【作者】 刘辉；

【导师】 刘月娥；

【作者基本信息】 新疆大学 ， 化学工程与技术， 2012， 硕士

【摘要】 本文以2010年取自乌鲁木齐市水务（集团）有限公司污水处理公司夏季和冬季污泥为研究对象，对污泥中主要重金属Cu、Zn、Pb、Cr进行了去除及稳定化研究，探讨了去除剂及稳定化剂的类型及去除工艺。结果表明：（1）通过对污泥的基本性质进行分析，该污泥的有机质含量较高，可用来作为土壤改良剂。（2）通过对污泥中重金属总量及存在形态分析，得出重金属Cu、Zn、Pb、Cr是实验污泥主要的重金属污染物，Cu的最高含量为700mg/kg，主要分布在不稳定态；Zn、Pb的最高含量分别为1290mg/kg、400mg/kg，主要分布在残渣态中； Cr的含量不高，但主要分布在不稳定态，被植物吸收利用的可能性很大，仍有很大的危害。Cd含量不高，且分布在稳定态中。污泥中Cu、Zn、Pb的含量超出了我国《农用污泥中污染物控制标准》中规定的限制，其他重金属的含量都低于农用标准的限制。（3）采用不同的化学去除剂硫酸铁、磷酸、EDTA、柠檬酸、SDS对污泥中铜、锌、铅、铬进行了去除研究。结果硫酸铁、磷酸的去除效果较好。各种去除剂对污泥中铜、铅去除能力的顺序是：硫酸铁>磷酸>EDTA>柠檬酸>SDS；对锌去除能力的顺序是：硫酸铁>磷酸>柠檬酸>EDTA>SDS；对铬去除能力的顺序是：磷酸>硫酸铁>柠檬酸>EDTA>SDS。Fe³⁺处理实验污泥的最佳工艺条件：6g/L的硫酸铁溶液，固液比为1∶50，反应温度45℃，反应时间3d。最佳工艺条件下Fe³⁺对铜、锌、铅、铬的去除率分别可达到76.22%、96.28%、30.65%、52.57%。H₃PO₄处理实验污泥的最佳工艺条件：10%的磷酸溶液，固液比为1∶12.5，5%H₂O₂投加量的液固比为（1∶1.2），反应温度40℃，反应时间24h。最佳工艺条件下H₃PO₄对铜、锌、铅、铬的去除率分别为46.34%、64.86%、21.52%、72.67%。（4）采用膨润土和腐殖酸做为稳定化剂对污泥中铜、锌、铅、铬进行了稳定化研究。新疆夏子街膨润土处理实验污泥的最佳工艺条件为：室温，振荡时间12h，浸提液pH值为6左右，投加量与干污泥质量比（g/g）为1:12.5。最佳工艺条件下膨润土对铜、锌、铅、铬的稳定率为92.67%、98.08%、100%、97.6%。经过膨润土稳定化后，污泥中的重金属主要分布在残渣态，少量分布在硫化物及有机结合态，而分布在不稳定态的含量较少。腐殖酸稳定化处理实验污泥的最佳工艺条件为：室温，振荡时间8h，浸提液pH值为6左右，投加量与干污泥质量比（g/g）为1:5。最佳工艺条件下，腐殖酸对重金属铜、锌、铬的稳定率分别为89.4%、96.36%、81.71%。经过腐殖酸稳定化后，污泥中的重金属主要分布在残渣态，少量分布在硫化物及有机结合态，不稳定态的含量较少。（5）通过上述研究及经济性分析得出：用膨润土对实验污泥中重金属进行处理是最佳方案，重金属的稳定化过程可与污泥的堆肥工艺结合起来。在最佳工艺条件下，用膨润土处理1t干污泥的费用约为60元左右。更多还原

【Abstract】 The main research objective in this paper is the sludge generated by UrumqiWater （Group） Co.Ltd in the summer and winter of2010. The approach to theremoval and stabilization of main heavy metals Cu、Zn、Pb、Cr leads to a discussionof the types and process of the removal agent and stabilizing agent. The resultsindicates that:（1） The sludge consists a high percentage of organic matter content which can beused as a soil improver according to the analysis of the its basic properties.（2） According to heavy metals content and chemical speciation analysis in sludge,we can find that the Cu, Zn, Pb, Cr are the main heavy metal pollutants whilethe highest content of Cu is700mg/kg, which is mainly distributed in the unstablestate; correspondingly, the highest content of Zn and Pb are1290mg/kg and400mg/kgrespectively, which is mainly distributed in the residual fraction. The content ofCr is not high, but mainly located in unstable state, so it has a high possibility to beabsorbed and utilized by plants that is greatly harmful. The content of Cd thatdistributed in the unstable state is low. The content of Cu, Zn, Pb in sludge exceed ourcontrol standards of pollutants in agricultural utilization of City sewage sludge, whilecontent of the other heavy metals are lower than the agricultural standard limit.（3） Different chemical removal agent, such as, ferric sulfate, phosphate, EDTA,citric acid, SDS, are chosen for the study on the removal of Cu, Zn, Pb, Cr in sludge.The results show that ferric sulfate and phosphate have the best effects.The order of extraction capacity of copper, Lead is: Ferric sulfate> phosphate>EDTA> citric acid>SDS; the order of the extraction capacity of Zinc is: ferricsulfate> phosphate> citric acid> EDTA> SDS; The order of the extraction capacityof Chromium is: phosphate> Ferric sulfate> citric acid> EDTA>SDS.The optimum conditions of Fe³⁺handling experimental sludge: concentration is6g/L, solid-liquid ratio is1:50, reaction temperature is45℃, reaction time is3d. Theremoval rate of copper, zinc, lead, chromium is76.22%、96.28%、30.65%、52.57%on the optimum conditions.The optimum conditions of phosphate handling experimental sludge: theconcentration is10%, solid-liquid ratio is1:12.5, liquid–solid ratio is1:1.2, reactiontemperature is40℃, and reaction time is24h. The removal rate of copper, zinc, lead,chromium is46.34%,64.86%,21.52%,72.67%on the optimum conditions.（4） The study on stabilization of Cu, Zn, Pb, Cr is conducted by using bentoniteand humic acid.The optimum conditions of Xinjiang summer street bentonite handlingexperimental sludge: Room temperature, duration of oscillation is12h, leaching liquorpH value is around6, dosage and dry sludge mass ratio （g/g）is1:12.5. the stable rateof copper、zinc、lead、chromium is92.67%、98.08%、100%、97.6%on the optimumconditions. After bentonite stabilizing, heavy metals in the sludge are mainlydistributed in the residual, a small amount of the distribution in sulfides and organicform, while the distribution in unstable state less content.The optimum conditions of humic acid handling experimental sludge: Roomtemperature, duration of oscillation is8h, leaching liquor pH value is around6,dosage and dry sludge mass ratio （g/g）is1:5. The stable rate of copper、zinc、chromium is89.4%、96.36%、89.4%on the optimum conditions. After humic acidstabilizing, heavy metals in the sludge are mainly distributed in the residual, a smallamount of the distribution in sulfides and organic form, while the distribution inunstable state less content.（5） Based on above research and economic analysis, it demonstrates that the bestsolution for processing heavy metals in experimental sludge is to use bentonite.Heavy metal stabilization process can be combined with sludge compost technology.Under the optimum conditions, the costs of processing1tons of sludge by bentonite isabout60RMB.更多还原