【作者】 李悦；

【导师】 王鹏；

【作者基本信息】 哈尔滨工业大学 ， 环境科学与工程， 2008， 硕士

【摘要】 环境激素类有机污染物是一类影响及破坏生物体内分泌系统、神经系统和生殖系统的化学物质,其具有毒性大、结构稳定、较难降解等特点。因此寻求高效廉价的处理工艺已成为目前环境工程领域研究的热点。基于此,本研究开发了新颖的TiO₂/Ni光电催化氧化（PECO）工艺体系来处理水中的有机环境激素类物质-邻苯二甲酸二甲酯（DMP）。本文采用微波辅助法制备了TiO₂/Ni光电极,并优化得到最佳制备工艺为:微波反应体系温度90℃,微波辐照时间30min,n（H+）/n（Ti）=1:1,浸渍-提拉速率1.0mm/s,提膜15层,采用40℃恒温干燥箱作为层间干燥方式。采用X射线衍射（XRD）、扫描电镜（SEM）、傅里叶红外光谱仪（FT-IR）等结构分析方法对制备的光电极进行了表征,结果表明,微波辅助法制得的TiO₂溶胶具有完整的锐钛矿晶型,且在泡沫镍基体表面形成了连续、均匀的纳米膜。以自制的镍基二氧化钛（TiO₂/Ni）为光阳极,纤维状石墨毡材料（GF）为光阴极,饱和甘汞电极（SCE）为参比电极组建了TiO₂/Ni PECO工艺体系,以降解DMP为模型反应,通过实验获得此工艺体系的最佳运行参数:当紫外光强为42.6μW/cm2 ,DMP初始浓度为15mg/L时,外加偏转电压1.5V,曝氧速率40mL/min,光电极有效面积为4cm2 ,溶液pH值为6.0。在此条件下,DMP的去除率可达80%以上。进一步研究实验结果表明,TiO₂/Ni PECO体系对DMP有较高的矿化降解性能,矿化率达45.5%。且该体系光电之间存在协同效应。本文还研究探讨了TiO₂/Ni PECO工艺降解反应动力学和HO·的生成规律,通过研究各反应条件对降解动力学的影响,确定了反应级数和反应动力学常数。得到总反应速率常数公式为并确定了当DMP初始浓度一定时,影响TiO₂/Ni PECO氧化速率各因素的强弱排序为:催化剂面积A>紫外光强I>曝氧速率O₂>外加偏转电压V。HO·的生成规律实验证明了TiO₂/Ni PECO工艺较常见的TiO₂光催化工艺具有更强的氧化能力,本文研究结果为难降解的环境激素类物质提供了一种行之有效的处理方法。更多还原

【Abstract】 The danger of environmental hormone organisms that can destroy incretory、neural and genital system is terrible, and it is difficult to be degraded because of its longer stay time and higher toxicity. Photo catalysis of TiO₂ is applied in the treatment of water or wastewater, particularly in toxic wastewater treatment for its performance. With the aggravation of environmental pollution and enhancement of environmental consciousness, it is time to develop a highly effective treatment to water or wastewater. Based on the above problems, TiO₂/Ni photoelectrocatalytic oxidation （PECO） system was designed and its application in Dimethy Phthalate （DMP） treatment was studied in this research.Nanostructured TiO₂ porous film supported on nickel was prepared through microwave process. The optimum preparation parameters were as follows: microwave temperature 90℃, heating time 30min, n（H+）/n（Ti）=1:1, impregnation-pulling velocity 1.0mm/s, TiO₂-coated 15 layers and each layer was dried at 40℃in constant temperature ovens. XRD、SEM and FTIR Experimental results showed that TiO₂ crystal phase was mainly anatase,and nano-size film coated on the porous Ni surface equably.A PECO system was designed with the TiO₂/Ni photoelectrode as anode, GF （Graphite Felt） was used as cathode and SCE（Saturated Camel Electrode） was used as reference electrode. The technical parameters of this system were optimized. Under 42.6μW/cm² UV-A irradiation strength and 15mg/L DMP concentration, the optimum parameters were as follows: 1.5V voltage, 40mL/minO₂, 4cm2 TiO₂/Ni electrode and 6.0 pH value. Under the optimal conditions,degradation of DMP was up 80%.Experimental results showed that TiO₂/Ni PECO system and had a high mineralization rate.Mineralization of DMP could be 45.5%.Furthermore,current and UV-A irradiation in this system had a cooperation effect which enhances the degradation to pollutant.Kinetics and HO·generation of this TiO₂/Ni PECO system were studied based on the above experiments. The experimental results determined Kinetics orders and constants. And get a formula of total rate constant:If the initial concentration of DMP is a constant,The order of the effects sorted from strongness to weakness is: .The experiment of HO·proved that main oxide was HO·and degradation of DMP was mainly caused by it. This paper provided an effective disposal approach for the endocrine disruptor compounds.更多还原