کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
582365 | 1453166 | 2009 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Zn(II) adsorption from synthetic solution and kaolin wastewater onto vermicompost
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موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
بهداشت و امنیت شیمی
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چکیده انگلیسی
The adsorption of Zn(II) from both synthetic solution and kaolin industry wastewater by cattle manure vermicompost was studied. The adsorption process was dependent on the various operating variables, viz., solution pH, particle size of the vermicompost, mass of vermicompost/volume of the Zn(II) solution ratio, contact time and temperature. The optimum conditions for Zn adsorption were pH 6.0, particle size of â¤250 μm, 1 g per 10 mL adsorbent dose, contact time of 4 h and temperature of 25 °C. Langmuir and Freundlich adsorption isotherms fit well in the experimental data and their constants were evaluated, with R2 values from 0.95 to 0.99. In synthetic solution, the maximum adsorption capacity of the vermicompost for Zn2+ ions was 20.48 mg gâ1 at 25 °C when the vermicompost dose was 1 g 10 mLâ1 and the initial adjusted pH was 2. The batch adsorption studies of Zn(II) on vermicompost using kaolin wastewater have shown the maximum adsorption capacity was 2.49 mg gâ1 at pH 2 (natural pH of the wastewater). The small values of the constant related to the energy of adsorption (from 0.07 to 0.163 L mgâ1) indicated that Zn2+ ions were binded strongly to vermicompost. The values of the separation factor, RL, which has been used to predict affinity between adsorbate and adsorbent were between 0 and 1, indicating that sorption was very favorable for Zn(II) in synthetic solution and kaolin wastewater. The thermodynamic parameter, the Gibbs free energy, was calculated for each system and the negative values obtained confirm that the adsorption processes are spontaneous. The ÎG° values were â19.656 kJ molâ1 and â16.849 kJ molâ1 for Zn(II) adsorption on vermicompost in synthetic solution at pH 6 and 2, respectively, and â13.275 kJ molâ1 in kaolin wastewater at pH 2.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Hazardous Materials - Volume 162, Issues 2â3, 15 March 2009, Pages 804-811
Journal: Journal of Hazardous Materials - Volume 162, Issues 2â3, 15 March 2009, Pages 804-811
نویسندگان
Cláudio Pereira Jordão, Raphael Bragança Alves Fernandes, Kamilla de Lima Ribeiro, Bruna de Souza Nascimento, Priscila Martins de Barros,