O3/H2O2催化氧化—BAF处理煤气化渣淋洗废水OA

The leaching wastewater generated from oxalic acid leaching of coal gasification slag was selected as the research object,and an O3/H2O2 catalytic oxidation-biological aerated filter(BAF)coupled process was employed.The effects of initial pH,O3 concentration,catalyst dosage,H2O2 dosage,reaction time,and hydraulic retention time(HRT)on the removal of COD,ammonia nitrogen,and heavy metals in the wastewater were investigated.The experimental results show that under the optimal conditions of pH 7.0,an ozone mass concentration of 50 mg/L,an Al2O3 catalyst dosage of 200 g/L,and an H2O2 dosage of 1.25 mL/L,and a reaction time of 1.0 h,after O3/H2O2 catalytic oxidation treatment,the COD of the wastewater decreases from 164.0 mg/L to 96.0 mg/L,with a removal rate of 41.46%.Subsequently,the effluent from the O3/H2O2 catalytic oxidation process is further treated by the BAF process.At a HRT of 3.0 h,the effluent COD was 17.3 mg/L,the ammonia nitrogen concentration is 0.71 mg/L,and the contents of heavy metals such as As,Zn,Cr,and Hg are significantly reduced,meeting the Class Ⅲ water quality standards specified in GB 3838-2002.