基于双层双阳极装置的电动去除和回收城市污泥中重金属的研究

发布时间：2018-02-16 02:10

本文关键词： 城市污泥重金属电动修复表征　出处：《浙江大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着中国经济的飞速发展和城镇化进程的不断加快,我国城市污泥的产量也迅猛增加。城市污水中部分工业废水的汇入,导致城市污泥中积累了一定量的重金属,如果不对污泥中重金属进行去除或回收,不仅将严重影响着污泥农用、堆肥、焚烧、填埋等后续处置方法的应用,还会造成金属资源的极大浪费和经济损失。本文着眼于未来工业应用,采用自行研发设计的双层双阳极装置,利用乙二胺作为整合剂来强化去除和回收城市污泥中的重金属,并对阴极沉淀产物进行表征,以期探索工业上可行的城市污泥重金属的去除和回收技术。(1)在综合分析研究现状、了解已有电解装置局限的基础上,自行设计制作了双层双阳极电动试验装置,新装置能显著提高污泥中重金属的去除效率,且单次处理量大。预试验表明,新装置的污泥处理量由原来的2.5L提升到了 9L;Cu的去除率由原来的67.64%上升到了 76.02%,Pb的去除率由原来的57.79%上升到了 60.23%,Zn的去除率由原来的87.51%上升到了 89.13%。(2)电动去除和回收城市污泥中重金属的试验表明,综合考虑去除效果和经济效益,本试验确定的最佳电流密度为1.2nmA/cm~2。三组试验中,Zn、Cu的最终去除率随电流密度的增加而增大,而Pb、Cr的去除率却随着电流密度的增加先减小后增加。(3)乙二胺协同电动去除和回收城市污泥中重金属的试验表明:1)乙二胺的添加可以强化污泥中各重金属的捕集和去除效果。2)乙二胺与污泥的体积比(V乙二胺/V污泥)为0.06时为最佳电流密度(1.2 mA/cm~2)下的最佳添加比。3)在电解过程中Cu、Pb、Cr三种含量较小的重金属之间并不存在相互竞争关系,或者不存在明显的竞争关系,三种金属与Zn存在一定的竞争关系。(4)阴极沉淀产物的表征结果显示,混合物中主要含有Zn、Fe、Cu、Cr、Na、Ca、K、Mg、Pb等9种金属元素和Si、Cl、S等3种非金属元素,且含量大小依次为ZnFeCuCrNaCaKSiMgPbClS。烘干后的阴极沉淀中最可能含有 ZnO、ZnS、CuS、CuO、PbS、PbO_2和KxCrO_2 等物质,其中 Zn 可能主要以ZnO和ZnS的形式存在,Cu可能主要以CuO和CuS的形式存在,Cr可能主要以KxCrO_2的形式存在,而Pb可能主要以PbS和PbO_2的形式存在。
[Abstract]:With the rapid development and urbanization China economy is accelerating, China's city sludge production has increased rapidly. Some industrial wastewater into the city sewage in the city, leading to heavy metals in sludge accumulated a certain amount of heavy metals in the sludge, if not for the removal or recovery, not only will affect agricultural sludge, compost. The application of incineration, landfill and other disposal methods, the metal will cause great waste of resources and economic losses. This paper focuses on the future of industrial application, using self-developed double anode device design, using ethylenediamine as chelating agent to enhance the removal and recovery of heavy metals in the sludge of city, and the products were characterized by cathode precipitation. Explore the removal of feasible city sludge heavy metal industry and recycling technology. (1) in the comprehensive analysis of the status quo, understand the existing electrolytic device limited basis On the designed double anode electric test device, the new device can significantly improve the removal efficiency of heavy metals in sludge, and a single large quantity. Pre test shows that the sludge treatment equipment from 2.5L to 9L; the removal rate of Cu increased from 67.64% to 76.02%. The removal rate of Pb increased from 57.79% to 60.23%, the removal rate of Zn increased from 87.51% to 89.13%. (2) shows that the test and recovery of heavy metals in sludge removal Electric City, considering the removal effect and economic benefits, the best current density was confirmed as the three group of 1.2nmA/cm~2. test, Zn the final Cu removal rate with the increase of current density increases, the removal rate of Cr and Pb, but with the increase of the current density decreased and then increased. (3) ethylenediamine synergy test and recovery of heavy metals in sludge removal Electric City show that: 1) The addition of the ethylenediamine heavy metal ions in the sludge collection and removal of.2 and the volume ratio of sludge) ethylenediamine (V ethylenediamine /V sludge) was 0.06 for the optimal current density (1.2 mA/cm~2) under the optimal add ratio.3) in the electrolysis process Cu, Pb, there is no competition between the heavy metal Cr three a content is small, or there is not a significant competitive relationship, there is competition between the three kinds of metal and Zn. (4) characterization of cathode precipitation product showed that the mixture contains Zn, Fe, Cu, Cr, Na, Ca, K, Mg, Pb and other 9 kinds of metal elements and Si and Cl, 3 kinds of metal elements such as S, and the size of the content in cathode ZnFeCuCrNaCaKSiMgPbClS. after drying the precipitate may contain ZnO, ZnS, CuS, CuO, PbS, PbO_2 and KxCrO_2 etc, in which Zn may mainly ZnO and ZnS exists in the form of Cu, CuO and CuS may be the main form of existence Cr. It can exist mainly in the form of KxCrO_2, and Pb may exist mainly in the form of PbS and PbO_2.

【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X703

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