[Factors affecting arsenic removal with copolymer coagulant and their mechanism]

The removal of arsenic from drinking water with copolymer coagulant was investigated. The effect of the component, additive substance of the coagulant and filtration were tested by employing a orthogonal analysis. The results showed that the arsenic removal with ferric sulfate was better than that with ferric-aluminum copolymer and polysilicon metal salt. Adding active carbon powder or kaoline could not enhance the efficacy of arsenic removal. However, the removal rate was improved by filtration after using coagulates, and sand filtration was feasible. The efficacy of arsenic removal could be affected by the column height filled with sand and the diameter of sand. After arsenic adsorption model fitted, the Lang-muire isotherm was matched. The main mechanism of arsenic removal by coagulation should be adsorption.