کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
585268 | 1453188 | 2006 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Adsorption of cationic polyacrylamide onto sepiolite
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
بهداشت و امنیت شیمی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The adsorption of PAM onto sepiolite from aqueous solutions has been investigated systematically as a function of some parameters such as calcination temperature of sepiolite, pH, ionic strength and temperature. The adsorption of cationic polyacrylamide (PAM) increases with pH from 5.50 to 11.00, temperature from 25 to 55 °C and ionic strength from 0 to 0.1 mol Lâ1. The sepiolite sample calcined at 200 °C has a higher adsorption capacity than the other calcined samples. Adsorption isotherms of PAM onto sepiolite have been determined and correlated with common isotherm equations such as Langmuir and Freundlich isotherm models. The Langmuir isotherm model appeared to fit the isotherm data better than the Freundlich isotherm model. The physical properties of this adsorbent are consistent with the parameters obtained from the isotherm equations. The zeta potentials of sepiolite suspensions have been measured in aqueous solutions of NaCl and different PAM concentrations and pH. From the experimental results: (i) pH strongly alters the zeta potential of sepiolite, (ii) sepiolite has an isoelectric point at about pH 6.6 in water and about pH 8 in 250 mg Lâ1 PAM concentration, (iii) PAM changes the interface charge from negative to positive for sepiolite. Effect of temperature on adsorption has been quantified by calculating various thermodynamic parameters such as Gibbs free energy, enthalpy and entropy. The dimensionless separation factor (RL) has shown that sepiolite can be used for adsorption of PAM from aqueous solutions.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Hazardous Materials - Volume 134, Issues 1â3, 30 June 2006, Pages 211-219
Journal: Journal of Hazardous Materials - Volume 134, Issues 1â3, 30 June 2006, Pages 211-219
نویسندگان
Nalan Tekin, Aziz Dinçer, Ãzkan DemirbaÅ, Mahir Alkan,