Removal of nitrate nitrogen from water by phosphotungstate-supported TiO2 photocatalytic method.

ABSTRACT

Nitrate nitrogen in water, especially in groundwater, is a major problem in the current drinking water environment. In this study, copper- and nickel-modified phosphotungstate catalysts supported on TiO2 were prepared by the sol-gel solvothermal method, and photocatalytic reduction by phosphotungstate was used to remove nitrate nitrogen in water under ultraviolet irradiation. The maximum removal rate was 59.60% with 0.8 g/L Cu-H3PW12O40/TiO2, 90 mg/L nitrate nitrogen, and 60 min reaction time. For Ni-H3PW12O40/TiO2, the maximum removal rate of nitrate nitrogen was 54.58%, achieved with a catalyst concentration of 0.8 g/L, nitrate nitrogen concentration of 120 mg/L, and reaction time of 30 min. Both catalysts could remove nitrate nitrogen from water under the condition of photocatalysis.