Application of Chemical Precipitation in Treating Ammonia Nitrogen from Excess Sludge Liquor

摘要

Removal effect of NH_3-N by chemical precipitation process was studied in treating excess sludge liquor (the NH_3-N concentration 600~1000mg/L) produced from a municipal wastewater treatment plant. MgSO_4 and Na_2HPO_4 were used as the precipitants to investigate the influences of initial pH, reaction time and the precipitants dosage on the NH_3-N removal effect as well as the concentration of residual TP. Results showed that with the initial pH of 11.0, reaction time of 10min, and the additional ratio of precipitants being Mg:N:P＝1.0:1.0:1.0, over 90% NH_3-N removal efficiency was achieved which would significantly facilitate the subsequent biological treatment process.