4. Conclusion and outlook

Autotrophic bacteria capable of synthesizing arsenite oxidase can considerably accelerate the rate of arsenic oxidation under low-oxygen conditions. Biological processes for the treatment of drinking water and mining effluent containing arsenite concentrations in the order of tens of μg.L ^–1 to tens of mg.L ^–1 , therefore appear to be promising technologies on a laboratory and pre-pilot scale. However, these processes currently need to be tested on an industrial scale in order to measure their robustness in the face of industrial constraints (flow rate, variation in arsenic load, presence of inhibiting elements and other micro-organisms, etc.). We also need to assess the technical and economic feasibility of these oxidation processes.

Finally, the bioreduction of As(V), coupled...