The removal of inorganic anions from municipal secondary effluent using magnetic ion exchange resin

摘要

The primary objective of this research was to evaluate the effectiveness of a magnetic ion exchange process (MIEX) in removing inorganic anions from municipal secondary effluent. Municipal secondary effluent drew from Gaobeidian wastewater treatment plant treating about 800,000 m3/day domestic wastewater. In the pilot experiment, MIEX resin removed 37.01% phosphorus, 31.62% nitrate, 36.06% ammonium and 64.34% sulphate from municipal secondary effluent. Phosphorus concentration in resin influent influenced reclaimed water treatment efficiency. Phosphorus removal rate was positively correlated with the concentration in influent. If phosphorus concentration in influent was >0.82mg/L, phosphorus removal of >52% was achieved. Nitrate and sulphate removal had same variation laws. 18.92% average removal rate of nitrate in middle period was lower than 35.06% and 39.25% average removal rates in earlier and latter periods respectively. The average removal rates of ammonium in three periods were 83.03%, 43.51% and 84.29% respectively. Removed ammonium of each sample was about 0.250mg/L, average removal rate was 36.06%. Lower ammonium concentration in influent could cause higher removal rate. Otherwise, magnetic ion exchange process could increase turbidity and could not disinfect, the resin effluent will be treated with coagulationsedimentation and ozonation for groundwater recharge research with reclaimed water.