Abstract: The wastewater containing about 2 g/L magnesium ions from MgO flue gas desulphurization slag has been used for removing nitrogen and phosphorus of wastewater. Influencing factors that have effects on the removal of nitrogen and phsphorus by using the wastewater are discussed. The results show that for the wastewater containing 578 mg/L of NH₃-N and 1352 mg/L of PO₄^3--P, the removing rates of NH⁴⁺-N and phosphate are 80% and 91.5%, respectively, under the following optimal conditions:n(Mg²⁺):n(NH⁴⁺):n(PO₄^3-)=2:1:1.6, pH=9.5, reaction time=10 min, stirring speed about 300 r/min. The MAP as prepared can be used as slow-release fertilizer. The results show that applying MgO flue gas desulphurization wastewater to the removal of nitrogen and phosphorus of wastewater can reach the goal of “treating waste with waste”. Therefore, this process has very good prospect.

Key words: magnesium-containing desulphurization wastewater, removal of nitrogen and phosphorus, magnesium ammonium phosphate

摘要： 将含有2 g/L镁离子的镁剂烟气脱硫废水用于废水脱氮除磷，探讨了影响废水脱氮除磷效率的因素。结果表明，对NH₃-N为578 mg/L、PO₄^3--P为1352 mg/L的废水，当 n（Mg²⁺）：n（NH⁴⁺）：n（PO₄^3-）=2：1：1.6，pH=9.5，反应时间为10 min，搅拌转速为300 r/min时，氨氮去除率可达到80%，磷酸盐去除率达到91.5%。脱氮除磷的产物磷酸铵镁（MAP）可以用做缓释肥等。将镁剂烟气脱硫废水用于废水脱氮除磷，可达到以废治废的目的，该技术具有良好的应用前景。

关键词: 镁剂脱硫废水, 脱氮除磷, 磷酸铵镁

CLC Number: 

• X703