鸟粪石结晶法回收磷中Ca^(2+)对产物沉淀特性的影响  

IMPACT OF Ca^(2+) ON THE PRODUCT PRECIPITATION IN PHOSPHOROUS RECOVERY BY STRUVITE CRYSTALLIZATION

作　　者：李晋雅 张顺[1] 戴荣海[2] 汤曼琳 田晴[1] 

机构地区：[1]东华大学环境科学与工程学院,上海201610 [2]中船第九设计研究院工程有限公司,上海201620

出　　处：《环境工程》2014年第2期54-58,67,共6页Environmental Engineering

基　　金：留学回国人员科研启动基金(11W11329);上海市自然科学基金(102R1401200);中央高校东华大学基本科研业务费专项资金(11D11308)

摘　　要：分析废水中Ca2+对鸟粪石结晶法回收产物沉淀的影响。观察不同Ca、Mg物质的量配比n(Ca)∶n(Mg),不同起始磷浓度条件下磷回收产物在Inhoff管中的沉淀过程,测定总磷及溶解性磷的去除效率;同时利用扫描电镜(SEM)观察产物微观尺寸及形态、利用X射线衍射仪(XRD)、元素分析法分析沉淀物组成,联系沉淀过程分析Ca2+对磷回收产物固液分离的过程及其效率的影响。随着Ca2+的增加,上清液中溶解性磷(DP)与总磷(TP)去除率之差由1%逐渐增大到10%以上;沉淀产物颗粒尺寸由25μm左右减小至5μm甚至更小,最终失去晶体形态;沉淀产物中鸟粪石含量逐渐降低、钙磷沉淀比例逐渐增多。随着Ca2+的增加,沉淀过程有明显的变化,上清液中颗粒磷逐渐增多,且产物中鸟粪石含量逐渐减小,总磷回收率下降;而在n(Ca)∶n(Mg)<0.3时,中、低浓度的含磷废水的回收产物仍然以鸟粪石为主。The effect of Ca2＋ on the product precipitation in phosphorous recovery by struvite crystallization in wastewater was studied in the paper. The precipitation processes occurring in Inhoff precipitation tube for the wastewater containing low to medium levels of phosphorous with different n（ Ca）： n（Mg） were investigated. At 30mins and 60mins from the start of precipitation, the removal rates of dissolved phosphorus and total phosphorus were analyzed. The micro crystalline sizes and morphology of the recovered products were observed by scanning electron microscopy （SEM）. The composition of the recovered P products was assayed by X-ray diffraetometer （XRD） and the method of element analysis. With the increase of Ca2＋ involvement, the difference of the removal rates between the dissolved phosphorus and total phosphorus increased gradually from 1% to 10% ; The granule sizes of the recovered products decreased from 25p, m to 5μm or even smaller, eventually the products contained no the crystal structure as evidenced by the gradual disappearing of the struvite characteristic peak in XRD detection; Elemental analysis also showed that Ca2 ＋ content increased gradually. With the increase of Ca2 ＋ , the precipitation process changed significantly, the granular phosphorus increased gradually in the supernatants and the struvite content in the product recovered decreased gradually; Struvite was still the predominant species in the recovered products when n（Ca） ： n（Mg） 〈 0. 3 in the recovery processes for wastewater containing low to medium levels of phosphorous.

关 键 词：磷回收 鸟粪石结晶法 CA2+ 沉淀过程 

分 类 号：X703[环境科学与工程—环境工程]