Ag-TiO2光催化还原水体中硝酸盐同步氧化有机物的试验  

Experiment of Ag-TiO2 Photocatalysis Process for Nitrate Reduction and Synchronous Oxidation for Organics Removal in Water

作　　者：林超 吴磊[1] 郑天怡 付东王 杜智军 LIN Chao;WU Lei;ZHENG Tianyi;FU Dongwang;DU Zhijun(School of Energy and Environment of Southeast University,Nanjing 210000,China;Nanjing Water Planning and Designing Institute Co.,Ltd.,Nanjng 210000,China)

机构地区：[1]东南大学能源与环境学院,江苏南京210000 [2]南京市水利规划设计院股份有限公司,江苏南京210000

出　　处：《净水技术》2020年第7期52-58,共7页Water Purification Technology

基　　金：“十三五”国家科技重大专项资助项目(2017ZX07202004-005);“水污染控制与治理”科技重大专项成果,重污染区(武进)水环境整治技术集成与综合示范项目,太滆运河农业复合污染控制与清洁流域技术集成与应用课题

摘　　要：光催化反应体系中同时存在着起氧化作用的空穴与还原作用的光生电子,使得同步处理水体中的有机物与硝酸盐成为可能,同时,可避免空穴与光生电子复合而降低光催化反应效率。农业径流中无机氮主要以硝酸盐形式存在,且含有一定量的有机物。因此,选择光催化还原硝酸盐效率高与氮气选择性好的Ag-TiO2为催化剂,以葡萄糖和硝酸钾代表目标污染物,模拟农业径流,建立了共降解反应试验装置,探讨了pH、银掺杂量、Ag-TiO2投加量、反应时间等因素对有机物与硝酸盐去除效率的影响。结果表明,在pH值=4.5、Ag实际负载量为0.53 wt%,投加量为1 mg/L时,反应120 min,NO-3-N的去除率可达95.3%,气体转化率为76.3%,NO-3-N降解过程符合伪二级动力学方程,同时,有机物去除率达到了69.5%。In photocatalytic reaction system,there are both oxidized h+vb and reduced e-cb,which makes it possible to remove organic matter and nitrate in water simultaneously.At the same time,it can avoid the combination of h+vb and e-cb,which can reduce photocatalytic reaction efficiency.There are inorganic nitrogen and a certain amount of organic matter in agricultural runoff,and inorganic nitrogen mainly exists in the form of nitrate.Ag-TiO2 was selected as the photocatalyst,which had high photocatalytic reduction efficiency of nitrate and high nitrogen selectivity.Glucose and potassium nitrate were used as target pollutants,and a co-degradation reaction experimental device was established.The effects of pH value,silver doping amount,Ag-TiO2 dosage,and reaction time on removal efficiency of organic matter and nitrate were discussed.Results showed that when the initial pH was 4.5,actual loading of Ag was 0.53 wt%,the dosage was 1.0 mg/L,and reaction time was 120 min,removal rate of nitrate nitrogen(NO-3-N)could reach 95.3%,and gas conversion rate was 76.3%.Nitrate degradation process conformed to pseudo-second-order kinetic equation.At the same time,organic matter removal rate could reach 69.5%.

关 键 词：载银二氧化钛 硝态氮 有机物 共降解 光催化氧化还原 

分 类 号：TU991[建筑科学—市政工程]