Treatment of arsenic containing drinking waters by electrochemical oxidation and reverse osmosis

摘要

Removal of most distributed inorganic arsenic forms, As(lll) and As(V), from drinking water was experimentally studied by using two methods - electrochemical oxidation and membrane separation. Transformation of As(III) into As(V) was performed by electrochemical oxidation. The effect of concentration parameters such as initial arsenic concentration (500 μg/L- 5000 μg/L), conductivity 700 μS/cm - 2000 μS/cm), and pH-value (5 - 10) on the transformation of the trivalent arsenic into pentavalent was investigated. Reverse osmosis by the new Dow Filmtec membrane BW30XFR was applied to separate the pentavalent arsenic from water. The hydrodynamic conditions (flow rate and pressure) were found at which arsenic concentration in the treated water lower than the limit value of 10 μg/L can be reached. The results showed that both methods can be successfully combined.