我国城镇污水处理厂每年排放大量的剩余污泥，处理不当将给生态环境和人类健康带来风险。通过污泥碱解+鸟粪石结晶法回收剩余污泥中磷、氮等物质，将剩余污泥资源化的同时还可以有效避免二次污染。以徐州某污水处理厂剩余污泥为实验对象，通过实验室控制碱解pH、反应时间、镁盐投加量等考察了回收的最佳条件。结果表明，当pH为12.5，破解时间为120 min时，污泥破解效果最好；经综合分析，碱解+沉淀过程最佳条件为：碱解pH为12，镁磷摩尔比为1.4，鸟粪石结晶时间为10 min。

A large amount of excess sludge are discharged from urban sewage treatment plants every year, which will bring about risks to ecological environment and human health without suitable treatment. Phosphorus and nitrogen in the sludge are recovered through alkaline decomposition and struvite crystallization methods, thus the excess sludge becomes resource while secondary pollution is avoided effectively. Taking the excess sludge from a sewage treatment plant in Xuzhou as test object, the optimal recovery conditions are studied through controlling and changing pH in alkaline decomposition, reaction time, and dosage of magnesium salt. The results show that the optimal disintegration efficiency for sludge is achieved when pH is 12.5 and the reaction time is 120 min. In a sum, the optimal conditions for alkaline decomposition and struvite crystallization are as follows:pH is 12 in the process of alkaline decomposition, the molar ratio of Mg to P is 1.4 and the struvite crystallization spends 10 min.

周东来(1959-),男,学士,高级实验师,研究方向为环境科学,zdl9898@126.com。