TiO2纳米管对水源水中MC-LR的光催化降解  

Photocatalytic degradation of microcystins-LR in source water using TiO_2 nanotubes

作　　者：邓一荣 赵璐[5] 苏雅玲[3] 钟音[1] 彭平安 肖荣波[2] DENG Yi-rong;ZHAO Lu;SU Ya-ling;ZHONG Yin;PENG Ping-an;XIAO Rong-bo(State Key Laboratory of Organic Geochemistry,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China;Guangdong Key Laboratory of Contaminated Environmental Management and Remediation,Guangdong Provincial Academy of Environmental Science,Guangzhou 510045,China;State Key Laboratory of Lake Science and Environment,Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 210008,China;University of Chinese Academy of Sciences,Beijing 100049,China;Guangzhou Research Institute of Environmental Protection,Guangzhou 510620,China)

机构地区：[1]中国科学院广州地球化学研究所,有机地球化学国家重点实验室,广东广州510640 [2]广东省环境科学研究院,广东省污染场地环境管理与修复重点实验室,广东广州510045 [3]中国科学院南京地理与湖泊研究所,湖泊与环境国家重点实验室,江苏南京210008 [4]中国科学院大学,北京100049 [5]广州市环境保护科学研究院,广东广州510620

出　　处：《中国环境科学》2018年第7期2498-2504,共7页China Environmental Science

基　　金：有机地球化学国家重点实验室开放基金资助项目(SKLOG-201618);国家自然科学基金项目(41501184,41601616);“十二五”国家科技支撑计划课题(2014BAC15B01)

摘　　要：采用"草酸+氟化铵"水相电解液体系通过阳极氧化法制备出了TiO_2纳米管材料,可有效光催化深度降解水源水中的微囊藻毒素(MC-LR).结果表明,阳极氧化电压为20V、组分配比为1/12mol/L H_2C_2O_4·2H_2O+0.5wt%NH_4F、电解液p H值为4、阳极氧化时间1~2h的条件下制得的纳米管形貌最清晰,孔径为50nm左右,管长为250~600nm;催化剂经过500~600℃的温度煅烧后对MC-LR的光催化降解效率相对较高;pH值在3.5或8左右时,有利于MC-LR的光催化降解,且光化学反应符合准一级反应动力学模型;MC-LR的光催化降解机理主要包括产生的强氧化性·OH自由基对Adda支链共轭双键、Mdha氨基酸单双键以及Adda支链中甲氧基等部位的攻击氧化和肽键的水解.In this work,TiO2 nanotubes was fabricated using anodization method with oxalic acid and NH4F solution.TiO2 nanotubes were used to photocatalytic degradation of microsytins-LR.The results showed that the morphology was the most highly ordered under the optimum anodic voltage of 20V,electrolyte composition of 1/12mol/L H2C2O4·2H2O+0.5wt%NH4F and anodization time of 1~2h.The pore size of nanotubes was around 50nm,and the length was 250~600nm.After annealing at the temperature of 500~600℃,TiO2 nanotubes showed a high photocatalytic ability for MC-LR under pH 3.5and 8.The photocatalytic reactions of MC-LR fit well with the pseudo-first order kinetics.We infer the possible degradation pathways of MC-LR involve not only the attack by hydroxyl radicals for the conjugated double bond and methoxy group in the Adda chain,as well as the conjugated system in the Mdha amino acid,but also the hydrolysis of peptide bonds.

关 键 词：TIO2纳米管 光催化 微囊藻毒素 降解机理 

分 类 号：X703.1[环境科学与工程—环境工程]