鸟粪石结晶成粒技术回收污泥液中磷的中试研究

摘要

In order to investigate the application conditions and product quality of struvite (MAP) pellet crystallization technology in actual engineering, a pilot-scale MAP reactor was used to recover phosphorus from sludge liquor derived from a sewage treatment plant in Wuxi. The optimal conditions for the struvite pellet formation were confirmed as follows: pH = 9.0, N:P:Mg molar ratio =4:1: 1.3, reaction time=4d. Under the above optimal conditions, the recovery efficiency of PO43--P reached 85%, the average size of the harvested struvite particles was 0.74mm, and the struvite purity reached 98.23%. The harvested struvite particles have rhombic structure and with high purity. Economic analysis indicates that the total pharmaceutical cost of struvite pellet crystallization for phosphorus recovery is 0.38yuan/t sludge liquor.%为了探究鸟粪石(MAP)结晶成粒技术在实际工程中的应用条件及价值,利用鸟粪石中试反应器处理无锡某污水处理厂污泥脱水液,确定了鸟粪石结晶成粒技术回收磷的最佳工况:pH=9.0,摩尔比N:P:Mg=4:1:1.3,反应周期为4d.最佳条件下脱水液磷回收率达85%,收获的鸟粪石平均粒径为0.74mm,纯度可达98.23%.收获的MAP颗粒为规则斜方晶结构,品质较好,颗粒纯度高杂质少.经济分析表明,鸟粪石结晶成粒技术回收每吨污泥液中磷的药剂成本为0.38元.