Sorption of Arsenic from Aqueous Solution by Nanoscale Zinc

Abstract

In this study, nanoscale zinc particles were used for arsenic removal under batch experiments. The aims of the study were to investigate the suitability of nanoscale zinc particles for arsenite [As(Ш)] adsorption and an analysis of factors affecting As(Ш) adsorption efficiency. These nanoscale zinc particles can effectively remove As(Ш) from aqueous solution. Over 98% As(Ш) was removed within 90 min in a concentration of 0.56 mg·L⁻¹, with a 1.25 g·L⁻¹ dose of nanoscale zinc particles. The kinetics of As(Ш) adsorption followed the pseudo-first-order model with observed reaction rate constants (k _obs) of 0.0292 min⁻¹. Besides, the results demonstrated that the arsenic removal percentage was affected apparently by pH, the amount of nanoscale zinc, the initial concentration and arsenic species. Based on the result, nanoscale zinc particles can be used for remediating As-affected groundwater usually containing substantial As(III) without preoxidation of As(III) to As(V).

Keywords:

• Nanoscale zinc particles
• batch experiments
• removal
• arsenite [As(Ш)]
• adsorption

Acknowledgments

This work was supported by the Work Program from China Geological Survey (1212011120286), the Commonweal Project from the Ministry of Land and Resources P.R.C (200911015-05) and the Special Fund of Basic Fundamental Scientific Research from National Research Center for GeoAnalysis (201012CSJ02). The authors appreciate Professor Liu Fei for her helpful discussions and Qian Jianghao for assistance with the arsenic analysis.