of worn-out texture and its comparison with the standards and models of urban green infrastructure were used by examining the current potentials (including stream axis, etc.), this area was selected to regenerate the natural-historical landscapes and approach the naturalistic cities and sustainable development. Patch, corridor, matrix The structural elements of landscape are introduced as patch, corridor, and matrix based on Forman model. This model itself is part of AWOP model. patchs include urban parks, gardens, cemeteries, vacant lands, urban spaces, semi-private-public green spaces, etc., and corridors include rivers, canals, streams, linear parks, energy transfer paths, streets, etc. After analyzing the structural elements of landscape based on patch and corridor at the regional level, an appropriate pattern of green and open spaces network in an interconnected system at the regional level was presented. Natural- historical landscape regeneration In this method too, based on Forman model, the valuable natural- historical patchs of the region were selected for regeneration and simultaneously used in the design cycle of green continuous network. AWOP Model This model identifies the landscape elements and presents solutions after overlapping the extracted layers. Based on this model, the small patchs and corridors should be protected and then connected to larger patchs and corridors with ecological function to have a strong connection. This model is of a qualitative type and does not alone respond to the design of green infrastructure. For this reason, the patchs being selected in this method were determined with other quantitative and computational criteria through Gravity model. Then, the aforementioned layers were identified, extracted, and overlapped while the valuable patchs were highlighted and interconnected. Gravity Model Gravity model examines the ecological impact of patchs and corridors on each other based on the extent and distance between them and ultimately achieves the optimal matrix in terms of complexity, connection, and the ratio of manufacturer/user cost. After overlapping the layers in with the principles and criteria of AWOP model, the patchs and corridors were selected based on the criteria and at the same time the patchs which could be regenerated in the region and having common conditions with the model were selected. Finally, they were weighted and formulated based on the principles and criteria of Gravity model. The studied and measured items: 1. Weighing the selected non-historical patchs 2. Weighing the selected historical patchs 3. Studying the interaction of both non-historical patchs based on the extent of patchs and the distance between them 4. Studying the interaction of both historical patchs based on the extent of patchs and the distance between them 5. Valuing the selected natural- historical-traffical corridors based on ecological indicators 6. Weighing the scores of selected ecological corridors 3. Results Based on the physical, structural, functional, and other situations, several networks can be produced and evaluated in this model based on green network typology such as the combination of hierarchical and Beckman models. 4. Discussion and conclusion Cities have converted in such a way that the natural and historical layers at their surfaces have disappeared into dense urban masses. As a result, the city has suffered from lack of self-purification, climate change, and the spread of mental, physical and mental diseases. In this regard, the idea of the interconnected urban green infrastructure network is one of the raised strategies to achieve a balance between the natural and artificial environment in the city and the sustainable structure of the city. It should be noted that each of the above-mentioned methods (not only with a merely qualitative model and not merely a quantitative one) could not respond to the local needs of the region and urban management. Thus, by combining AWOP model and Gravity models, it is the best and most applicable model for responding to the research goals regenerating the past self-sustainable city. 5. Suggestions This method can also be generalized to other cities and towns with similar conditions to the sample under study such as worn-out, historical, natural textures, and so on. Based on the results, the large patch of Isfahan's Tabark Castle, which has been the oldest part of the city and the center of government in past times but has been neglected, at the same time the natural-historical landscape regeneration of the castle, that can work as the biggest ecological- landscape node in the central loop of hierarchical and Beckman patterns. Finally, some strategies can be presented separately for each zone in the framework of strategic actions in the domains of strengthening, preserving, improving, reparation and regenerating the natural and historical landscape.

    Keywords: Regeneration, Landscape, natural landscape, historical landscape, green infrastructure
  • Zahra Noori, Ali Salajeghe *, Taghi Ebadi, Alireza Moghadamnia Pages 471-483

    ‎1-Introduction Rivers are considered as one of the main sources of water supply for agriculture, drinking water ‎and industrial use. Water pollution is one of the most important problems in the world, especially in ‎developing countries (Bandpey et al., 2013). Transferring the suspended sediments and pollutants ‎into the outlet of the watersheds by runoff can be classified as an important reason for reducing the ‎quality of water systems (Blanco et al., 2010). Meanwhile, Phosphorus is one of the most important ‎nutrients in aquatic systems and plays an important role in the trophic state of water resources, ‎which need to be managed in order to prevent eutrophication. So, sediments are specified as a main ‎source and factor for the nutrients transferring to rivers, which have a significant impact on factors ‎such as light penetration and water temperature (Eder et al., 2010). Sediments may act as a ‎phosphorus sink due to certain physical, chemical and meteorological conditions that can release a ‎significant amount of phosphorus to the water column, which leads to various problems in water ‎resources (Fytianos and Kotzakioti, 2005). The release of soluble phosphorus in rivers is strongly ‎influenced by the interactions between phosphorus and suspended and bed sediments (House et al., ‎‎1995). Therefore, studying of characterizes of phosphorus adsorption by sediment is necessary in ‎order to better understand the interactions between phosphorus and sediments.‎ Several studies have been carried out on the effects of sediments and various adsorbents on the ‎adsorption of pollutants including heavy metals and etc. in Iran. But those only have focused on ‎the heavy metal adsorption, while nutrients such as nitrogen and phosphorus are also the main ‎source of contaminants in rivers. On the other hand, studying the effect of sediment particles on the ‎adsorption and transfer of nutrients including phosphorus has not been carried out using river ‎sediments and most of them focused on the adsorbents. Therefore, the purpose of this study is to ‎investigate the effect of sediment particles on the absorption and transfer of phosphorus and to ‎determine the kinetics of phosphorus adsorption using natural river sediments.‎ ‎2. Materials and methods‎ ‎ The natural ‎sediments under 15 cm surface sediment from the several points of the Karaj River were collected ‎and sent to the laboratory. In order to reduce the effect of other sediment components on the ‎physical absorption of phosphorus, all sediment samples underwent a pretreatment process to ‎remove a large number of inorganic, organic, metal ions from natural sediments particles. After ‎removing sediment contaminate, Grinding drum and sieve were used to size the sediment samples. ‎After the clean and sized preparation, four groups of different sediment particle sizes were ‎obtained (Meng et al., 2014) including D1 with size ( Phosphorus adsorption kinetics ‎ Absorption experiments were carried out at different concentrations in order to investigate the rate ‎of adsorption of sediment with time progression. Dried sediments samples (0.2 g) with different grain ‎size D1 to D4 were added in a series of 250-ml beakers with 100 ml phosphate solution (KH2PO4) at ‎various concentrations including 23 and 100 mg/L. Two initial phosphate concentrations were adopted, ‎‎23 mg/L for the low concentration and 100 mg/L for the high one. The pH values of the solutions were ‎maintained at 7.5 by adding 0.01 mol/L of NaOH and 0.01 mol/L of HCl. All reaction bottles were ‎agitated at a rotational speed of 190 r/min. The sample solutions were taken at different time (5, 10, ‎‎20, 30, 60, 120, 180, 240, 480, and 720 min) and centrifuged immediately at a rotational speed of 5000 ‎r/min for 10 min. The supernatant was immediately filtered through 0.45-ym Whatman GF/C filters for ‎phosphorus analysis. The total phosphorus concentration in the sediment samples was monitored ‎using the molybdenum-blue complex method with a UV/visible spectrometer at the wavelength of ‎‎780 nm (Murphy and Riley 1962). Each test was carried out three times, and the average results were ‎recorded if the results of the three tests varied within a certain range. The amount of P adsorbed onto ‎sediment was calculated as the difference in the concentration in the water phase at the beginning ‎and end of the experiment. The difference between the concentration of phosphorus in the initial and ‎final solution was considered to be equal to the amount of phosphorus absorbed (equation 1) ‎‎(Onyango, 2010).‎ Qe= ([(C_0-C_e )].V)/M (1) ‎ Adsorption (%) = (C_0-C_e)/C_0 ×100 (2) ‎ Where Qe is the amount of phosphorus absorbed in mg/g, C0 and Ce are, respectively, the initial and ‎equilibrium phosphorus concentration (mg/gL, V is the volume of solution, and m is the mass of ‎sediment (g).‎ The quasi-first-order adsorption kinetic equation, and quasi-second-order adsorption kinetic equation ‎‎(Chien and Clayton 1980) were used to model the adsorption kinetic process. They can be expressed, ‎respectively, as follows:‎ ‎ (3)‎‏ ‏‎ ‎‏ ‏q_t= q_e (1-e^(-k1t))‎ ‎ (4)‎‏ ‏‎ ‎‏ ‏‎〖 q〗_t=‎‎ q_e q_(ek_2 t)/(1+q_e k_2 t)‎ Where qe and qt is the amount of phosphorus adsorbed by the sediment sample at equilibrium and ‎time t (mg/g), k1 is the rate constant of the quasi-first-order equation (min-1), and k2 is the rate ‎constant of the quasi-second-order equation (g/(mg•min)).‎ ‎3. Discussion of Results‎ ‎ Migration and transformation of pollutants in the water environment depend on the adsorption ‎and desorption characteristics of interactions between sediment particles and surrounding water ‎‎(Wei et al., 2014). The dynamic adsorption process in different sediments showed that there were ‎clear differences in phosphorus adsorption in various particle sizes of sediment. The kinetic process ‎of the phosphorus adsorption appears to occur in three distinct stages: an initial fast adsorption stage, a ‎relatively gradual adsorption stage, and an eventual equilibrium state where the amount of phosphorus ‎adsorbed reaches a maximum. The evaluation of absorbed amount over time indicates that the rapid ‎stage absorption process and the highest absorption amount take place in the first 2 hours and its ‎concentration ranges from 0.04 mg/g to 0.2 mg/g at the concentration of 100 mg /l and from 0/02 to ‎‎0/16 mg/g at 23 mg/l concentration and tends to reaches the equilibrium level after 6 hours. ‎Compared to coarse-grained particles, fine-grained particles due to the large specific surface area ‎deserved large amount of phosphate adsorption. Particle with the diameter of 0.05 mm or ‎D1adsorbed much more phosphate than the other ones as it had the smallest size and largest ‎specific surface area. With time increasing, the corresponding adsorption kinetics curves became ‎flatter as the adsorption amount of phosphorus had the tendency to reduce, indicating that the ‎kinetic adsorption process was time-dependent.‎ ‎ Variation in the amount of P adsorption per unit mass of sediment at time t for different sediment ‎concentrations(S0) when the initial P concentration(C0)in the water phase was 100 mg L−1 ‎illustrates that the P adsorption amount increased with increasing sediment concentrations from 1 to ‎‎2 g and in this study, it is approximately 1.5 times. Rapidity of adsorption kinetics during the first ‎few minutes can be interpreted by the availability of a significant number of active sites on the ‎surface at the beginning of adsorption, compared to that remaining after a certain time(Mustafa et ‎al., 2010). ‎ Variation of qt over time (t) and its fitting with pseudo-first-order and pseudo-second order ‎equations for the four groups of sediment with different particle size can be seen in Fig.1. The ‎results of two kinetics models were applied the sorption kinetics of sediment samples showed that ‎the kinetics of P adsorption onto sediment are well described by the pseudo-second order model. ‎The quasi second-order equation has the highest correlation coefficient(R2)and it can be ‎concluded that the quasi-second-order equation provides the best representation of the kinetic ‎adsorption process.‎

    Keywords: Sediment, grain size, phosphorus adsorption, Kinetic adsorption, Karaj River
  • Air Pollution Tolerance Index (APTI) of three Tree species Morous alba L., Aillanthus altissima (Mill.)Swingle and Salix babylonica L. in different areas of Tehran city, Iran
    Azam Salimi *, Hamed Dadkhah Aghdash Pages 484-500
    Introduction Air pollution is one of the top environmental concerns and illness of human health (She et al., 2017). Experts concluded that contents of outdoor air pollution (emphasis particulate matter) have adverse effects to human health (Carvalho-Oliveira et al., 2017). Air pollution associated with lung cancer, cardio vascular systems that threat human health (Carvalho-Oliveira et al., 2017). In some countries, for instance in the China, air pollution is the fourth concern and death in this country (She et al., 2017) . Pollutants which are in urban areas respectively, P.M (2.5,10), ozone, SO2, NO, Pb, CO causes injure in plant leaves and effects the size of leaves and stomatal characteristic. The release of pollutants cause many threat for plants and other organisms. (Achakzai, Khalid et al. 2017). The Plants more resistance than of other organism (human, animal) for environmental pollutants. The APTI (air pollution tolerance index) value select plant species by their tolerance or sensitivity to pollution source by means of biochemical and physiological parameters (Achakzai, Khalid et al. 2017). leaf trees used for monitoring air quality and more affordable method in compared with traditional techniques(Carvalho-Oliveira et al., 2017) There are 22 air quality monitoring stations in Tehran city. According to air quality monitoring, P.M 2.5 is the main air pollutant that threats public health and other organisms (plants, animals) . Industrial factories, carcinogen and phytotoxic air pollutants that emitted from vehicle motor, use of low quality fuels (Benzene etc), lack of proper monitor for Air pollution are the main causes of Air pollution in Tehran. The current research was conducted with the aim of study of air pollution tolerance index of three tree species such ( Morous alba , Ailanthus altissima , salix babylonica ) in different areas of Tehran city . Material and methods The city of Tehran (35035 / N to 350 48/ N and 51 0 17/ E to 51 0 33 /E., area 800 km2, Iran) has 22 air quality monitoring stations. According to this stations, four sites selected for collection of three tree such as Morous alba, Ailanthus altissima, Salix babylonica, respectively Area 3(site1), Area5 (site2), Area6 (site 3) and Area9 (site 4). Leaf samples of three tree species with similar heights and age were collected on Monday, September 17, 2017. Ten leaves of each plants collected and stored in sealed plastic bags and kept in a portable ice- box and transferred to the lab for physiological and biochemical analyze. In the lab four biochemical parameters such as total chlorophyll, ascorbic acid (was measured by spectrophotometer), Extract pH leaf samples, relative water contents evaluated (Achakzai, Khalid et al. 2017). The air pollution tolerance index of the plant species is determined using the formula given by Singh and Rao (1983): APTI = ([A (T + P)] + R) / 10 In this formula, A is the content of leaf ascorbic acid in mg.g-1Fw; T, total leaf chlorophyll content in mg g-1Fw, P, pH of leaf extract, and R is the percentage of relative water content of leaf. According to the criteria provided by Pandy et al. (2015), which is confirmed by many researchers, plants with APTI values ranging between 17-30 (tolerance), 13-16 (average), 13 (sensitive), and plants with APTI 1> are very sensitive (Pandey , Pandey et al. 2015). Results and Discussion Total chlorophyll content (TCH ) Results of measuring of chlorophyll contents indicated that the total chlorophyll content of the Morus alba was highest (site 4) in the selected sites. While Ailanthus altissima at site 1 had the lowest chlorophyll contents. In this study, total chlorophyll contents in three tree species studied were ranged between 2.52 to 7.10 mg.g-1 Fw. Chlorophyll is a photosynthetic pigment which indicate photosynthetic activity and dependent to factors such as age of plant species, environmental conditions, pollution level (Katiyar and Dubey, 2001; Ninave et al., 2001; Achakzai et al., 2017). Morus alba at polluted sites 4 and 3 (according to Tehran's air quality monitoring data) showed the highest chlorophyll content (7.1 and 6.4), while Salix babylonica, Ailanthus altissima at site 1 and 2 have the lowest chlorophyll content (3.26 and 52.2). According to capabilities of each tree, the response of three trees in sites 1 and 2 was less, but at sites 3 and 4 responded to air pollution by increasing the contents of Total chlorophyll. Therefore, all three trees have increased their chlorophyll content against air pollution, but the Morus alba tree has been more successful than other trees. The results of this study are consistent with the results of other researchers that plants with higher chlorophyll content are high resistant to air pollution (Shannigrahi et al., 2003; Prajapati and Tripathi, 2008; Rai and Panda, 2014.( Ascorbic acid Results of measuring of Ascorbic acid concentration indicated that Ascorbic acid concentration of the Morus alba was highest (site 4) in the selected sites. While Salix babylonica at site 2 had the lowest Ascorbic acid concentration. In this study , Ascorbic acid concentration in three tree species studied were ranged between 3.66 to 7.80 mg.g-1 Fw. Ascorbic acid levels in selected trees increase in contaminated areas(site 3,4). The results of this study are consistent with the results of other researchers, with high amount of stress, increase antioxidants such as ascorbic acid ((Mächler et al., 1995; Krishnaveni, 2013; Kaur and Nayyar, 2014). Relative Water Content (RWC) Results of measuring of Relative water contents indicated that Relative water contents of the Morus alba was highest (site 2) in the selected sites. While Ailanthus altissima at site4 had the lowest Relative water contents. In this study, Morus alba showed the highest RWC at site 3,4 , its value was even higher than the other trees. which is a sign of a better response of the Morus alba to contamination. The results are consistent with the results of other researchers(Ritchie et al., 1990; Chaves et al., 2003). pH leaf samples Results of measuring of pH leaf samples indicated that pH leaf samples of the was highest (site 3) in the selected sites. While Ailanthus altissima at site2 had the lowest Relative water contents. In this study pH leaf samples in three tree species studied were ranged between4.9 to 7.4. Morus alba showed a better resistance than to the other tree species by trying to neutralize the alkaline pH. Ailanthus altissima and Salix babylonica, showed Acidic pH content (approximately 5.5). Air Pollution Tolerance Index (APTI) Results of measuring of APTI Values indicated that APTI Value of the Morus alba was highest (site 4) in the selected sites. While Salix babylonica at site4 had the lowest Relative water contents. According to the results of this study, White mulberry seem to be a good alternative to planting in Tehran and Tolerant to seasonal air pollution (summer and early autumn). In order to recommend the planting of this tree in different areas of Tehran, it is necessary to consider other criteria such as the water need for this tree, its transpiration rate, resistance to insects, such as aphids and whitefly. Also, its seedlings to test the maximum tolerance to air polluted in the appropriate greenhouses.
    Keywords: Air Pollution Tolerance Index (APTI), Morus alba, Ailanthus altissima, Salix babylonica, Tehran city
  • The ssessment of arsenic contamination in Urmia lake sediments and its effect on human health
    Maryam Kazemi, Atefeh Chamani *, Naser Agh Pages 501-515
    Introduction
    Unfortunately, in the past decade, the growing trend of various human activities, despite the benefits, has brought major environmental challenges to humans, among which, aquatic ecosystems are exposed to serious risks due to their higher developmental capabilities. The physical and chemical parameters of water are constantly changing, and therefore are not suitable indicators for water quality monitoring. Sediments are the most important part of lithosphere, since they are final accumulation site for potentially toxic elements in aqueous ecosystems and in maybe could be a source of water pollution. Therefore, sediments are suitable indicators for environmental pollution. One of the most important international wetlands in Iran is Urmia lake. However, human and natural factors have caused problems in the lake in 2 past decades. Urmia lake is one of the largest saline lakes in the world, comparable to the Great Salt Lake in the United States. The Urmia Lake bridge, is the largest and longest bridge in Iran, and crosses Lake Urmia, connecting the provinces of East Azerbaijan and West Azerbaijan. This project was completed in November 2008. The construction of the causeway for the bridge, along with other ecological factors, will contribute to the drying up of Lake Urmia, turning it into an inland salt marsh, and adversely affecting the climate of the region. The 1,276 meters’ gap in the causeway is not wide enough to permit and adequate flow between the two portions of the lake. Therefore, this study aimed to evaluate the arsenic contamination in Urmia Lake sediments and the possible reasons for the arsenic pollution in this valuable ecosystem.
    Materials and Method
    Based on distances and covering the study area, 12 stations on both sides of the highway, has been selected. Sediment samples were collected in autumn and winter at a depth of 30 cm and arsenic concentration of each sediment sample was measured. The sediment samples were collected by plastic shovel and placed in thick polyethylene plastic bags. Finally, all samples were placed in ice and transferred to the laboratory in less than 24 hours and stored in the freezer. For acidic digestion of the samples, the samples were kept at ambient temperature to freeze and dry. After the samples lost their initial moisture at laboratory temperature, The Geo-Accumulation Index: The Igeo index was calculated based on equation 1: Igeo = Log2 [Cn/(Bn*1.5)] (1) Cn: The measured concentration of examined metal in the sediment. Bn: The geochemical background value in the Earth’s crust: 6.8 for As, 14.8 for Pb and 0.1 for Cd The value “1.5” is introduced to minimize the effect of the possible variations in the background values which might be attributed to lithological variations in sediment. Contamination degree(Cd): This method is based on the contamination degree(Cd) of each pollutant. Cd = Mx/Mb (2) Mx is metal concentration in the sample and Mb is background value in the Earth’s crust.
    Results
    The total average concentration of arsenic in the lake is 7.48 mg /kg. The average concentration of arsenic at stations 4 and 11 is significantly higher than the ISQGs standards (7.24 mg/kg). Table 1. Muller and contamination degree results Station Igeo(autumn) Igeo(winter) Cd(autumn) Cd(winter) 1 -1.52 -0.12 1.99 1.38 2 -1.35 -2.12 2.24 0.34 3 0.14 -1.31 6.28 0.60 4 0.14 0.94 6.25 2.87 5 -0.58 -0.44 3.79 1.10 6 -5.68 -4.25 0.11 0.08 7 -0.98 -0.36 2.88 1.17 8 -1.19 -0.41 2.49 1.13 9 -0.07 -0.11 5.43 1.39 10 -0.21 -0.37 4.91 1.16 11 0.07 0.22 5.96 1.75 12 -0.1 -0.99 5.31 0.75
    Discussion
    The average concentration of arsenic at station 4 in the central area of the lake and station 11 in the east of the lake is significantly higher than the global standard, which is about station 11, due to the estuaries of the rivers that put a significant load of pollutants to the lake. Station 4 is also located near the estuary of the western riverside. The results of the chemical indices also put stations 4 and 11 in the remarkable to very high contaminated category. Among all the stations, station 6 has the least contamination of arsenic, which can be due to being located in the central area of the lake and away from pollution sources. More than 20 permanent and seasonal rivers and 49 river streams cross into Lake Urmia, and each year it adds a considerable amount of suspended matter with high absorption capacity. Which can be the main source of heavy metals concentration, including arsenic. Agricultural activities and especially fertilizers, herbicides, fungicides and insecticides containing arsenic. Also, the discharge of urban and rural sewage into the lake and the rivers can be a major factor in increasing of arsenic in sediments. In a study by the Remote Sensing Research center of Sharif University of Technology, some areas of the Urmiah lake, have been identified as potential dust centers. the center of the 2 in the east of Lake Urmia has overlap with east stations in the present study, especially Station 11. According to studies, the wind direction dominates from Lake Urmia towards the city of Tabriz in winter. Therefore, in the case of drought in Urmia Lake, high-concentration arsenic and other heavy metals can have unfortunate consequences for the health of the population in affected areas. Due to the closure of the Urmia Lake, all the pollutants are accumulated in the lake. For this reason, the continuous monitoring of river water entering the Urmia Lake can be very helpful in understanding the changes in ecological status of Lake. Urmia Lake is located in Azerbaijan as the industrial-agricultural heart of Iran. Lack of standard system for wastewater treatment, use of fertilizers, herbicides, fungicides and insecticides containing arsenic in the agriculture and finally discharge of urban and rural wastewater drainage caused by leaching of land. Lake farming as well as the effluent of nearby factories into the lake and rivers leading to it can be a major contributor to the increase in arsenic in the sediments. Urmia Lake is one of the most international wetlands also 105 important bird areas(IBA) of Iran. One of the most important values of Urmia Lake National Park is its habitat suitable for wildlife, migratory birds and aquatic life. Urmia Lake is habitat to many aquatic birds as wintering, summering and inbreeding habitat. Heavy metals can accumulate in kidney, liver, muscle, bone, feather, blood and eggs of birds. Various studies have shown that weight loss also reproductive, behavioral and nutritional disorders in birds are due to heavy metals. Inorganic arsenic can cause muscular dysfunction, slowness, falls and other symptoms in birds. Arsenic transfer in the form of arsenobetaine and dimethylarsinic from the female to the eggs. In addition, the negative impact of sediment heavy metals on the abundance and density of organisms as well as on the morphological characteristics of organisms have been proved. Thus, increasing the heavy metals contamination such as arsenic in sediments, can be an alarm signal for the continued generation of birds and other aquatic organisms in the lake. Then, monitoring of the rivers, prevention of overuse of fertilizers and pesticides, preventing industrial and agricultural effluents and municipal wastewater from discharging to the lake, can be used to reduce the pollution load of this valuable ecosystem. Keywords: Arsenic, Sediment, Urmia Lake, Particulate matters (PMs)
    Keywords: arsenic, Sediment, Urmia Lake, Particulate matters (PMs)
  • A hybrid model based on neural network for indoor air quality modeling of Tabriz bazaar in terms of particulate matter
    Neda Kaffash Charandabi *, Amir Gholami Pages 516-530
    The term of neural network has evolved to encompass a large class of models and learning methods. They interpret input raw data through a kind of machine perception, labeling or clustering models. They help to group unlabeled data according to similarities among the example inputs, and they classify data when they have a labeled dataset to train on. The neural networks consist of many layers. The layers are made of nodes. A node is just a place where computation happens, loosely patterned on a neuron in the human brain, which fires when it encounters sufficient stimuli. A node combines input from the data with a set of coefficients, or weights, which either amplify or dampen that input, thereby assigning significance to inputs with regard to the task the algorithm is trying to learn. These input-weight products are summed and then the sum is passed through a node’s so-called activation function, to determine whether and to what extent that signal should progress further through the network to affect the ultimate outcome, say, an act of classification. If the signals pass through, the neuron has been “activated.” A node layer is a row of those neuron-like switches that turn on or off as the input is fed through the net. Each layer’s output is simultaneously the subsequent layer’s input, starting from an initial input layer receiving your data. Pairing the model’s adjustable weights with input features is how we assign significance to those features with regard to how the neural network classifies and clusters input. Ensemble methods aim at improving the predictive performance of a given statistical learning or model fitting technique. The general principle of ensemble methods is to construct a linear combination of some model fitting method, instead of using a single fit of the method. Ensemble classifier has two common
    methods
    Bagging and boosting that they are non-Bayesian procedures. They can be used to improve the accuracy of Classification & Regression Trees. Boosting and bagging are two ensemble models capable of squeezing additional predictive accuracy out of classification algorithms. When using either method, careful tuning of the hyper-parameters should be done to find the best balance of model flexibility, efficiency & predictive improvement. Bagging uses a simple approach that shows up in statistical analyses again and again — improve the estimate of one by combining the estimates of many. Bagging constructs n classification trees using bootstrap sampling of the training data and then combines their predictions to produce a final meta-prediction. In this way, boosting creates successive base classifiers that are told to place greater emphasis on the misclassified samples from the training data. Like bagging, the results from all boosting base classifiers are aggregated to produce a meta-prediction. Compared to bagging, the accuracy of the boosting ensemble improves rapidly with the number of base estimators. Boosting method has many different algorithms that Least Squared Boosting (LSBoost) model was used to improve prediction model in this paper. Discussion of Results &
    Conclusions
    In the first step, for implementing and evaluating the research’s suggested method, Tabriz bazaar was chosen as the world’s biggest, most important and most complicated covered spaces. As the most important reasons for this choice the large dimensions of this historical bazaar, its complicated structure, presence of a wide range of tradespeople and different occupiers in bazaar, citizens’ and tourists’ referral all year long can be mentioned. Then different information related to Tabriz bazaar’s various passages and buildings including Passage’s length, passage’s width, proportional population density, surface material, presence or absence of ventilation, user’s diversity, distance from nearby streets, roof’s height, temperature and proportional humidity was recorded via field observation. Afterwards training data were collected for neural network. This was done in 86 points with different conditions with the help of a Japanese sensor named Pocket PM2.5 sensor which can evaluate PM2.5 and PM10 pollutants in the range of 0-999 (μg/m^3 ). Collected data for both of the pollutants were classified based on the present standards and place’s conditions in four healthy, medium, warning and dangerous classes and was shown by one to four tags. Given that determining parameters like the number of hidden layers, the number of neurons, the number of replications, the kind of transferring and tutorial functions in neural networks’ utilization is very important and effective, to determine them optimally a code in matlab coding language was used that not only it checks all the feasible functions and the appropriate number for neurons and layers, but also it determines their best amounts. By making multilayer neural network it is possible to predict dispersion in various conditions of pollutants’ amounts. In this paper due to users’ requirement for noticing the pollutant’s class and increasing accuracy the Round operator was used for classificating the results to four classes one to four. Due to the low accuracy of the results, ensemble classifier was used to improve the network. LSBoost model of Ensemble algorithm with the help of 100 boosted decision trees has obtained very appropriate results for this paper’s case study with a learning rate of one (η=1). for performing the neural network in training and network creation phase, data were divided into three sections of train, validation and test data that the way of mean squared error’s convergency and result’s accuracy were evaluated for each of the PM2.5 and PM10 pollutants. Efficient network was choosen by convegency’s speed, performance and accuracy. Due to the implementation the best network for PM2.5 pollutant was determined by two hidden layers (first layer with 9 neurons and transfer function of poslin and second one with 5 neurons and transfer function of tansig) with traincgb’s train data and general accuracy of 97.67% and MSE of 0.385. Also for PM10 pollutant with a hidden layer containing 4 neurons, transfer function of tansig and train function of trainlm with the general accuracy of 97.67% and MSE of 0.2779 was obtained. Traincgb function of Conjugate gradient backprogation with Powell-Beale restarts and trainlm of Levenberg Marquadrat algorithm is a combination of Gauss-Newton and gradient descent which uses the ability of both algorithms and has a high speed in training. It should be noted that in addition to the aforementioned networks, the Ensemble classification algorithm was run on this paper’s data which was resulted to accuracy of 67.44% for PM10 and to accuracy of 68.60% for PM2.5 that indicates the optimality of the compositional approaches used in this study. In other words by using combinational algorithm Ensemble and backpropagation multilayer neural network, the accuracy of results have been improved about 30%. Then based on the collected data in different conditions, the training was done for PM2.5 pollutant with the help of Newff-Ensemble neural network and for PM10 with the help of Feedforward-Ensemble network and prediction was done for other 995 locations of bazaar and PM zoning map was prepared. Based on these maps it is clear that most of the center zones of Tabriz bazaar has appropriate air quality. Some sections of bazaar including bazaarche shotorban, bazaarche yakhchal, chaharsog sadegieh, bazaar dalaleh zan bozorg, raste bazaar sadegieh, karvansarayeh shazdeh bozorg, dalan khan and bazaar jambor ha were in 4th class because of particulate matters and attendance of people who suffer respiratory disorders. Based on collected data for this study and by checking the results of this paper’s proposed model, four criteria Passage’s length, proportional population density, presence of ventilation, user type have been much more effective in increasing particulate matters’ class . So due to the obtained results from this study, areas which are located in dangerous class, effective and serious solutions should be done. For example related to the construction of these areas, modern or classic ventilation systems can be installed to improve the quality of bazaar’s indoor air.
    Keywords: Air pollution, particulate matter, Tabriz Bazaar, neural network, Ensemble methods
  • Ecological Reclamation of Distressed urban Fabric through Open and Green space Networks to Enhance the Urban Vitality Based on Graph theory and Gravity Modelling, The Case of District 9 Tehran City
    Masoomeh Mohseni Fard Naghani, Mohammad Reza Masnavi *, Lobat Zebardast Pages 531-545

    Ecological Reclamation of distressed urban Fabric through Open and Green space Networks to Enhance the Urban Vitality Based on Graph theory and Gravity Models, the Case of District 9, Tehran Authors Masoomeh Mohseni Fard Naghani1, Mohammad Reza Masnavi2 , Lobat Zebardast3 1. MSc. of Environmental Design, Graduate Faculty of Environment University of Tehran, Iran m.mohseni9190@gmail.com 2. Professor of Environmental Design, Graduate Faculty of Environment, University of Tehran, Iran 3. Assistant Professor of Environmental Planning Management, Graduate Faculty of Environment, University of Tehran, Iran, lzebardast@ut.ac.ir Abstract Introduction Many metropolitan areas face large urban decay and distressed areas within the city fabric. The rapid growth and unleashed urban development have led to ecological transformation and landscape fragmentation during the recent decades. These resulted in the damages to the structure and function of the urban green/open spaces especially in urban fabrics; and affected the form, function and hence sustainability of urban systems. In some metropolitan areas, the driving forces for the sustainable development and improvement of the physical structures of urban areas faced great challenges and deficiency in recent decades. The inner city or central neighborhoods like any other ecosystem will change and in some cases are losing their livability and quality of life during the time. This is due to the rapid unsustainable development and lack of proper urban open/green spaces which are essential for the residents’ quality of life. The process has consequently, turned into the neighborhoods’ ecological and environmental deficiency, and more decays in urban fabric. These are observed to be true in some part of Tehran city. The fundamental changes in the Tehran urban fabrics are seen through fragmentation of green patches and open spaces. Some researchers have suggested that the solution to this problem is to change the attitudes of planners to create or strengthen urban green infrastructures systems. Therefore, this paper utilizes the Graph theory and Gravity model, for the analyses of green space network. These, provide powerful tools and methods for analyzing and optimizing complex systems and evaluating the quality and quantity of urban green spaces, as well as developing efficient ecological landscape solutions for the efficiency, connectivity and continuity of the green space networks across the district 9 neighborhood. Materials and Methods In this research, the district 9, Tehran city is investigated as the case study. District 9 is one of the 22 districts of Tehran with an overall area of 1966 ha, which accounts for 2.9% of Tehran's total area. The urban landscape structural elements in urban regions include Kan river- valley in the west district which is among the most prominent structural elements of the urban landscape, and a series of small – medium green spaces. The urban landscape context in district 9 constitutes of dense, fine-grained, impermeable constructed surfaces. Landscape structural spaces include private green spaces, public green spaces, brownfield spaces renovation reserved lands. Other structural elements such as faults, high pressure power lines and accessing network are considered potential for the creation of green corridors in the area. Through review of the literature the research, is aimed at identifying and analyzing the urban green space network based on the ecological landscape design framework. By acquiring The land use map for the district 9, different information layers of the natural and artificial features were prepared including layers of river - valleys and watercourses, canal network, access network, fault, high pressure power lines, green areas, urban development lands and reserved lands for extracted, the overlapping layers and synthesis of data landscape elements, ecological network in district 9 was developed. First, at the macro level, the ecological effect of adjacent green spaces on each other in the distressed urban fabrics was calculated and variety of alternatives were presented to develop the most efficient green network in the distressed fabrics of district 9. At the micro level, the optimal connection route among the available routes were determined using the least cost route function. Weighted cost analysis for each node was performed separately by weighted cost analysis in GIS software. Subsequently, it was selected with the help of continuity indices in optimal network graph theory to develop green spaces in the distressed urban fabrics of district. The interaction between the nodes is evaluated using the traction model. The interaction is calculated using the following formula: G_ab=(N_a N_b)/(D_ab^2 )=((〖∑▒L)〗^2 LN(S_a S_b))/(L_ab^2 P_a P_b ) So that Gab interaction between nodes a, and b, Na and Nb are the corresponding weights, and Dab is the normalized cumulative impedance of the corridor between a, and b. Lab is the cumulative impedance of the corridor L between nodes a, and b, ΣL is the sum of the cumulative impedance of the corridor between nodes. Discussion The results suggest the greater the area of cross-spaces and the smaller the distance between them, the greater the ecological effect of cross-spaces. By calculating the amount of interaction between the spaces and prioritizing the links, the ecological network pattern in district 9, Tehran can be developed based on graph theory and gravity model. Then, alternatives are in the form of four proposed connection patterns. By comparing these connection patterns and network, the alternative 3 (Beckman Model) found to be the most efficient option for developing green space network for ecological reclamation, having 36 spaces and 37 links to improve continuity and achieve vitality in the distressed urban fabrics of district 9, Tehran. Figure 1 shows the alternative 3 (Beckman Model) based on graph theory and gravity model. Figure 1.The alternative3 (Beckman Model) in district 9, Tehran based on graph theory and gravity model. Some of the reasons for choosing this model are as follows: It can generalized and can be connected to the open and green spaces in adjacent areas in a repeatable pattern. The relative cost and number of connections compared to the other two models is such that it is responsive to users on the one hand, and responsive to green connections in the ecological network on the other hand. The project can improve the spaces and network corridor features by applying ecological principles such as maintaining the integrity and cohesion of the ecological landscape in distressed urban fabrics, which may help in strengthening the corridors and urban green infrastructure. Conclusion Many cities and urban areas are suffering from the expansion of distressed urban fabric in their central cores; these have led to the lack of green areas and open spaces which are essential for the urban sustainability and vitality. In this study, using concepts in graph theory and gravity modelling as well as cost analysis, the Beckman model was selected as the most efficient model in analyses and application of alternative solution in district 9 for connecting green and open spaces among four categories of connection between spaces. Each green/open spaces network will be designed according to the planner strategy, location, opportunities and constraints, taking into the account the ecological design principles of the site, as well as improving the quality of life in the distressed urban fabrics. Keywords: Ecological Reclamation, Distressed urban fabrics, Green space ecological network, Graph theory and Gravity model; District 9 Tehran. Main Subjects Landscape planning and design

    Keywords: Ecological Urban Reclamation, Green space ecological network, Graph Theory, Gravity Model, Distressed urban fabrics of District 9 Tehran City
  • Developing a pattern for intervention in urban green infrastructures to reach urban ecological resilience to climate change (Case study: Yousef Abad neighborhood in Tehran)
    Elmira Shirgir *, Reza Kheyroddin Pages 546-560

    Cities should be resistant to a wide range of shocks and pressures, including climate change (Leichenko, 2011).Therefore scholars and planners try to reduce the damages of natural disasters based on different approaches and patterns through the development of appropriate plans. One of these approaches is to investigate the resilience to natural disasters. Today, most natural disasters occur due to climate change. Climate change is a globally widespread phenomenon that is happening in the whole planet (Childers, 2015) and has created serious problems for humans and the environment. Resilience is a new concept that is mostly used when facing the unknowns and uncertainties such as climate change (Adhern, 2011). Resilience means that the urban system is able to withstand severe natural disasters without suffering from casualties, damages or loss of production capacity or quality of life (IPCC, 2007)). The resilience regarding the climate change reduction and adaptation is addressed in this study. Among the resilience types, what is considered in this research is the climate resilience that is a subcategory of urban ecological resilience. The climate resilience is the urban resilience to climate change (Carter et al., 2015). In this respect, the review of existing literature shows that few studies so far have addressed the concept of climate resilience, and most studies in the world and Iran, have only focused on the urban resilience and its assessment on the urban and regional scale. A very limited number of studies have addressed the resilience to climate change on other scales, especially the neighborhood scale. As a building block of cities, neighborhood is of great importance, and a resilient city can be achieved by a resilient neighborhood. On the other hand, one of the important factors influencing the climate resilience is urban infrastructure, especially green infrastructure. However, the main question and objective of this research is how to achieve a methodology or principles to examine the current situation of the infrastructure in cities to improve and ensure the climate resilience in the neighborhood by improving such situations. To answer the questions of this research, by selecting a case study and the GIS software to collect data about the status of vegetation and green infrastructure and to analyze the data based on the characteristics of green infrastructure’s resilience potentials and by providing the base and analytical maps, it was attempted to propose and develop a method for interfering with the quantity, quality and location of green infrastructure to increase climate resilience. Research Question: The main question here is: How are UGI and Climate resilience connected in cities? With which method or pattern can urban planners intervene urban green infrastructures in order to increase climate resilience in neighborhoods? And what are the effective urban green infrastructures resilience potentials? The main purpose here is to find a method to intervene UGI’s quality and quantity to increase climate resilience in neighborhoods. Also to find climate change adaptation strategies based on UGI and their effect on the city’s climate resilience in order to maintain, create and increase climate resilience. Research Goals: The general purpose of this research is to, extract principles of intervention or to find strategies for adaptation to climate change using green infrastructure (quality, quantity, their location, way of design and so on) and their impact on urban climate resilience and promoting climate resilience through the green infrastructure in city and neighborhood scale by enhancing the existing UGI and also by introducing climate resilience UGI and climate resilient green species for new urban projects. Terminology: Climate resilience in neighborhood scale Climate resilience includes the capacity of an independent unit or a group or organization to respond to climate change in a dynamic and effective manner, while still continuing to daily activities in an acceptable level. This feature includes the resistance to change, recovery after the shock, and reorganization to prevent the destruction of the system, that is the city (Dayland and Brown, 2012). In general, "climate resilience" is the urban resilience to climate change. Various literature has classified the climate resilience as a subcategory of urban ecological resilience. The studies conducted by Miller et al. (2009) emphasized the importance of urban infrastructure as an effective factor in creating climate resilience. However, the importance of green urban infrastructure is also considered, which is further discussed in the following. The climate resilience on the neighborhood scale includes the ability of the neighborhood in the physical-infrastructural, social, political and economic systems and the resistance and efficiency of settlements and buildings to tolerate the hazards of climate change to quickly return to the previous situation under these tensions and pressures, and to embrace and confront future threats. One of the greatest impacts of climate change can be found in cities, and especially in neighborhoods. As one of the most important urban segments, neighborhoods are no exception to these adverse effects. As a result, it is necessary to provide solutions on neighborhood scale for dealing with the climate change (Sasanpour et al., 2015). Urban green infrastructure in neighborhood Urban green infrastructure is a type of ecological social system that results from the interactions of various elements, especially humans. The components of green urban infrastructure can be considered a combination of open and closed spaces and a mixture of natural plant habitats, which are of great ecologic, social and economic significance. As a result, the proper design in these spaces can have a profound effect on the everyday life, and the resilient design is considered one of the most appropriate principles for the design of such spaces (Oliver, 2014). In general, green infrastructure includes green roofs, permeable green surfaces, green paths and streets, urban forests, public parks, neighborhood gardens, and urban wetlands (Demuzere et al., 2014).

    Methodology

    Iran is one of many countries that has been hit by climate change negative effects in the recent years. The main climate challenges that many big cities in Iran are facing are drought, air pollution, low annual precipitation, increasing temperature especially in summer, decreasing water resources quality, water shortage and so on. Based on these challenges the city of Tehran was selected as one of the big cities in Iran with the most climate challenges. The main climate challenges that Tehran is facing are, air pollution, water resources contamination and shortages, drought and extreme heat in summers. To find answers to the research’s main question, to reach the research goals and also to put to the test, the UGI climate mitigation strategies that were extracted from the literature review, ‘Yousef Abad’ neighborhood in Tehran was selected as the case study. The method used here was, studying various library and Internet sources, books for reviewing the existing literature. After this step, GIS, field studies and aerial photography, will be used as the main tool for developing different base and analytical maps such as: existing urban green and grey infrastructure maps, thermal maps of the selected neighborhood, building height and street width and direction maps, green species maps with the focus on their health and location. Also maps of existing patch, corridor and matrix will be developed and analyzed to measure climate resilience based on landscape ecology theories. After doing the above mentioned analysis, this research was able to achieve an extensible methodology to increase climate resilience through urban green infrastructure in the cities of Iran in the neighborhood scale to guarantee climate resiliency in the city scale. Also, by using landscape ecology language (Patch, corridor, matrix) as a method to interpret the existing eco-resilience conditions of green infrastructures, a method was introduced and also by using this method, the ecological characteristics of specific plants were analyzed and plants with better resilience potentials to drought, heat and air pollution were suggested for the study area. This was important characteristics of green infrastructures were introduced as factors for future analysis of ‘urban climate resilience’ in cities.

    Keywords: urban green infrastructure, Urban ecological Resilience, climate change, Yousef Abad Quarter of Tehran
  • Source apportionment of petroleum hydrocarbons hopane and sterane in Anzali port area- south of Caspian Sea
    Ali Azimi *, Alireza Riyahi Bakhtiari, Roma Tauler Pages 561-575
    Introduction This work is the first study where the contributions of major hydrocarbon sources are investigated in detail in south of Caspian Sea area. In other previous studies, the major source of polyaromatic hydrocarbons (PAHs) and other hydrocarbons in south Caspian Sea rivers and coasts was from petrogenic origin (Nemati Varnosfaderany et al., 2015; Shirneshan et al., 2016a; Azimi et al., 2017). However, the investigation of what are the main petroleum products entering into rivers and to southern coasts of Caspian Sea is still necessary. Hopanes and steranes are ubiquitous components of crude oil which are present in traffic-related sources (automobile exhaust, tires, asphalt, engine oil and fuels). They are present as homologs and stereoisomers of each other and their composition differ among crude oils depending on their source and maturation. Therefore, hopane and steranes profiles have been used to identify the sources of petroleum pollution (Zakaria et al., 2000, 2001; Shirneshan et al., 2016a, b; Volkman et al., 1997; Yunker and Macdonald., 2003; Maioli et al., 2010). Anzali is the most important port town in the southern Caspian Sea located in the north of Iran. This is one of the densest populated cities in Iran. Abundant rainfalls (1892 mm average annual precipitation) and crossing rivers inside the city accelerate the transport of street dust particles containing petroleum hydrocarbons into Anzali international wetland and rivers by surface runoffs (Kumata et al., 2000). In the present work, identification and distribution of the main sources of petroleum hydrocarbons in the street dust, runoffs and urban river sediments of different locations of Anzali port are investigated and they are related to automobile exhaust, tires, pavement asphalt, engine oil, gasoline and diesel possible sources. In addition, the contribution of each proposed source had apportioned by PCA and MCR-ALS chemometrics assays and fingerprinting diagnostic ratios. Materials and Methods Sample collection procedures Four type of receptor samples were collected and analyzed: street dust, runoff suspended sediment, runoff soluble water and river sediment samples. Street dust and Runoff samples were collected from the surface of all bridges on the urban rivers in Anzali city (8 bridges), and from the surface of the four streets with more traffic. Sampling was performed a day of sunny weather in September 2016 which was preceded by more than one week of sunny weather. Sampling of Runoff was performed in October 2016 during a rain of more than 10 mm after some days of sunny weather using a water sampler. Runoff samples were filtered by a vacuum pump which separates suspended solids from the water-soluble fraction. River sediment samples were collected from all urban rivers of Anzali city and from harbor (24 stations) utilizing Van Veen grab (50 cm×50 cm) in 3 replicates for every station. Six types of specific known pollution source samples were also sampled: tires, street pavement asphalt, gasoline, diesel, engine lubricant oil, and exhaust soot. Sample pretreatment procedure All solid phase samples including sediment, street dust, runoff filtered sediment, exhaust soot, tire and asphalt samples were extracted by the Soxhlet method. The Extraction and fractionation procedure is based on the method described in Zakaria et al. (2000). Petroleum hydrocarbons extraction from runoff soluble water was performed using liquid-liquid extraction, LLE, (Titato and Lancas, 2005; Okoli et al., 2011). Twenty milligrams of gasoline, diesel and engine oil samples were accurately weighed and dissolved in 2 ml DCM/n-hexane (1:3, v/v). These sample extracts were purified and fractionated using the same procedure as for the solid phase samples. Limit of detection (LOD) and limit of quantification (LOQ) of the analytical method were 0.13-23.06 and 0.41- 75.10 ng.g−1, respectively for all hydrocarbons. GC–MS analysis procedure GC/MS analyses were carried out by a gas chromatograph (GC, model 7890A, Agilent Technologies, PaloAlto, CA, USA) instrument coupled to a quadrupole mass spectrometer (MS, 5975C, Agilent Technologies, PaloAlto, CA, USA). Analytical standards were: 17a(H)-22,29,30-trisnorhopane, 17β(H), 21β(H)-hopane, diploptene (17β(H), 21β(H)-hop- 22(29)-ene), and 17α(H), 21β(H) hopanes. The sterane standard mixtures include 5α (H)-cholestane, 24-methyl- 5α (H)-cholestane, and 24-ethyl-5α (H)-cholestane. Perdeuterated n-tetracosane-d50 (m/z 66; relative concentration values) was used as standard (Yunker and Macdonald 2003; Harris et al. 2011). Recoveries were computed by spiking a known concentration of the SIS mixture (surrogate internal standard) to the sample followed by performing the whole analytical method. Recoveries of individual constituents of the spiked SIS were more than 85% for hopanes and steranes. Software All data analysis was performed under MATLAB (The Mathworks, MA, USA, 2014) numerical computing, visualization and programming environment. PLS Toolbox 7.0 (Eigenvector Research Ltd., Manson, WA, USA) and MCR-ALS Toolbox (www.ub.edu/mcr) were used for chemometric data analysis. Results and discussion Catagenetic hopanes composition is usually characteristic of petroleum sources, making them useful as possible molecular markers of petroleum pollution (Peters and Moldowan, 1993). The spatial distribution of catagenetic hopanes in the four type of samples, indicates the total amount of catagenic hopanes were higher in street dust and runoff (S and W) stations located in urban and populated areas with more traffic than in stations outside the city with lower traffic. Street dust particles in urban runoff act as a transport medium for pollutants such as PAH and petroleum markers (Brown and Peake, 2006; Herngren et al., 2006). Thus, these compounds arrive to the Anzali rivers and consequently to the coast of Caspian Sea and they are accumulated in river bottom sediments for a long time. In the case of river sediments also, the stations in runoff areas containing street dust and petroleum products, especially in the harbor area stations, had higher concentrations of catagenetic hopanes. Due to the closure of harbor by the artificial pier, pollutants accumulate in this area and settle in bottom sediments. In addition, in the harbor area, there are many ships and floats that release large amounts of petroleum hydrocarbons via their fuel and oil. Chemical fingerprinting To further investigate the distribution patterns of source-specific hydrocarbon markers, C23/C30 (ratio of C23 tricyclic terpane relative to 17α,21β(H)-hopane), Ts/Ts + Tm (ratio of 17α-22,29,30- trisnorhopane relative to 17α-22,29,30-trisnorhopane + 18α-22,29,30-trisnorhopane), C29/C30 (ratio of 17α,21β(H)-30 norhopane to 17α,21β(H)-hopane), C31HS/C31H(S + R), C32HS/C32H(S + R), ΣC31_C35/C30 (ratio of sum 17α,21β(H)–C31 homohopane to17α,21β(H)–C35 homohopane relative to 17α,21β(H)-hopane), C28 αββ/(C27 αββ + C29 αββ) and C29 αββ/(C27 αββ + C28 αββ) ratios were calculated for all the receptor samples and also for the proposed known source samples. Results show that especially in street dust and runoff samples, the relative amounts and concentration patterns of various terpanes and steranes in the street dust and runoff samples were rather similar, showing that they may have been originated from the same common sources. On the contrary, river sediment samples were confirmed to receive inputs from other unknown independent sources. Source apportionment According to MCR-ALS analysis, asphalt, and tire had the highest contributions (40% and 23%) to petroleum hydrocarbons in the analyzed receptor samples, and therefore, from a quantitative point of view, these two sources should be considered to be the main sources of petroleum hydrocarbons in the receptor samples analyzed in this study. There was only a 7% of the total mass analyzed that could not be explained by the proposed receptor model. Conclusion Results of this work demonstrated that street dust particles are identified as a major transport medium of petroleum hydrocarbons pollution in urban runoffs. Hydrocarbons from petroleum products stick to street dust and discharge with runoffs to Anzali rivers, Anzali international wetland and then accumulate consequently at the bottom of sediments of the Caspian sea coast for a long time. The contributions of asphalt and tire known sources to petroleum hydrocarbon contamination sources were larger than from other possible investigated sources in the studied samples. Automobiles exhaust soot had also some more specific contribution. Engine oil had only a minor contribution among the studied known sources to the petroleum hydrocarbons.
    Keywords: petroleum pollution, street dust, urban runoff, chemical fingerprinting, chemometric analysis