Research on removing selenium from raw water by using Fe/Se co-precipitation system

The effect of selenium removal from raw water by using Fe/Se co-precipitation system is noticeable. Experiments showed that when the concentration of Se in raw water was 50 μg L⁻¹ and the dosage of FeCl₃ was between 5–80 mg L⁻¹,the system could reach selenium removal of between 83.84%–98.39% and the effluent selenium was between 8.08−0.81 μg L⁻¹. The effluent concentration of selenium met the Chinese drinking water quality standard for selenium content. Research on factors influencing the Fe/Se co-precipitation system, showed that the optimum dosage of FeCl₃ was 5 mg L⁻¹, the optimum mixing time was between 5–10 min, the optimum pH was 6.0–8.0, the optimum turbidity of raw water and the optimal temperature had a wide range of application.