高温改性凹凸棒土钝化城市污泥中重金属研究  

Study on the Passivation of Heavy Metals in Municipal Sludge by Attapulgite Modified at High Temperature

作　　者：殷萌[1] 刘红[1] 刘梦佳[2] 汪茜 张惠灵[1] YIN Meng LIU Hong LIU Mengjia WANG Qian ZHANG Huiling(School of Resource and Environmental Engineering, Wuhan University of Science and Technology, Wuhan 430081, China School of Resource and Environmental Science, Wuhan University, Wuhan 430079, China Hubei Academy of Environmental Sciences, Wuhan 430072, China)

机构地区：[1]武汉科技大学资源与环境工程学院,湖北武汉430081 [2]武汉大学资源与环境科学学院,湖北武汉430079 [3]湖北省环境科学研究院,湖北武汉430072

出　　处：《环境科学与技术》2017年第6期93-97,共5页Environmental Science & Technology

基　　金：国家自然科学基金项目(50904047);湖北省环保厅项目(2015HB05)

摘　　要：针对一些城市污泥中重金属镉、锌、砷超过污泥排放A级标准的问题,以高温改性凹凸棒土为钝化材料,考察了煅烧温度、掺杂比对凹凸棒土钝化重金属效果的影响,探讨了钝化机理。结果表明:在煅烧温度为700℃、掺杂比为15%时,凹凸棒土对污泥中重金属的钝化效果最佳,对镉、锌、砷的钝化率最高分别可达99.6%、92.7%和87.6%;凹凸棒土经700℃煅烧后,晶体结构发生断键,同时分解生成CaO和MgO等碱性氧化物,使污泥碱性升高,其中的镉、锌因赋存形态被改变而得到钝化。砷的钝化可能是凹凸棒土上的Al—OH键断裂后,Al与亚砷酸根形成络合物而实现的。For the problem that the content of heavy metal cadmium, zinc and arsenic in some municipal sludge exceeded the discharge standard of Grade A, the effects of calcination temperature and doping ratio of attapulgite on the passivation ef- ficiency of heavy metals were investigated by using attapulgite modified at high temperature as passive material. The passivation mechanism of cadmium, zinc and arsenic was explored. The results showed that the optimal passivation effect was achieved by attapulgite calcined at 700 ~C and doped as 15%, and the highest passivation rate of cadmium, zinc and arsenic reached 99.6%, 92.7% and 87.6%, respectively. After being calcined at 700℃, the chemical bonds in the crystal lattice of attapulgite were broken, and attapulgite decomposed to some alkaline oxide like CaO and MgO, which increased the alkalinity of sludge and thus resulted in the change of occurrence form of cadmium and zinc. The passivation of arsenic was realized owing to the formation of complex with Al and arsenate after the Al-OH bond in attapulgite was broken.

关 键 词：凹凸棒土 高温改性 城市污泥 重金属 钝化 

分 类 号：X703[环境科学与工程—环境工程]