بررسی کارایی جاذب‌های پلیمری شبکه‌ای درحذف فلزات سنگین آب با استفاده از مطالعات ایزوترم جذب

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشیار، پژوهشکده کاربرد پرتوها، پژوهشگاه علوم و فنون هسته‌ای، تهران

2 کارشناس ارشد مهندسی شیمی، پژوهشکده کاربرد پرتوها، پژوهشگاه علوم و فنون هسته‌ای، تهران

چکیده

جاذب‌های پلیمری ابزار مفیدی برای حذف فلزات سنگین از محلول‌های آبی به‌شمار می‌روند. از آنجایی‌کهاستفادهاز مدل‌های جذب می‌تواند موجب پیش‌بینی و تسهیل ارزیابی این فرایند شود،لذا در این تحقیق به بررسی رفتارجذبی جاذب‌های شبکه‌ای شده کیتوزان، پلی‌وینیلالکل و ترکیب آنها )نسبت وزنی 1:1)به‌منظور حذف فلزات نیکل و منگنز از محلول‌های آبی، از طریق دو مدل جذب لانگمیر و دوبینین-رادشکویچ، پرداخته شد. جاذب پلی وینیل الکل با هر دو روش شیمیایی و پرتویی و سایر جاذب‌ها به‌دلیل عدم مقاومت کیتوزان به پرتو فقط به روش شیمیایی شبکه‌ای شدند. برای هر دو فلز، مدل لانگمیر تطابق بهتری با داده‌های آزمایشگاهی داشت. بیشینه ظرفیت جذب به‌دست آمده از مدل لانگمیر نشان داد که جاذب کیتوزان/پلی وینیل الکل از جذب بالاتری نسبت به جاذب‌های دیگر برخوردار است. بیشینه جذب توسط این جاذب63/52 میلی‌گرم بر گرم برای نیکل و 30/30 میلی‌گرم بر گرم برای منگنز بود و فلز نیکل بیشتر از منگنز جذب شد. همچنین، پلی وینیل الکل شبکه‌ای شده به روش شیمیایی، برای نیکل بیشینه جذب46/38 میلی‌گرم بر گرم و برای منگنزبیشینه جذب 23/19 میلی‌گرم بر گرم را داشت که نسبت به مقدار مربوط به نمونه شبکه‌ای شده به روش پرتوییبالاتر بود. درنهایت برمبنای نتایج حاصل از این مطالعه مشخص شد که میزان جذب در ارتباط با نوع فلز جذب شده، ساختار جاذب و روش شبکه‌ای کردن آن است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Using Adsorption Isotherm Studies to Determine Crosslinked Polymeric Adsorbent Performance in Heavy Metals Removal from Water

نویسندگان [English]

  • Nasrin Sheikh 1
  • Shohreh Kianfar 2
چکیده [English]

Polymeric adsorbents are useful tools for removing heavy metals from aqueous solutions. Adsorption models are efficient tools for accurate prediction and evaluation of the practical adsorption process in real situation. In this study, the two isotherms of Langmuir and Dubinin-Radushkevich models were employed to investigate the absorption performance of chitosan, PVA, and chitosan/PVA blend (with a weight ratio of 1:1) in the removal of Mn (II) and Ni (II) from aqueous solutions. The PVA adsorbent was crosslinked by both chemical and radiation methods while the others were crosslinked only chemically due to Chitosan’s lack of resistance to radiation. The results showed that the Langmuir model fitted the experimental data better than the Dubinin-Radushkevich one for both metals. The maximum adsorption capacity (qmax) of the Langmuir model showed that the PVA/Chitosan adsorbent had the best adsorption compared to other adsorbents, with 52.63 mg/g for Ni and 30.30 mg/g for Mn (evidently more Ni was absorbed than Mn). Also, maximum adsorption by the chemically crosslinked PVA was 38.46 mg/g for Ni and 19.23 mg/g for Mn, which exhibits a higher level than adsorption by the radiation crosslinked PVA The results indicate that absorption capacity depends on the type of adsorbed metal, absorbent structure, and the crosslinking method employed.

کلیدواژه‌ها [English]

  • Heavy Metals Adsorption
  • Crosslinking
  • Langmuir isotherm
  • Dubinin-Radushkevich Isotherm
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