Various Treatment Technologies to Remove Arsenic and Mercury from Contaminated Groundwater: An Overview

摘要

Contamination of groundwater due to toxic heavy metals, such as As and Hg, is of international concern. In this paper, the technical feasibility of some technologies to treat metal-contaminated groundwater is reviewed. All data presented are quoted from the original sources. It is conclusively evident from the literature survey that low cost technology, like adsorption, can demonstrate excellent metal removal capabilities comparable to reverse osmosis. Due to chemical modification, adsorption using inexpensive materials, such as coconut husk carbon, can remove As(III) with metal adsorption capacity of 159 mg/g. This high adsorption capacity suggests that adsorption treatment technique is capable of reducing a residual arsenic concentration to 10 μg/l, which is the maximum discharge limit set by the U.S.EPA (Environmental Protection Agency). In spite of the availability of various technologies to treat metal-contaminated groundwater, the suitability of a selected technology for such a purpose depends on the initial metal concentration, the residual metal concentration required, the removal performance on heavy metal compared to other technologies, and the overall treatment cost.