(623b) Effective Arsenic Removal From Aqueous Solution Using Rare Earth Element Based Sorbent

Zheng, Y. M. - Presenter, Natioanl University of Singapore
Chen, J. P. - Presenter, National University of Singapore

Contamination of Arsenic in the water is of serious concern because of its marked negative impacts to human health. In this study, arsenic species, including arsenate As(V) and arsenite As(III), removal from aqueous solution using a rare earth element based sorbent was investigated. To evaluate the adsorption performance of the sorbent, effect of pH on the adsorption of As(V) and As(III) was investigated, the pH at point of zero charge (pHzpc) of the sorbent was determined, as well as the adsorption isotherm and kinetics studies were carried out. The pH effect studies showed that, the optimal working pH range for As(V) adsorption is between 4 and 10, while the optimal working pH for As(III) is between 10 to 12. The pHzpc of sorbent was found to be around 7. The kinetics study showed that the adsorption of As(V) and As(III) onto the sorbent is faster than that of most of the reported sorbents. Results from isotherm studies demonstrated that the sorbent has outstanding maximum adsorption capacities of about 250 mg-As/g and 120 mg-As/g for As(V) and As(III) at optimal pH, respectively.