催化剂在Fe^0还原污水硝态氮中的催化作用  

Nitrate catalytic reduction by zero-valent iron from water over supported catalyst

作　　者：杨鑫[1] 李子富[1] 云玉攀[1] 王冬泠 赵军嫄 YANG Xin LI Zifu YUN Yupan WANG Donglin ZHAO Junyuan(School of Civil and Environmental Engineering, University of Science and Technology Beijing, Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants, Beijing 100083, China)

机构地区：[1]北京科技大学土木与环境工程学院工业典型污染物资源化处理北京市重点实验室,北京100083

出　　处：《环境工程学报》2016年第11期6147-6152,共6页Chinese Journal of Environmental Engineering

摘　　要：为降低水体中的硝态氮对环境的危害,提高污水处理厂出水水质,将催化剂运用到零价铁还原硝态氮反应中,分别对含TiO_2及Pd的催化剂进行了探索性实验。该实验以配置的KNO_3溶液为实验水样,在比较研究添加H^+、TiO_2/Al_2O_3催化剂、Pd/Al_2O_3催化剂去除效果的基础上,深入研究了负载量、载体类型、pH、溶解氧、共存离子等因素对去除效果的影响。结果表明,催化剂TiO_2/Al_2O_3对零价铁还原硝态氮的去除率有促进作用,水样pH=3.1时去除率为72%,产物主要为氨氮,应用性较差;而催化剂Pd/Al_2O_3在pH=3.1时去除率虽为43%,但产物以N_2为主。在负载量为5%的情况下,N_2转化率为76%,这对去除总氮有重要意义,并从电子转移角度探讨了该反应的反应机理,提出了活性氢(H*)为核心的机理模型。We herein report studies into the catalytic reduction of nitrate by metallic iron（ Fe^0） as a novel method of nitrate removal from water. Pd and TiO_2-based catalysts were employed throughout. A KNO_3 solution was used to evaluate the NO-3-N removal efficiency upon the addition of H＋,TiO_2/ Al_2O_3,and Pd /Al_2O_3. The effect of catalyst loading,support,pH,dissolved oxygen,and accompanying ions on nitrate removal were also investigated. The presence of TiO_2/ Al_2O_3 had a positive effect on nitrate removal. In addition,although the nitrate removal rate reached 72% at pH 3. 1,the dominant product was NH_4~＋-N,which has little practical application. Replacing TiO_2/ Al_2O_3 with Pd / Al_2O_3,a lower removal rate of 43% was obtained,however,the main product was N_2 gas. Furthermore,increasing the Pd loading to 5% increased the conversion rate of N_2 to 76%.Finally,the reaction mechanism was discussed on the basis of electron transfer,and a conceptual model of NO-3-N removal by zero-valent iron in the presence of a catalyst was given.

关 键 词：水处理 硝态氮 催化剂 TIO2 PD 

分 类 号：X703[环境科学与工程—环境工程]