Sediment washing by EDTA and its reclamation by sodium polyamidoamine-multi dithiocarbamate
Sediment washing by EDTA and its reclamation by sodium polyamidoamine-multi dithiocarbamate
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EDTA 沉积物洗涤及聚酰胺胺-多二硫代氨基甲酸钠回收
DOI：
10.1016/j.chemosphere.2016.09.152
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发表时间：
2017-02-01
期刊：
影响因子：
8.8
通讯作者：
Jin, Luyao
中科院分区：
文献类型：
--
作者：
Deng, Tianlin;Zhang, Bingru;Jin, Luyao
聚氨基胺-多二硫代氨基甲酸钠（PAMAM-DTC）是一种重金属捕集剂，含有二硫代氨基甲酸酯功能基，对重金属有较强的螯合作用。本文将其应用于EDTA粗粉中重金属离子的沉淀和泥沙洗涤过程中EDTA的回收。研究了新鲜EDTA的萃取性能随EDTA浓度、液/渣（L/S）、pH和萃取时间的变化。然后用PAMAM-DTC、Na 2S和DDTC处理EDTA废水，比较它们对金属-EDTA络合物的捕集效果。四个二价重金属（铅，镉，铜，锌）进行了调查。PAMAM-DTC表现出更好的性能。PAMAM-DTC在350 mg·L-1的用量下几乎可以完全沉淀Pb、Cd和Cu，而Zn只能部分沉淀，这可能是由于Zn不能与其它3种金属离子竞争螯合作用的结果。回收的EDTA在三个循环的沉积物洗涤中重复使用，并且在每个循环中提取的重金属的量仅略有下降。(C)2016由Elsevier Ltd.出版
Sodium polyamidoamine-multi dithiocarbamate (PAMAM-DTC) is a kind of heavy metals capturing agent, containing functional groups of dithiocarbamate that could strongly chelate heavy metals. In this paper, it was applied to precipitate heavy metal ions from meal-EDTA and reclaim EDTA during sediment washing process. The extracting performance of fresh EDTA was studied as a function of EDTA concentration, liquid/sediment (L/S), pH, and extraction time. Then the EDTA effluents were treated with PAMAM-DTC, Na2S and sodium diethyldithiocarbamate (DDTC) to compare their effectiveness on capturing metals from metal-EDTA complexes. Four divalent heavy metals were investigated (Pb, Cd, Cu, Zn). PAMAM-DTC shows much better performance. Pb, Cd and Cu could almost be precipitated completely by PAMAM-DTC under the dosage of 350 mg L-1, while Zn could be only partly precipitated which may due to its failure in competition with the other three metal ions on chelation with PAMAM-DTC. The reclaimed EDTA was reused in three cycles of sediment washing, and the amount of heavy metals extracted just slightly decreased in each cycle. (C) 2016 Published by Elsevier Ltd.