腐植酸溶液的声化学降解研究

Degradation of humic acid in water in sonochemistry

采用频率为１．８ＭＨｚ的超声波在固定式声化学反应器内研究了声化学降解腐植酸的自由基氧化历程．通过采用 ＴＡ溶液作为 ＯＨ自由基捕获剂，毗啶溶液作 ＨＯ２自由基捕获剂，以及 ＫＩ溶液的 Ｉ２释放法分别确定出实验条件下反应溶液中 ＯＨ自由基的浓度为 １０－７Ｍ，ＨＯ２自由基浓度为１０－５Ｍ及 Ｈ２Ｏ２ 浓度为 １０－５．在此基础上研究了均相与多相催化条件下声化学降解腐植酸溶液的 ＴＯＣ削减情况．发现 ＣｅＯ２和 Ｃｕ２Ｏ催化作用下腐植酸的降解效率分别较均相条件下提高 ４０％和２０％．并就反应机理和反应动力学过程进行了描述．

Free radical oxidation mechanism of humic acid degradation under the irra diation of 1.8MHz ultrasound waves in a fixed sonochemical reactor was studied. It was found that using TA solution to trap the OH free radical ,pyridine to trap the HO2 free radical and KI solution to trap the H2O2 molecular, the concentration of OH and HO2 free radicals were 10-7 and 10-5 M, the H2O2 concentration was 10-5M. Based on these results, the homogeneous and heterogeneous catalysis sonochemical degradation of humic acid was also studied. It was found that in homogeneous solution the destruction rate of TOC was about 20%. While under the heterogeneous catalysis of CeO2 and Cu2O, the destruction rate of HA was higher than that in homogeneous solution by the percentage of 40% and 20% separately. The reaction kinetics process and mechanism were also de-scribed.