کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4909506 1362624 2016 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Alkaline treatment of timber sawdust: A straightforward route toward effective low-cost adsorbent for the enhanced removal of basic dyes from aqueous solutions
ترجمه فارسی عنوان
درمان قلیایی خاک اره: یک مسیر مستقیم به جاذب مؤثر کم هزینه برای حذف رنگ های اساسی از محلول های آبی
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
چکیده انگلیسی

The present study assesses the ability of two low-cost adsorbents - timber sawdust (TS-OH) and its alkaline treated analog (TS-ONa) - to remove two basic dyes, namely, Methylene Blue and Methyl Green, from aqueous solutions. The presence of new functional groups on the surface of TS-ONa resulted in a dramatic increase of surface polarity and the density of sorption sites, thereby improving the sorption efficiency of the cationic dyes. The results obtained from the sorption characteristics have revealed that the sorption process for TS-ONa was uniform and rapid. The adsorption of cationic dyes reached equilibrium within the first 10 min of contact time and the treated material acts efficiently in a wide pH range of dye solutions. The extent of adsorption was measured through equilibrium sorption isotherms and analyzed using the Langmuir model. The monolayer saturation capacities for Methylene Blue are 694.44 and 1928.31 mg g−1 and for Methyl Green are 892.86 and 1821.33 mg g−1 for TS-OH and TS-ONa, respectively. Therefore, the chemically treated sawdust proved two- to threefold higher adsorption capacities of these dyes than those of the untreated analog. The exothermic nature of adsorption is demonstrated by a decrease of adsorption capacity with increasing temperature, and the negative value of free energy change indicated the spontaneity of adsorption. Desorption experiments with 1 M aqueous NaCl put into evidence that cationic dyes were completely desorbed from the matrices and the reusability of the TS-ONa matrix after three repeated cycles led to just a slight attenuation in its performance. These results show that alkaline treatment of a low value by-product of the timber industry leads to a powerful and efficient low-cost adsorbent, which may be used for the treatment of colored wastewaters.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Saudi Chemical Society - Volume 20, Supplement 1, September 2016, Pages S241-S249
نویسندگان
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