膜生物反应器活性污泥酶活与磷脂脂肪酸分析

Enzymatic activities and phospholipid fatty acids analysis of activated sludge from a submerged membrane bioreactor

分析了不同污染负荷下膜生物反应器的运行效率,并运用酶活表征污泥活性,用磷脂脂肪酸(PLFAs)分析微生物种群结构及其分布特征.结果表明,膜生物反应器对COD,TP,TN,NH4+-N保持着高而稳定的去除率,不同有机负荷下去除率差异不大(P>0.05);磷酸酶活性在低污染负荷下最高,脱氢酶、β-糖苷酶在中低污染负荷时的活性比高污染负荷时高,脲酶及蛋白酶活性随负荷增加而升高;活性污泥PLFAs组成以单不饱和脂肪酸、饱和脂肪酸和支链脂肪酸为主,而多不饱和脂肪酸与环丙烷脂肪酸含量较少,特征脂肪酸的比值表明在反应器中好氧细菌占绝对优势;微生物的群落结构分析显示,活性污泥中好氧原核微生物为优势类群,其次是革兰氏阳性细菌及其他厌氧细菌,而真核微生物所占比例最低.

The performance of a submerged membrane bioreactor was evaluated, and enzymatic activities and phospholipid fatty acids of activated sludge from different pollution loads was assayed. The removal rates of COD, TN, TP and NH4^＋-N kept in high and stable levels and the differences were not significant under different pollution loads（P〉0.05）; the enzymatic activity of phosphatase was the highest under low pollution load, activities of dehydrogenase and β-glucosidase under low and middle pollution loads were higher than that under high pollution load, and activities of urease and protease increased with pollution load; monounsaturated PLFAs, saturated PLFAs and branched PLFAs were dominant PLFA types, while polyunsaturated PLFAs and cycloproply PLFAs were present with relative small amount and ratios of characteristic fatty acids showed that aerobic prokaryotes were the most important groups; analysis of microbial community structure revealed that aerobic prokayotes were predominant groups in activated sludge, followed by the gram-positive prokaryotes and other anaerobic bacteria group, and the percentage of microeukaryotes group was the lowest.