铁氧化物与丙酸对土壤中六氯苯厌氧降解影响

Effect of iron oxide and propionic acid on anaerobic degradation of hexachlorobenzene in soil

采用红壤性水稻土进行厌氧培养试验,设定灭菌对照、对照、丙酸、针铁矿、丙酸+针铁矿5个处理,分析铁氧化物、丙酸及其交互作用对土壤中六氯苯还原脱氯过程的影响及其反应机制.结果表明,培养40d后,5个处理的土壤中六氯苯可提取态残留量分别减少了26.9%、48.5%、63.4%、56.9%和72.9%;六氯苯还原脱氯主要生成五氯苯;添加丙酸在整个培养过程均显著促进六氯苯还原脱氯降解;添加针铁矿在培养前期促进六氯苯还原脱氯的效果明显;同时添加丙酸和针铁矿对促进六氯苯还原脱氯具有协同作用.

To investigate the effects of iron oxide, propionic acid and their interaction on the reductive dechlorination ofhexachlorobenzene （HCB） in soils and their reaction mechanisms, an anaerobic incubation experiment was conducted inHydragric Acrisols with five treatments： sterile control, control, propionic acid, goethite, and propionic acid ＋ goethite.Results showed that HCB residues for these five treatments decreased by 26.9%, 48.5%, 63.4%, 56.9%, and 72.9%compared to the initial quantities, respectively, after 40d of incubation, and pentachlorobenzene （PeCB） was the dominantproduct of HCB dechlorination. The addition of propionic acid significantly accelerated the reductive dechlorinationdegradation of HCB throughout the incubation. The application of goethite obviously promoted HCB dechlorination in theearly incubation period. The application of propionic acid and goethite resulted in a synergistic effect on accelerating thedechlorination of HCB.