Photoelectrochemical abatement of arsenic in water by hematite photoelectrodes

Arsenic is considered as one of the major issues among drinkable water pollutants because of its widespread distribution and its low acceptable limits. The most widely used removal technology involves arsenic adsorption on iron oxides, but this process is more effective for As(V). Since in groundwater arsenic is usually present as As(III), a preliminary oxidation treatment is often required to get high abatement yields. Moreover, despite it is a cheap and effective technology, adsorption generates a contaminated bed that must be disposed as toxic waste or regenerated by expensive techniques. Aiming at solving such problems, we are developing an alternative process involving a one-pot photoelectrochemical in situ oxidation and adsorption. Hematite nanostructured photoelectrodes showed promising performances by achieving almost complete abatement of arsenic from aqueous solutions under simulated solar light irradiation, in the view of economic and environmental sustainable application.