膨润土和改性膨润土对电镀污泥中重金属的稳定化处理

发布时间：2018-04-22 22:38

本文选题：环境学 + 改性膨润土　；参考：《安全与环境学报》2017年03期

【摘要】：采集某电镀厂污泥,以膨润土和改性膨润土为稳定剂,采用TCLP毒性浸出试验分析膨润土和改性膨润土对污泥中重金属Cr、Cd、Zn和Pb的稳定化效果。未加入稳定化剂前,电镀污泥中重金属Cr、Cd、Zn和Pb的浸出毒性分别为154 mg/L、13.5 mg/L、658 mg/L和76 mg/L。稳定化试验结果表明,在膨润土和改性膨润土的投加量与干污泥的质量比分别为1∶5和3∶10,振荡时间为12 h时,浸出液中重金属质量浓度最低,稳定化效果最好。形态分析结果表明,加入膨润土和改性膨润土稳定后重金属以有机结合态和残渣态为主,与未稳定前相比污泥中重金属不稳定态的含量变少。扫描电镜和红外分析结果表明,膨润土和改性膨润土可能通过吸附和离子交换来稳定污泥中的重金属。研究表明,改性膨润土对电镀污泥中高含量重金属的稳定化效果要优于未改性膨润土的稳定化效果。
[Abstract]:Using bentonite and modified bentonite as stabilizers, the effects of bentonite and modified bentonite on the stabilization of heavy metals Cr-CdPn-Zn and Pb in sludge were analyzed by TCLP toxic leaching test. Before the addition of stabilizer, the leaching toxicity of heavy metal Cr ~ (2 +) CD ~ (2 +) Zn and Pb in electroplating sludge was 154mg / L ~ (13.5) mg / L ~ (-1) mg/L and 76 mg / L ~ (-1), respectively. The results of stabilization test show that when the ratio of bentonite and modified bentonite to dry sludge is 1:5 and 3: 10, and the oscillation time is 12 h, the concentration of heavy metals in leaching solution is the lowest and the stabilization effect is the best. The results of speciation analysis showed that after the addition of bentonite and modified bentonite, the main heavy metals were organic bound state and residual state, and the contents of unstable heavy metals in sludge decreased compared with those before stabilization. The results of SEM and IR showed that bentonite and modified bentonite may stabilize the heavy metals in sludge by adsorption and ion exchange. The results showed that the stabilization effect of modified bentonite on high content heavy metal in electroplating sludge was better than that of unmodified bentonite.
【作者单位】：辽宁工程技术大学环境科学与工程学院;
【基金】：国家自然科学基金项目(41403100)
【分类号】：X781.1

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