【作者】 贾保军；

【导师】 周集体； 张爱丽；

【作者基本信息】 大连理工大学 ， 环境工程， 2006， 博士

【摘要】 近年来，由于电化学技术在废水治理方面的优势，该技术崭露出良好的应用前景，多相催化技术在环境废水的处理方面的应用研究也越来越深入。本文将电化学与多相催化有机结合起来，以复极固定床电解槽（BPBC）为反应器，用负载金属氧化物的多相催化剂取代传统反应器的绝缘填料，构建了多相催化电解耦合体系。分别以硝基苯和苯酚为电解底物，考察了不同催化剂填料存在情况下，有机物在多相催化电解耦合体系中的降解情况。主要得出如下结论： 采用BPBC分别处理硝基苯和苯酚废水，电解硝基苯的优化条件：电解电压40 V、支持电解质Na₂SO₄浓度为1000 mg·L^-1、pH值为10、水力停留时间45 min：硝基苯的去除率为61.4％；电解苯酚废水的优化条件：电解电压为25 V、支持电解质Na₂SO₄浓度为1000 mg L^-1、pH值为2.5；100 mg L^-1的苯酚电解45 min，去除率为42.6％；BPBC对硝基苯和苯酚的降解过程符合一级动力学模型。 多相催化电解耦合工艺处理硝基苯废水的优化工艺条件为：电解电压40 V、支持电解质Na₂SO₄浓度为500 mg·L^-1、pH值为10、水力停留时间45 min。经过对硝基苯降解效果的评价，筛选出了实验范围内的最佳催化剂为Fe₂O₃／γ-Al₂O₃。在用催化剂Fe₂O₃／γ-Al₂O₃为填料时，硝基苯的降解过程符合一级动力学模型；硝基苯和TOC的去除率分别为75.1％和39.8％。在引入多相催化剂后，硝基苯的处理效果有了显著的提高，硝基苯和TOC的去除率分别提高了13.7％和12.6％。硝基苯电解后，出水的可生化性有了显著的提高，BOD₅／COD_cr，由0.06升高到0.307。 用HPLC和GC-MS对硝基苯电解出水的产物进行分析，得到的产物有苯酚、苯胺、对氨基苯酚等物质，推测硝基苯在多相催化电解耦合工艺中的降解途径为：硝基苯可由电化学氧化直接分解，也可以由电解产生的次生氧化物间接氧化分解；除电化学氧化，也存在硝基苯电化学还原，生成苯胺、对氨基苯酚等物质，产物再进一步分解直至矿化；电解过程中硝基苯部分会矿化。 多相催化电解耦合工艺处理苯酚废水的优化工艺条件为：电解电压25 V、支持电解质Na₂SO₄浓度为1000 mg·L^-1、pH值为2.5、水力停留时间45 min。筛选出实验范围内处理苯酚的最优催化剂为Fe₂O₃／ZSM-5。在优化实验条件下，以催化剂Fe₂O₃／ZSM-5为多相催化电解耦合工艺反应器的绝缘填料，苯酚的降解过程符合一级动力学模型；多相催化电解耦合工艺处理苯酚的效果比传统的BPBC有了明显的提高，苯酚的去除率从42.6％提高到83.5％，COD的去除率从22.3％提高到43.4％，多相催化电解耦合工艺比传统的BPBC电解苯酚的COD去除效率增加了近一倍。更多还原

【Abstract】 In recent years, electrochemical technology has many advantages in removing pollutants from wastewater. Heterogeneous catalytic technology has been used in the treatment of environmental wastewater. In this study, with the combination of electrochemistry and heterogeneous catalysis in the bipolar packed bed cell, the electric nonconducting particle was replaced by catalyst and heterogeneous catalytic reactions occurred in an electrochemical reactor. And a novel electrochemical heterogeneous catalytic reactor was constituted by combination of electrochemistry and heterogeneous catalytic process. Nitrobenzene and phenol were selected as treatment objects by the new process. The degradation of the organic was investigated and primary conclusion was as followed.The traditional bipolar packed bed cell was used to treat nitrobenzene and phenol from wastewater. The optimal conditions of nitrobenzene electrolysis were determined as: applied potential of 40 V, Na₂SO₄ concentration of 1000 mg L^-1 and pH 10. Under optimal conditions nitrobenzene removal was 61.4%. And the optimal conditions of phenol electrolysis were determined as: applied potential of 25 V, Na₂SO₄ concentration of 1000 mg L^-1 and pH 2.5. Under optimal conditions phenol removal was 42.6%. Both the apparent kinetics on nitrobenzene and phenol removal can be expressed as the pseudo-first order reaction.Treatment of nitrobenzene wastewater by electrochemical heterogeneous catalytic process, the optimal conditions of nitrobenzene removal were as: applied potential of 40 V, Na₂SO₄ concentration of 500 mg L^-1, pH 10 and 45 min of HRT. By evaluation of nitrobenzene degradation, the best catalyst was selected as Fe₂O₃/γ-Al₂O₃. With the filling of Fe₂O₃/γ-Al₂O₃, the apparent kinetics on nitrobenzene removal can be expressed as the pseudo-first order reaction and nitrobenzene and TOC removals were 75.1% and 39.8%, respectively. With the introduction of catalyst, the nitrobenzene and TOC removals were significant increased by 13.7% and 12.6%, respectivly. After electrolysis, the biodegradablity of the effluent was greatly increased and BOD₅/COD_Cr increased from 0.06 to 0.307. In addition, intermediate and ultimate products were analyzed with HPLC and GC-MS, which included aniline, phenol and p-aminophenol, etc. The possible mechanism of nitrobenzene degradation includes the reduction of nitrobenzene at cathode, direct anodic oxidation and indirect oxidation by cathodic byproducts, and partial mineralization of nitrobenzene.Treatment of phenol wastewater by electrochemical heterogeneous catalytic process, the optimal conditions of phenol removal were determined as: applied potential of 25 V, Na₂SO₄ concentration of 1000 mg L^-1, pH 2.5 and 45 min of HRT. By evaluation of phenol degradation,更多还原