湿式氧化吡虫啉农药生产废水的MnOx-CeO2催化剂性能研究  

Catalytic Activities of MnO_x-CeO_2 Catalysts in Wet Air Oxidation of Pesticide Wastewater

作　　者：赵彬侠[1] 张小里[1] 李红亚[1] 刘林学[1] 金奇庭[2] 

机构地区：[1]西北大学化工学院,西安710069 [2]西安建筑科技大学环境与市政工程学院,西安710055

出　　处：《高等学校化学学报》2009年第5期965-970,共6页Chemical Journal of Chinese Universities

基　　金：陕西省教育厅专项科研计划(批准号:04JK235);陕西省自然科学基金项目(批准号:2004B28)资助

摘　　要：采用共沉淀法制备了用于湿式氧化吡虫啉农药废水的MnOx-CeO2系列催化剂,利用比表面测定仪(BET),X射线衍谢仪(XRD)和X射线光电子能谱(XPS)等对其进行了表征,并研究了不同Mn/(Mn+Ce)摩尔比对催化剂表面形态的影响以及催化剂表面形态与活性之间的关系.BET和XRD表征结果表明,Mn/(Mn+Ce)摩尔比为0.6时,催化剂晶粒尺寸最小,比表面积最大.XRD和XPS表征结果显示,Mn和Ce氧化物之间存在明显的相互作用,催化剂表面Mn的氧化态和化学需氧量(COD)随着组成的变化而变化,当Mn/(Mn+Ce)摩尔比为0.7时,催化剂表面出现高价锰氧化物,而且其化学吸附氧最多.用Mn/(Mn+Ce)摩尔比为0.7的MnOx-CeO2催化湿式氧化吡虫啉农药废水时,当催化剂用量为4 g/L,反应温度190℃,进水pH为7.0,氧分压1.6 MPa,搅拌速度500 r/min,反应60 min时,COD去除率最大为89.3%.A series of MnOx-CeO2 mixed oxide catalysts for catalytic wet air oxidation of pesticide wastewater from were prepared by co-precipitation method and used imidacloprid production. These catalysts were characterized by BET, XRD, XPS. The relationships between the surface structure and catalytic activity, and the effect of the manganese content [ i. e. the molar ratio of Mn/（ Mn ＋ Ce） ] on catalytic activity were researched. BET and XRD data revealed that the particle size of catalyst with n （Mn）/n （ Mn ＋ Ce） = 0.6 was the smallest, and specific surface area was the biggest in the series of catalysts. XRD and XPS techniques showed that the occurrence of significant interaction between Mn and Ce oxides, resulting in the evolution of textural, structural, oxidation state and the amount of chemisorbed oxygen with manganese content. The highest oxidation state of manganese oxide and the chemisorbed oxygen were present in the surface of MnOx-CeO2 mixed oxide catalyst at Mn/（ Mn ＋ Ce） = 0. 7. In the catalytic wet oxidation of pesticide wastewater from imidacloprid production, the most active catalyst was n （Mn）/n（ Mn ＋ Ce） - 0. 7. Using this catalyst, about 89.3 % COD removal was attained at catalyst loading of 4 g/L, temperature of 190 ℃, partial pressure of oxygen of 1.6 MPa and influent pH 7. 0 for 60 min.

关 键 词：催化湿式氧化 农药废水 MnOx-CeO2 CEO2 

分 类 号：O643.32[理学—物理化学]