Abstract:

The return flow in the wastewater treatment plant contains highly concentrated ammonia nitrogen and phosphorus．When returning to the water treatment system，it has effect on the removal of ammonia nitrogen and phosphorus．Therefore．it is necessary to treat ammonia nitrogen and phosphorus separately． e return flow from a wastewater treatment plant iS tested and the conditions of recovering the ammonia nitrogen and phosphorus init by precipitation—flotation has been studied．Th e results show that the ammonia and phosphonis in the return flow can be precipitated with MgCl₂ and Na₂HPO₄ as precipitants． e best pH value is 10． e recovery rate of ammonia nitrogen in precipitation process reaches 89．09％.and the recovery rate of phosphorus reaches 98．79％. When AN』2 iS used as air-floating agent．the air．floating recovery rate reaches 94．91％.

Key words: return flow, precipitation-floatation, magnesium ammonia phosphate

摘要：

污水处理厂回流液中含有较高浓度的氨氮和磷,返回水处理系统时会影响对氨氮和磷的去除,因此有必要单独处理回流液中的氨氮和磷。作者对某污水处理厂污泥过滤产生的回流液进行了试验,研究了用沉淀气浮法回收其中氨氮和磷的条件。结果表明,采用沉淀浮选法可以回收其中的氨氮和磷。以磷酸氢二钠和氯化镁为沉淀剂,沉淀最佳pH为10,氨氮、磷的回收率分别达到89.09%、98.79%。以AN-2为气浮剂,沉淀产物磷酸铵镁的气浮回收率可达到94.91%。

关键词: 回流液, 沉淀气浮, 磷酸铵镁

CLC Number: 

• X703.1