真空紫外光催化降解水中双酚A及其机理研究  

Study on photocatalytic degradation of Bisphenol A(BPA)in water and its mechanism by vacuum ultraviolet light

作　　者：王媛[1,2] 兰豪[1] 刘宗豪 李晓蕊 张瑞雪[1,2] 黄家琰[1,2] WANG Yuan;LAN Hao;LIU Zong-hao;LI Xiao-rui;ZHANG Rui-xue;HUANG Jia-yan(College of Resource and Environmental Engineering,Key Laboratory of KarstGeoresources and Environment,Ministry of Education,Guizhou University,Guiyang 550025,China;Guizhou Karst Environmental Ecosystem Observation and Research Station,Ministry of Education,Guiyang 550025,China)

机构地区：[1]贵州大学资源与环境工程学院喀斯特地质资源与环境教育部重点实验室,贵阳550025 [2]贵州喀斯特环境生态系统教育部野外科学观测研究站,贵阳550025

出　　处：《安全与环境学报》2022年第2期1027-1034,共8页Journal of Safety and Environment

基　　金：贵州省留学人员科技活动择优资助项目((2018)0010)。

摘　　要：采用溶胶凝胶法制备二氧化钛(TiO_(2))薄膜光催化剂,比较不同初始质量浓度双酚A(BPA)在185 nm真空紫外光(VUV)下的降解和光催化降解。在此基础上,主要考察溶液初始pH值和水中常见阴离子对BPA真空紫外光催化降解的影响;通过自由基淬灭试验和对降解产物的分析推断可能的降解机理。结果表明,与VUV下BPA的降解相比,真空紫外光催化能显著促进高质量浓度BPA的降解。当初始质量浓度为100 mg/L时,BPA的真空紫外光催化降解速率常数是其在VUV下降解数率常数的1.65倍,其中光催化降解的贡献值可达39.4%。降解反应遵循准一级反应动力学规律。溶液初始pH值为6.19时,BPA降解最为迅速,pH值为3.54时次之,而pH值为9.30时降解最为缓慢。阴离子存在下,真空紫外光催化降解反应的准一级反应速率常数的变化趋势由大到小为k(NO_(3)^(-1))、k(CO_(3)^(2-))、k(Cl^(-1))、k(SO_(4)^(2-))、k(无)。羟基自由(·OH)是诱发BPA降解的主要活性物种,它与VUV一起作用于BPA分子,使其发生β断裂,进而得到降解。循环试验表明制备的TiO_(2)薄膜具有较好的稳定性和潜在的适用性。In this paper, titanium dioxide (TiO_(2)) membrane fabricated by sol-gel method was used as a photocatalyst to investigate the photocatalytic degradation of BPA under the irradiation of 185 nm vacuum ultraviolet light(VUV). Besides,the degradation of BPA with different initial concentration under the illumination of VUV alone was compared. Based on this, the effects of the initial pH value of the solution and different anions in water on the photocatalytic degradation of BPA in VUV were explored, respectively. According to free radical quenching experiments and analysis of degradation products, the possible photocatalytic degradation mechanism of BPA in VUV was proposed. The results showed that, compared with the degradation of BPA in VUV, the photocatalytic degradation of BPA at high concentrations in VUV was significantly improved.Moreover, the photocatalytic degradation of BPA abided by the pseudo-first-order reaction kinetics. The photocatalytic degradation rate constant of BPA with the initial concentration of 100 mg/L was about 1. 65 times of that of BPA in VUV, and the contribution value of photocatalysis was up to 39. 4 %. When the initial pH value of the solution was 6. 19, the photocatalytic degradation of BPA was the most rapid, and then followed by pH 3. 54 and pH 9. 30. In the presence of different anions, the changing trend of the quasi-first-order reaction rate constant of the photocatalytic degradation of BPA in VUV was as follow:k(NO;) <k(CO;) <k(Cl;) <k(SO_(2)) <k(blank).After the addition of scavenger of hydroxyl radical(·OH) such as methanol and isopropyl alcohol, photocatalytic degradation of BPA was obviously inhibited. It confirmed that OH was the principal actives pecies and played an important role in the degradation of BPA.Combining with the intermediates identified, it was proposed that OH could act on BPA molecules with VUV altogether, and then led to the β-cleavage of BPA molecules and further degradation. Meanwhile,the possible degradation pathway of BPA was predicted.Additionally,

关 键 词：环境工程学 TiO_(2)薄膜 双酚A 真空紫外光 光催化降解 降解途径 

分 类 号：X52[环境科学与工程—环境工程]