Treatment of high-concentration phenol wastewater by catalytic wet air oxidation
1. School of Environment, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2. State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China)
摘要 采用自制锰铈氧化物稀土催化剂间歇式反应釜催化湿式氧化(catalytic wet air oxidation,CWAO)处理高质量浓度苯酚废水,研究催化剂粒径、反应温度、系统氧分压、配水苯酚质量浓度、催化剂投加量、配水pH值等参数对湿式氧化处理效果的影响.研究表明,催化剂粒径〉200目时基本消除CWAO反应内扩散传质影响,较低温度下(100℃)CWAO可基本完全氧化处理苯酚废水,氧分压的提高仅加快了CWAO的反应进程,CWAO反应产生抑制与催化剂投加量和配水苯酚质量浓度之比相关,弱酸性条件最适于CWAO反应.催化剂失活的机理在于催化剂表面积碳.
Abstract:Catalytic wet air oxidation (CWAO) of high-concentration phenol wastewater using the prepared catalyst of manganese and cerium oxides was studied in a stirred batch reactor. The effects of the catalyst particle sizes, reaction temperature, oxygen partial pressure in the reaction system, phenol concentrations of the wastewaters, catalyst dosage, and pH value on CODCr removal efficiencies of the wastewater in the CWAO treatment were investigated, respectively. The experimental results show that the internal mass transfer of chemical reaction can be neglected when the catalyst particle size is up to 200 meshes in the experimental conditions. At lower temperatures ( 100 ℃ ) , the wastewater has been ef- fectively treated by CWAO reaction. Oxygen partial pressure only impacts the reaction rate. The final conversion of contaminants in the wastewater is correlated with the ratio of the catalyst dosage to the initial phenol concentration. The weak acidic condition is beneficial to the CWAO treatment of wastewater. The formation of carbonaceous deposits on the catalyst surface result in its deactivation during the CWAO reaction from the results of catalyst characterization.