MAP结晶法回收和去除尿液中的磷  

Phosphorus Removal and Recovery from Human Urine with MAP Crystallization

作　　者：赵庆良[1] 刘志刚[1] 李巍[1] 邱微[1] 王建芳[1] 

机构地区：[1]哈尔滨工业大学市政环境工程学院城市水资源与环境国家重点实验室,哈尔滨150090

出　　处：《环境科学》2007年第10期2223-2229,共7页Environmental Science

基　　金：教育部'长江学者与创新团队发展计划'项目;黑龙江省杰出青年科学基金项目(JC04-11)

摘　　要：以分解后的尿液为研究对象,采用MgCl2.6H2O溶液作为MAP结晶剂,对MAP结晶同步回收尿液中的磷和部分氮的影响因素Mg/PO43--P摩尔比、反应pH、反应时间、沉淀时间和搅拌速度等进行小试试验.结果表明,Mg/PO43--P摩尔比是重要的运行参数,当其摩尔比超过1.3∶1时,磷的回收率超过95%,上清液剩余PO43--P浓度小于10 mg/L,而提高反应pH不能明显增加磷的回收率.该工艺的最佳运行条件为反应时间20 min,沉淀时间2.0 h,搅拌速度120 r/min,不需要pH调节控制.选择Mg/PO43--P摩尔比分别为1∶11、.3∶1和1.5∶1,对在最佳条件下反应获得的3种产物采用SEM、XRD和ICP分析表明,3种产物都为比较纯净的MAP产品,其主要元素P、N、Mg的含量接近于MAP的理论含量(P=12.62%,N=5.71%,Mg=9.91%),分别为13.54%,5.34%,9.01%(Mg/PO43--P=1∶1)、13.78%,5.23%,9.36%(Mg/PO43--P=1.3∶1)和13.34%,5.12%,9.15%(Mg/PO43--P=1.5∶1),具有较高的回收利用价值.To realize the simultaneous removal and recovery of phosphate and partial nitrogen from stale human urine, a series of lab-scale jar tests, adopting MgCl2·6H2O as precipitant, were conducted to study the influence of the molar ratio of Mg/PO^3-4-P, pH, mixing speed, reaction time and precipitation time on MAP precipitation. The experiment results showed that the molar ratio of Mg/PO^3-4-P was found to be a very important operating parameter to affect phosphorus recovery efficiency. When the molar ratio of Mg/PO^3-4-P was above 1.3：1, the phosphorus recovery efficiency was above 95% and the residual phosphorous was less than 10 mg/L in the solution. Increasing pH with 10 mol/L NaOH solution could not increase the recovery phosphorus efficiency obviously. Without pH control, the optimal parameters of reaction time, precipitation time and mixing speed could be set at 20 min, 2.0 h and 120 r/min, respectively. To reveal the chemical characteristics of MAP products from human urine, three MAP product samples, with no pH adjustment and under the above optimal operation condition, were obtained at different Mg/PO^3-4-P molar ratios of 1 ： 1, 1.3 ： 1 and 1.5 ： 1, respectively, and analyzed with SEM, XRD and ICP instrumentation. These precipitates were identified as nearly pure struvite （ 12.62% of P, 5.71 % of N and 9.91% of Mg） with the presence of trace calcium, potassium and sodium. The contents of phosphorus, nitrogen and magnesium in the precipitates were 13.54%, 5.34% and 9.01% （Mg/ PO^3-4-P =1：1）, 13.78%, 5.23% and 9.36% （Mg/PO^3-4-P =1.3：1）, as well as 13.34%, 5.12% and 9.15% （Mg/PO^3-4-P =1.5： 1 ）, respectively.

关 键 词：尿液 磷 MAP 结晶 

分 类 号：X703.1[环境科学与工程—环境工程]