Abstract—In this study, natural common clays were used as raw materials to be modified with ferric and ferrous solutions to develop improved efficient and low cost adsorbents. The adsorbents (Raw Clay, Clay/FeSO4, and Clay/FeCl3) were investigated for arsenate removal from synthetic aqueous solution in batch studies with respect to contact time, solution pH, initial As(V) concentration, and temperature. The results showed that As(V) uptake was pH dependent and the high efficiency occurred in the acidic condition. The adsorption kinetic data were fitted well with the pseudo second order adsorption model. The estimated maximum adsorption capacity from Langmuir model was 0.44, 1.50, and 0.86 mg/g for Raw Clay, Clay/FeSO4, and Clay/FeCl3, respectively. The values of a dimensionless constant separation factor (RL) and the magnitude of the adsorption intensity (1/n) showed that As(V) was adsorbed favorably on all adsorbents. The thermodynamic parameters indicated that the adsorption is spontaneous and endothermic and an irregular increase of the randomness at the adsorbent-adsorbate interface during the adsorption.
Index Terms—Natural common clays, adsorbent, adsorption, arsenate.
Borano Te, Boonchai Wichitsathian, and Chatpet Yossapol are with the School of Environmental Engineering, Institute of Engineering, Suranaree University of Technology, Nakhon Ratchasima, Thailand (e-mail: te.borano@ yahoo.com, boonchai@sut.ac.th, chatpet@sut.ac.th).
Cite:Borano Te, Boonchai Wichitsathian, and Chatpet Yossapol, "Modification of Natural Common Clays as Low Cost Adsorbents for Arsenate Adsorption," International Journal of Environmental Science and Development vol. 6, no.11, pp. 799-804, 2015.