优化电化学MAP法高效去除垃圾渗滤液中的氨氮

Optimized Electrochemical Magnesium Ammonium Phosphate Method for Efficient Ammonia Nitrogen Removal from Landfill Leachate

针对垃圾填埋场渗滤液中的高浓度氨氮,研究了基于电化学磷酸铵镁(MAP)法提高氨氮去除率与产物纯度的优化措施。结果表明,电化学MAP反应体系的氨氮去除率随初始pH的升高而降低;电化学MAP法可以在低pH条件下生成MAP沉淀,其中当pH在6.5~8.5之间时MAP生成速率最大且纯度高,这与传统MAP法的最佳pH为8~10有较大区别。采用分批投加KH2PO4可以提高整个体系中MAP的平均生成速率。当处理实际填埋场垃圾渗滤液时,电化学MAP法相比传统MAP法具有更高的氨氮去除率、较低的磷残余浓度以及更高的MAP纯度。

The optimized measures for improving ammonia nitrogen removal efficiency and product purity based on electrochemical magnesium ammonium phosphate(MAP) method were investigated to remove high ammonia nitrogen from landfill leachate. The removal efficiency of ammonia nitrogen in the electrochemical MAP reaction system decreased with the increase of initial pH. The electrochemical MAP method could generate MAP precipitate at low pH, and the MAP precipitate had the highest generation rate and high purity when the pH was between 6.5 and 8.5. The results was quite different from traditional MAP method at the optimal pH in the range of 8-10. The batch addition of KH2PO4improved the average MAP generation rate in the whole system. When treating real landfill leachate, the electrochemical MAP method had higher ammonia nitrogen removal efficiency, lower phosphorus residual concentration and higher MAP purity than the traditional MAP method.