【作者】 吴俊峰；

【导师】 杨昌柱； 张敬东；

【作者基本信息】 华中科技大学 ， 环境工程， 2013， 博士

【摘要】 光电Fenton技术利用光、电、Fenton反应的协同作用，提高污染物的催化降解效果，此技术以其独特的优势已被广泛应用于难降解有机污染物废水处理研究。本论文以难降解有机污染物为对象，结合光电Fenton处理技术，开展以下两大部分研究：（1）研究发展了以MFe₂O₄（M=Zn，Cu，Co）作为光电类Fenton反应催化剂，用于降解苯并三氮唑（BTA）、4-硝基酚（PNP）、2,4-二氯酚（2,4-DCP）等难降解有机污染物。在此部分研究中，具有纳米颗粒结构的MFe₂O₄（M=Zn，Cu，Co）催化剂的制备均采用化学共沉淀法，并经TEM、XRF、XRD、比表面积（BET）等技术分析表征后，用于光电类Fenton降解反应中。首先研究了以ZnFe₂O₄作为催化剂利用光电类Fenton技术降解BTA过程。在加入0.067g·L^-1的ZnFe₂O₄催化剂时，最佳条件下，即0.15mmol·L^-1BTA，0.05mol·L^-1Na₂SO₄，外加电压-0.6V（vs. SCE，下同），初始pH为3.0，经紫外光照射降解180min后，BTA的去除率达到91.2%，COD去除率达到85.3%。其次研究了以CuFe₂O₄为催化剂的光电类Fenton技术降解PNP，在PNP初始浓度为0.1mmol·L^-1，Na₂SO₄0.05mol·L^-1，pH为3.0，0.067g·L^-1CuFe₂O₄，外加电压为-0.6V以及紫外光照射的条件下，经非均相光电Fenton技术降解180min后，PNP的去除率可达到92.8%，相应COD的去除率为81.4%。同时研究了以CoFe₂O₄为催化剂，利用非均相光电类Fenton技术降解2,4-DCP，结果表明在0.2mmol·L^-12,4-DCP，0.05mol·L^-1Na₂SO₄，外加电压-0.8V，pH为3.0，0.067g·L^-1CoFe₂O₄以及紫外光照射条件下，降解180min后，2,4-DCP的去除率可达到89.6%，COD去除率可达到84.2%。以上研究表明，MFe₂O₄（M=Zn，Cu，Co）可用作光电类Fenton反应的高效催化剂，基于此类催化剂的光电类Fenton技术是一项非常有用的有机污染物降解技术，对传统方法难降解的有机污染物均有较高的矿化效果。（2）研究了利用UV/Fenton技术及光电Fenton技术对污泥深度脱水液的处理。在研究UV/Fenton技术用于污泥脱水液处理时，利用表面响应法对最佳试验条件进行了优化，结果表明：在最佳试验条件下，即pH为3.0，H₂O₂投加量31.7mmol·L^-1，初始Fe²⁺浓度1.59mmol·L^-1(NH₂O₂:NFe²⁺=20:1)条件下，经紫外光照射反应50min后，COD去除率可达到60%，并且获得较高的H₂O₂利用率。同时TOC、TN、NH₄⁺-N、及TP去除率分别为46.4%、12.8%、65.6%和95%。（3）研究了光电Fenton技术用于污泥脱水液的处理，发现在优化条件下可获得比UV/Fenton技术更高的处理效率：在初始pH为3.0，H₂O₂投加量65.3mmol·L^-1，FeSO4投加量6.53mmol·L^-1(NH₂O₂:NFe²⁺=10:1)，外加电压为7.5V时，经光电Fenton技术处理20min后污泥脱水液的COD去除率可达到59%；同时，原污泥脱水液的TOC去除率为50.6%；TN及NH₄⁺-N的去除率分别为20.6%和73.6%；TP的去除率达到了96.5%。与传统的Fenton技术、UV/Fenton技术、电Fenton技术相比，光电Fenton技术可在短时间内获得一个较高COD去除率，而且TP的浓度也大幅度降低，不仅在污泥深度脱水液的快速处理方面具有很强的现实意义，也为光电Fenton技术在实际废水处理中的应用提供了实际的参考。更多还原

【Abstract】 Photoelectro-Fenton technology （PE-Fenton） can improve treatment effect oforganic pollutants via the synergistic effect of light, electric and Fenton process. Thistechnology has been applied widely in treatment of refractory organic wastewater. In thispaper, some refractory organic compounds were used as the target pollutants degradedwith PE-Fenton process. The main results were as follows.（1） MFe₂O₄（M=Zn，Cu，Co） were used respectively as Fenton like catalyst in thedegradation of refractory organic pollutants, such as1H-Benzotriazole （BTA）,p-Nitrophenol （PNP） and2,4-Dichlorophenol （2,4-DCP）, with heterogeneous PE-Fentonlike process. MFe₂O₄（M=Zn, Cu, Co） nano-particles were prepared by aco-precipitation process and characterized respectively with transmission electronmicroscope （TEM）, X-ray fluorescence analysis （XRF）, X-ray diffraction analysis （XRD）and BET surface area. Then the catalysts were applied in PE-Fenton like process. First,the degradation of BTA with the heterogeneous PE-Fenton like process was studied using ZnFe₂O₄nanoparticles as catalyst. Under the optimum conditions, just as0.15mmol·L^-1BTA,0.05mol·L^-1Na₂SO₄, the electrical potentials of-0.6V （vs. SCE）, pH3.0,0.067g·L^-1 ZnFe₂O₄and UV irradiation, the180min BTA removal efficiency reached91.2%and the COD value was reduced by85.3%. Secondly, CuFe₂O₄as catalyst was employedto remove PNP by the heterogeneous PE-Fenton like process. For0.1mmol·L^-1PNP with0.05mol·L^-1Na₂SO₄and pH3.0, under the optimum conditions, namely the electricalpotentials of-0.6V （vs. SCE） and0.067g·L^-1CuFe₂O₄,92.8%of PNP was removed after180min treatment under UV irradiation and the corresponding COD removal efficiencywas81.4%. Moreover, CoFe₂O₄as catalyst was employed to remove2,4-DCP by theheterogeneous PE-Fenton like process. It was found that high2,4-DCP removal efficiencyof89.6%was obtained in the optimum condition of0.2mmol·L^-12,4-DCP,0.05mol·L^-1Na₂SO₄, the electrical potential-0.8V （vs. SCE）, pH3.0,0.067g·L^-1CoFe₂O₄and UVirradiation after180min treatment. At the same time, the COD removal efficiency reached84.2%. The results demonstrated that MFe₂O₄（M=Zn，Cu，Co）could be used as high efficiency catalyst and the heterogeneous PE-Fenton like process was a very effectivemothod in the degradation of organic pollutants. Compared with traditional treatmenttechnologies, a higher mineralization efficiency was obtained for the refractory organicpollutants.（2） UV/Fenton process and PE-Fenton process were respectively applied to treatthe sludge liquor, produced in deep dehydration of conditioned sludge. In the treatment ofthe sludge liquor with UV/Fenton process, response surface method was used to optimizethe operation parameters. The results showed that about60%COD removal efficiencywas obtained by the UV/Fenton process after50min treatment under the optimumcondition, namely pH3.0, H₂O₂31.7mmol·L^-1, FeSO41.59mmol·L^-1(NH₂O₂:NFe²⁺=20:1)and UV irradiation. A higher H₂O₂utilization ratio was also obtained. At the same time,the TOC, TN, NH₄⁺-N and TP removal efficiency could reach46.4%,12.8%,65.6%and95%, respectively.（3） Moreover, higher treatment efficiency was obtained in the treatment of sludgeliquor by the PE-Fenton process than UV/Fenton process. Under the optimum condition ofpH3.0, H₂O₂concentration of65.3mmol·L^-1，FeSO4concentration of6.53mmol·L^-1(NH₂O₂:NFe²⁺=10:1), the electrical potentials of7.5V and UV irradiation, only20min wasneeded for the COD removal efficiency to reach59%. The removal efficiency of TOC,TN, NH₄⁺-N and TP could reach50.6%,20.6%,73.6%and96.5%, respectively.Compared with the traditional Fenton process, UV/Fenton process and electro-Fentonprocess, the higher COD removal efficiency was obtained and TP was also effectivelyremoved in a short time. Moreover, this study had realistic meanings and provided apractical reference for the application of PE-Fenton process in wastewater treatment.更多还原