کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
148690 456421 2013 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Removal of organic contaminants from river and reservoir waters by three different aluminum-based metal salts: Coagulation adsorption and kinetics studies
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Removal of organic contaminants from river and reservoir waters by three different aluminum-based metal salts: Coagulation adsorption and kinetics studies
چکیده انگلیسی


• Adsorption and kinetics mechanisms of DOM using alum, HPAC and PACl were compared.
• The character of DOM did not affect the adsorption mechanism at various pH levels.
• The BET isotherm was the best fit model compared with Freundlich and Langmuir models.
• Modeling indicates that the DOM sorption mechanism is by multilayer formation.
• HPAC produced the largest floc sizes with potential best floc settleability.

Surface waters from two different sources, river and reservoir, with different dissolved organic matter (DOM) concentrations and characters were investigated for removals using three metal coagulants, alum, a high performance aluminum polymer (HPAC) and polyaluminum chloride (PACl). Jar tests were conducted with coagulation pH ranging between 5.5 and 8.5 and doses between 5 and 16 mgAl/L. The adsorption mechanisms of DOM onto Al hydroxide precipitates of the three coagulants were investigated based on Freundlich, Langmuir and BET isotherm models. Coagulation kinetics and floc formation were studied using a photometric dispersion analyzer (PDA). For the three coagulants tested, optimum DOM removal was achieved at a coagulant dose of 11 mgAl/L and pH 6 for both waters. The lowest coagulant dose (5 mgAl/L) removed most organics with apparent molecular weights of between 2000 and 10,000 Da for both waters. DOM adsorption is best described by the BET isotherm model, indicating that DOM sorption occurred through multilayer formation in an arbitrary distribution of adsorbed particles. PACl showed the highest DOM adsorption capacity, determined by the Freundlich model. By PDA analyses, the flocculation index, average growth rate and variance values from the use of HPAC were highest in comparison with alum and PACl. The study of the coagulation kinetics suggested that HPAC produced the largest and most heterogeneous floc sizes with highest settling rates.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Chemical Engineering Journal - Volume 225, 1 June 2013, Pages 394–405
نویسندگان
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