Fe~0-厌氧微生物降解2,4-二氯酚的效应及机理

以2,4-二氯酚(2,4-DCP)为目标污染物,采用间歇试验,接种厌氧混合微生物,考察葡萄糖共基质条件下不同pH值时零价铁(Fe)0对2,4-DCP生物降解的效应,并对Fe0与厌氧微生物联合体系的作用机理进行探讨。结果表明:Fe0与厌氧微生物联合作用可提高2,4-DCP的降解效果,且中性或偏碱性环境下联合体系对目标污染物的促进效果较酸性环境明显,初始pH值为8时目标污染物的降解效果最好。Fe0在厌氧条件下腐蚀产生的OH-可有效平衡葡萄糖发酵产生的有机酸,使体系挥发性脂肪酸(VFA)的浓度维持在较低水平(300 mg/L),同时促使联合体系pH值上升从而利于目标物2,4-DCP的降解。Fe0在酸性环境的腐蚀较强,腐蚀产物以Fe2+为主,Fe3+含量较少。不同pH值时"Fe0+微生物"体系的COD去除率与目标物降解效果有一定相关性。

Fe0-Anearobic Microorganism Degradation of 2, 4-Dichlorophenol and Its Mechanism

Batch laboratory tests were done through inoculating the anaerobic mixed microorganism and co-substrate with glucose,to examine the effect of different pH on the process of anaerobic biodegradation of 2,4-dichlorophenol(2,4-DCP) in the presence of zero-valent iron(Fe0).The mechanism of combined system was discussed.Results indicated that the combined use of Fe0 and anaerobic microorganism could accelerate the degradation of 2,4-DCP,and the degradation effect of target contaminant in neutral or slightly alkaline condition was superior to acid condition.The optimum initial pH for the degradation of target contaminant was 8 in the combined system.OH-from Fe0 anaerobic corrosion balanced the organic acid produced by fermenting of glucose effectively,the concentration of volatile fatty acid(VFA) remained a lower level at 300 mg/L.pH of combined system gone up,and that in favor of degradation of 2,4-DCP.The corrosion of iron was strong in acid condition,ferrous ion was the main corrosive product from Fe0,and the content of ferric ion was very low.Removal rate of COD in combined system at different pH has a relation to the biodegradation of contaminant in some extent.