改性花生壳活性炭吸附-催化臭氧氧化处理反渗透浓水

Adsorption-catalytic ozonation of RO concentrate in presence of modified peanut activated carbon

考察了改性活性炭吸附-催化臭氧氧化对炼化RO浓水中有机污染物的降解效果。结果表明,花生壳经H_3PO_4活化后具有较好的比表面积及孔径结构,再经Cu^(2+)、Mn^(2+)、Fe^(3+)溶液负载改性,得到花生壳活性炭催化剂,其中Cu^(2+)改性后的活性炭具有最大的比表面积。将不同的改性活性炭与臭氧组合处理RO浓水,COD去除率显著提高,表现为CuAC≥Mn-AC>Fe-AC>H_3PO_4-AC,偏碱性条件和提高活性炭投加量均利于活性炭吸附-催化臭氧氧化反应,且在30 min后COD去除率趋于平稳。当利用金属离子负载改性活性炭时,臭氧消耗率显著提高。其中,Cu-AC和Mn-AC吸附-催化臭氧氧化时臭氧的消耗率较高,COD去除率≥80%,出水COD<60 mg·L^(-1),达到国家一级排放标准。

The degradation of organic matter in RO concentrate by adsorption-catalytic ozonation was investigated in the presence of modified peanut activated carbon. The activated carbon was initially made from peanuts modified by H3PO4,followed by mixing,modifying,and loading with Cu2＋,Mn2＋,and Fe3＋solutions. The metalion loaded activated carbon showed high specific surface area and total pore volume,in particular the activated carbon modified by Cu2＋. As the modified activated carbon was used in the ozonation of the RO concentrate,the COD removal was enhanced significantly,which indicated Cu-AC ≥ Mn-AC 〉 Fe-AC 〉 H3PO4-AC. In addition,the COD removal efficiency of the combined ozonation and activated carbon adsorption was increased for basic samples with a high activated carbon dosage. As the reaction time went beyond 30 min,the COD removal increased slightly. Furthermore,the presence of metal-ion-loaded activated carbon significantly increased the ozone consumption. Among the three kinds of modified activated carbon,Cu-AC and Mn-AC consumed more ozone and had higher COD removal efficiencies of above 80%,which caused the below 60 mg·L-1effluent COD to meet the national discharge standard.