Experimental study on adsorption of copper containing wastewater by modified attapulgite

The experiment of adsorption of copper containing wastewater by modified attapulgite was performed to study the adsorption performance, process, thermodynamics, kinetics and its influence factors of modified attapulgite on copper containing wastewater. The results showed that the adsorption efficiency of acid modified attapulgite increased by 38.61% under the condition of 1 mol/L HCl, which indicated that the acid modification could activate the pore structure in attapulgite so as to significantly improve the adsorption performance. The maximum removal rate of copper ions by attapulgite could be up to 87.57% at the optimum reaction conditions as follows: the initial copper ion concentration of 100 mg/L, at temperature of 20 ℃ and the dosage of acid-modified attapulgite of 6 g/L. The adsorption of attapulgite on the copper containing wastewater was in accordance with the first-order kinetic equation and the Redlich-Peterson isotherm equation, and the fitting correlation coefficients R ² were 0.929 and 0.984 respectively, indicating that the adsorption process of attapulgite could be classified as physical adsorption. With the initial concentration of copper ions increasing, the modified attapulgite has a good adsorption effect on copper containing wastewater.