不同底物条件下金属离子螯合剂对厌氧消化的影响

Effect of Metal Chelating Agent on Anaerobic Digestion Under Different Substrates

借助气相色谱分析,研究了金属离子螯合剂在不同有机酸存在时对厌氧消化的影响.结果表明,螯合剂A的添加可以有效提高不同有机酸的甲烷产量和产甲烷速率,促进有机酸向甲烷的转化.当螯合剂A的添加量为10μmol/L时,丁酸、丙酸和乙酸的甲烷产量分别增加了19.8%、133.0%和45.2%.产甲烷的延滞期也明显缩短,最高产甲烷速率提高了4倍多.丁酸厌氧消化的4-8 d间,丁酸降解率达56%,同时,气相色谱未检测到乙酸的累积,说明丁酸转化为乙酸后,乙酸很快被产甲烷菌利用.螯合剂A对有机酸产甲烷的促进作用可从酶学上得到支持,以乙酸为例,添加10μmol/L螯合剂A时,污泥（VSS）中辅酶F420含量由空白实验的1.20μmol/g提高到1.52μmol/g.

Aided by GC analysis, the effect of metal chelating agent on anaerobic digestion under different substrates was investigated. The results showed that the addition of chelating agent A could greatly promote the methane production under different substrates and speed the conversion of organic acid to methane, especially for propionic acid. When the dosage of chelating agent A was 10 μmol/L, the methane production was, respectively, 19.8%, 133.0% and 45.2% for butyric acid, propionic acid and acetic acid. Also, the arrearage time of methane production was shortened and the production rate increased by 4-fold. During 4-8 d operation, the degradation rate of butyric acid reached 56 %. The accumulation of acetic acid was not detected by GC analysis, which demonstrated acetic acid converted from butyric acid was quickly utilized by methane producing bacteria. The increase in methane production due to the addition of chelating agent A could be supported by enzymology. Taking acetic acid as an example, the content of coenzyme 17420 in sludge increased to 1.52 μmol/g from 1.20 μmol/g due to the addition of 10 μmol/L chelating agent A.