Abstract:

Na₂ HPO₄·12H₂O and MgCl ₂·6H ₂O react with highly concentrated ammonia-nitrogen from coke plant wastewater,forming magnesium ammonium phosphate(MAP).The effect of pH value on the ammonia-nitrogen removal result isexpolored emphatically.The experimental resultsshow that when the ratio of n(Mg²⁺)∶ n(NH₄⁺)∶ n(PO₄^3-)iscontrolled at1.3 ∶ 1 ∶ 0.9,the optimal pH isabout8.5to10.The NH 3-N in the original wastewater can be decreased from2380mg /L to lower than100mg /L.The formed MAP crystal hashigh purity.It doesnot adsorb the poisonousand harmful substancesin the wastewater.Furthermore,itssedimentation capability isgood.

Key words: magnesium ammonium phosphate, coke plant wastewater, ammonia-nitrogen, pH value

摘要：

采用化学药剂Na₂HPO₄·12H₂O和MgCl₂·6H₂O与焦化废水中的高浓度氨氮反应生成磷酸铵镁(MAP)，着重探讨了pH值对氨氮去除效果的影响。实验结果表明，在Mg²⁺，HN₄⁺，PO₄^3-物质的量比为1.3∶1∶0.9，得到最佳pH为8.5～10，原废水中的NH₃^-N可由2380mg/L降到100mg/L以下，生成的MAP晶体纯度较高，对废水中的有毒、有害物质无吸附，并具有良好的沉降性能。

关键词: 磷酸铵镁, 焦化废水, 氨氮, pH值

CLC Number: 

• X703.1