Enhanced removal of bisphenol-AF onto chitosan-modified zeolite by sodium cholate in aqueous solutions.

The removal of bisphenol-AF (BPAF) from aqueous solutions onto chitosan-modified zeolite (Ch-Z) in the absence and presence of sodium cholate (NaC) was investigated. It was found that NaC significantly increased the adsorption capacity of Ch-Z for BPAF. At an initial concentration of 100 μmol/L, the removal of BPAF by adsorption onto Ch-Z with NaC was more than ninefold higher than without NaC, and the maximum removal was achieved at a Ch-Z dosage of 1g/L with a NaC concentration of 1.68 mmol/L. Besides, batch studies were performed to evaluate the effects of various experimental parameters on the removal of BPAF. Kinetic studies and adsorption isotherms indicated that the adsorption process of BPAF onto Ch-Z with NaC could be expressed by a pseudo second-order model and the Freundlich isotherm model, respectively. For the enhanced removal, an interaction mechanism was proposed involving the co-effect of BPAF and NaC adsorbed onto Ch-Z.