Methods for selenium removal from contaminated waters: a review

Worldwide contamination of waters by metals, metalloids, and organometallic pollutants is a major health issue. In particular, the occurrence of the selenium metalloid at rather high concentrations in the environment, especially in the water compartment, is of increasing concern, notably in developing countries. Selenium is difficult to remove from groundwater and industrial effluents because selenium is often present in complex polycontaminated mixtures, thus inducing competition issues with other anions. Moreover, the efficiency of remediation methods depends on selenium speciation and water parameters, e.g. pH and concentration of competing anions. Here, we review methods for selenium removal from water, wastewater, and industrial effluents. Technologies are based on zero-valent iron, iron-oxy-hydroxides, supported materials, nanofiltration, reverse osmosis, chitosan-enhanced ultrafiltration, electrodialysis, and activated granular sludge.