Removal of Ammonia Nitrogen from Coking Wastewater by Struvite Precipitation

摘要

This study investigated a wastewater treatment technique based on natural minerals.Ammonia nitrogen of coking wastewater was removed by chemical precipitation method using magnesia as a low-cost source of magnesium.In the optimum condition,86.6％ of initial N-NH4+ was removed with a S/L rate of 22g/L and reaction time of 24h.Almost all of phosphate was removed,the residual concentrations of N-NH4+,P-PO43-and Mn2+ were 297mg/L,0.4mg/L and 11mg/L respectively,which is necessary for COD removal by following biological treatment process.Struvite recovered may be used as a potential slow-release fertilizer.