垃圾焚烧飞灰去除水体中高浓度磷酸盐

Concentrated Phosphate Removal by Municipal Solid Waste Incineration Fly Ash

实验考察垃圾焚烧飞灰去除水中高浓度磷酸盐的主要影响因素,通过X射线衍射、透射电子显微镜检测、比表面与孔径测试初步探讨了飞灰除磷机理.结果表明,飞灰除磷速率很快,常温30.min磷去除率大于99.5%,受温度影响小,pH值适应性较强,除磷能力约6.0 mg/g.透射电镜照片从微观尺度上说明飞灰在除磷过程中未出现多孔结构,比表面积小于6.1.m2/g,吸附能力弱,吸附作用不是除磷的主要机制.化学沉淀是除磷主要机制,Ca2+是除磷过程的主要阳离子.X射线衍射测试结果表明飞灰晶相组成复杂,但其中的CaSO4很可能是Ca2+的主要来源.飞灰中部分重金属与磷酸盐发生沉淀反应,在除磷的同时稳定化了重金属.

The main influencing factors in phosphate removal by municipal solid waste incineration（MSWI） fly ash were investigated.The phosphate removal mechanisms of MSWI fly ash were studied through the tests of XRD,TEMs,urface area and pole size distribution.The results indicated that 99.5% of phosphate is removed within 30 min under room temperature,and that temperature and pH value have insignificant influence on the removal rate of phos-phate.The phosphate removal ability of MSWI fly ash is about 6.0 mg/g.TEM pictures showed that no porous materi-als are found during the reaction process,and that the surface area of MSWI fly ash is less than 6.1 m2/g,which proves that absorption is not the main mechanism of phosphate removal.Instead,Chemical precipitation is recognized as the main mechanism,and Ca2＋ is the main cation in the course of phosphate removal.XRD tests showed that the components of MSWI fly ash are complicated,yet CaSO4 is likely to be the main source of Ca2＋.During precipita-tion reaction among partial soluble heavy metals in fly ash and phosphate,phosphate is removed and heavy metals are stablized simultaneously.