3种短链脂肪酸对活性污泥储存PHA的影响

采用经乙酸钠驯化培养具有一定聚羟基烷酸酯(PHA)储存能力的活性污泥,考察乙酸、丙酸和丁酸3种短链脂肪酸,以及乙酸、丁酸分别与丙酸按1∶1、1∶2、2∶1比例组合成的6种混合酸作为碳源时对活性污泥中PHA的储存和转化的影响。实验结果表明,在3种短链脂肪酸中,以丁酸为碳源得到活性污泥PHA储存量最高,为40.53 mg/g;在混合酸中,乙酸与丙酸按1∶2组合时,系统PHA储存量最高,为773.4 mg/g。混合酸相对于单一的脂肪酸碳源更有利于活性污泥储存PHA。在混合酸总量一定的条件下,随着丙酸比例的增加,乙酸与丙酸混合比丁酸与丙酸混合更有利于微生物的PHA储存。

Impact of three short-chain fatty acids on PHA storage by activated sludge

Using acclimated activated sludge cultured with sodium acetate,the effect of short-chain fatty acids on polyhydroxyalkanoates(PHA) biochemical storage of microorganisms in activated sludge was investigated.Three kinds of short-chain fatty acids (acetic acid,propionic acid,butyric acid) and six kinds of mixed acids (the ratios of acetic acid/propionic acid were 1/1,1/2 and 2/1,respectively,and the ratios of butyric acid/propionic acid were 1/1,1/2 and 2/1,respectively)were chosen as carbon sources in the experiment.Results showed that using butyric acid as the carbon source could acquire highest storage capacity of PHA in the single short-chain fatty acids,reached 40.53 mg/g.For mixed acids,when the ratio of acetic acid/propionic acid was 1/2,the system's storage capacity of PHA was the highest,which reached 773.4 mg/g.In general,mixed acids were more beneficial to storage capacity of PHA than individual short-chain fatty acids.And under the same total amount condition,mixture of acetic acid and propionic acid was more conducive to PHA storage than mixture of butyric acid and propionic acid with the increase of propionic acid ratio.