3. Bioprocesses for arsenic water treatment

3.1 Description of bioprocesses

Bioprocesses for the treatment of arsenic-contaminated water are currently under development, and are therefore not yet used on an industrial scale. At present, the main methods for removing As from water are filtration, coagulation, ion exchange and reverse osmosis. They generally require an initial stage of oxidation of As(III) to As(V) (when As(III) is present) by the addition of strong oxidants (potassium permanganate, hydrogen peroxide or ozone).

Biological oxidation processes could replace the chemical techniques used for As(III) oxidation.

This section presents processes for the biological oxidation of As(III) to As(V), as well as bioprocesses for the reduction of As(V) to As(III) and the precipitation...