Abstract

Orthogonal experimental plan was used to explorethe effect of aeration rate, electrolysis time, and current densityon the total phosphorus (TP) removal of sewage frompurification tank (Johkasou). The results showed that theremoval efficiencies of total phosphorus in ananode-cathode-anode electrolytic cell increased by from 3.4% to22.6% than that of an anode-cathode electrolytic cell. For theanode-cathode-anode electrolytic cell, the TP concentration ofeffluent could reach below 1mg/L (discharge standard foreffluent) with a TP removal rate above 95.9% under thecondition of electrolysis time of 60 mins or current density of 4mA·cm-2. Whereas the anode-cathode electrolytic cell mustrequire a combination with any two of the above threeexperimental factors at high levels to achieve the dischargestandard, and the TP removal rates were more than 92.6%.Aeration improved the phosphorus removal rate in theelectrolysis apparatus. Fourier transform infrared spectroscopy(FTIR) analysis showed that the precipitate ofelectro-coagulation was a mixture of hydroxyl iron phosphateand iron phosphate. The phosphorus of the sewage in theJohkasou could be effectively removed through sludgedischarge.