(21a) Removal of Arsenic from Contaminated Water and Soil

Arsenic is widely recognized as a persistent and toxic contaminant that is harmful to humans. The most dangerous form of arsenic involves arsenate (As+5) and arsenite (As+3). Human activities involving arsenic include smelting, mining, discharge of wastewater and wastes, irrigation, and pesticide application. Elevated arsenic concentrations present global health concerns. This presentation will address common treatment techniques used to remove arsenic from waters and soils contaminated with arsenic compounds. Where possible, performance data will be provided related to the treatment technique.

The current standard for arsenic concentration in water is 10 micrograms/L. Common treatment techniques for removal of arsenic from water include chemical coagulation/flocculation (also considered as chemical precipitation processes), lime softening, biochar adsorption and other adsorbents, coagulation/filtration, filtration/reverse osmosis, oxidation/filtration, membrane processes (electrodialysis and reverse osmosis), and ion exchange.

Common treatment techniques for removal of arsenic from soil include chelant extraction, biological treatment using fungi, electronic and permeable reaction barriers, phosphoric acid combined with phosphate, surfactants coupled with phosphate, phytoremediation, and electrocoagulation.

The presentation will describe each of these arsenic treatment techniques and provide performance data when reported.