纳米ZnO膜光催化氧化测定化学需氧量的应用研究  

Determination of Chemical Oxygen Demand Values by Photocatalytic Oxidation Using Nano ZnO Film on Quartz

作　　者：陆华[1] 曲云鹤[2] 周天舒[3] 郑蕾[2] 施国跃[2] 

机构地区：[1]楚雄师范学院化学系,云南楚雄675000 [2]华东师范大学化学系,上海200062 [3]华东师范大学环境科学系,上海200062

出　　处：《华东师范大学学报（自然科学版）》2007年第6期62-68,96,共8页Journal of East China Normal University(Natural Science)

基　　金：国家自然科学基金(20675032);上海市青年科技启明星跟踪计划(44032660)

摘　　要：提出了一种利用石英管负载的纳米ZnO膜光催化测定化学需氧量的方法.通过添加无机强氧化剂K2Cr2O7提高光催化体系对有机物的降解效率,在光催化氧化有机物的同时,K2Cr2O7也会被纳米ZnO表面的光生电子还原为Cr（Ⅲ）,根据Cr（Ⅲ）浓度的变化量确定水样化学需氧量的值.实验结果表明,在50~1 000mg/L的COD范围内,Cr（Ⅲ）浓度的变化量与标准水样中的CODCr值成正比例关系,检出限为20mg/L.将该方法用于实际水样检测,分析时间短,减少了二次污染,光催化反应后水样无需后处理可直接进行测定,且与国家COD标准分析法具有好的相关性.A COD measurement by photocatalytic oxidation using nano ZnO film was investigated. K2 Cr2O7 was added into the solution to enhance the efficiency of photocatalytic degradation, and simultaneously K2 Cr2O7 was reduced to Cr（ Ⅲ ） by photogenerated electrons which were adsorbed on the surface of ZnO. The measuring principle was based on direct determination of Cr （Ⅲ） concentration which was proportional to the COD value. Under the optimized experiment condition, the application range was 50-1 000 mg/L, and the detection limit was 20 mg/L. The immobilization of photocatalyst on the supports could not only solve the problem of low recovery of the catalyst and hard separation from the solution,but also overcome its shortcoming of poor stability. Applying this method to the determination of real samples, it was found to be rapid and environmentally friendly. Additionally, the method proposed above for determination of COD was in excellent correspondence with values obtained by using the conventional method.

关 键 词：纳米ZNO K2Cr2O7 光催化 化学需氧量(COD) 

分 类 号：Q948[生物学—植物学]