不同碳源驯化除磷污泥的除磷效果及菌群结构分析

采用SBR反应器,分别以乙酸钠、甘油、丙酸钠为单一碳源,在严格厌氧/缺氧条件下驯化培养反硝化除磷污泥,考察不同碳源对反硝化除磷效果的影响,并采用高通量测序技术研究了不同碳源除磷污泥的菌群结构,分析其中除磷菌所占比例. 结果表明,以乙酸钠、甘油、丙酸钠为碳源的各系统出水中,ρ(TP)平均值分别为0.79、0.98、0.29 mg/L,TP去除率分别为82.5%、79.2%、93.4%. 取自污水厂的种泥微生物多样性最高；其次为以甘油驯化的污泥和以乙酸钠与丙酸钠培养的污泥,二者表现出相似的多样性与菌群结构. 各反应器中的污泥在“纲”与“目”分类级别上分别均以β-Proteobacteria与Rhodocyclales占主导. 稳定期乙酸钠、甘油、丙酸钠为碳源的系统中的除磷菌所占比例分别为9.5%、8.0%、41.5%,以丙酸钠为碳源的系统中除磷菌所占比例最高. 对于厌氧/缺氧系统,与以乙酸钠、甘油相比,丙酸钠为碳源时系统的除磷效果更好,并且有利于除磷菌的富集. 

Phosphorus Removal Performance and Bacterial Community Structure of Denitrifying Phosphorus Removal Sludge Operated with Different Carbon Sources

In the present study, denitrifying phosphorus removal sludges with acetate, glycerol and propionate as the sole carbon sources were acclimatized in three sequencing reactors (SBRs) operated under strict anaerobic-anoxic conditions, and the sludges with different carbon sources were systematically investigated by high-throughput sequencing. Stable operation showed that propionate was the optimal carbon source, followed by acetate and glycerol, with average effluent phosphorus concentrations of 0.29,0.79 and 0.98 mg/L, corresponding to removal rates of 93.4%, 82.5% and 79.2%, respectively. The seed sludge from WWTP had the richest microbial diversity, followed by sludge fed with glycerol, acetate and propionate. Moreover, the two Volatile Fatty Acids (VFAs) feeding sludge (acetate and propionate) exhibited similar bacterial diversity and community structure. At the class level, β-Proteobacteria was most abundant for all the sludge samples. At the order level, Rhodocyclales that most phosphorus removal bacteria belonged to was the most dominant order for the samples from SBRs. Sequence local BLAST (Basic Local Alignment Search Tool) showed that the Ca. Accumulibacter-like PAO abundances of sludge with propionate, acetate and glycerol as carbon sources were 41.5%, 9.5% and 8.0% respectively during the stable operation; propionate feeding sludge had the highest abundance. Compared with acetate and glycerol, propionate showed priority for the enrichment of phosphorus removing bacteria in anaerobic-anoxic system, and the best carbon source for the EBPR.