复合菌群利用模拟APG协同FNA预处理剩余污泥水解液合成PHA

Synthesis of PHA by mixed microorganisms using simulative hydrolysate liquid from the excess sludge by APG combined with FNA pretreatment

为探究亚硝酸(FNA)预处理协同烷基糖苷(APG)处理剩余污泥水解液合成聚羟基烷酸酯(PHA)的可行性,本文启动接种两种不同污泥的序批式反应器(SBR)富集PHA产生菌,研究活性污泥复合菌群以模拟APG协同FNA预处理剩余污泥的水解液为底物的PHA合成效果;并采用批次合成实验,考察pH、C/N和C/P对PHA合成量的影响。结果表明:与接种污水厂二沉池污泥的反应器(SBR#1)相比,接种以葡萄糖为底物驯化成熟的产PHA混合菌的反应器(SBR#2)在30天时得到的PHA合成量较高;随着富集时间的推移,到117天时,接种污水厂二沉池污泥得到的PHA产生菌性能更优。PHA合成的最佳条件为:pH=8,C/P=100∶0.03,C/N=125∶1。在此条件下,PHA合成量最大,为57.34%。以实际FNA预处理协同APG处理剩余污泥水解液为底物时,PHA的累积合成量为24.43%。该研究结果可丰富污泥合成PHA技术方法,为污泥的处理和资源化利用提供技术支持。

In order to explore the feasibility of hydrolysate liquid from the excess sludge by alkyl polyglucose(APG)combined with free nitrous acid(FNA)pretreatment for synthesizing polyhydroxyalkanoate(PHA),two sequencing batch reactors(SBR)with different inoculums were used to enrich PHA-producing mixed cultures.The synthesis of PHA by mixed microorganisms with simulated hydrolysate liquid from the excess sludge by APG combined with FNA pretreatment as substrate was studied.The influence of pH,C/N and C/P on the synthesis of PHA was investigated with batch synthesis experiments.The results showed that:compared with SBR#1 inoculated with the sludge of the second settling tank,SBR#2 with the inoculated sludge from a long-running PHA enrichment using glucose as substrate could gain higher PHA yield at 30 days;at 117 days,SBR#1 with the inoculated sludge from the secondary settling tank had better performance.The optimal parameters for PHA synthesis were pH of 8,C/P of 100∶0.03,and C/N of 125∶1.Under this condition,the maximal PHA content was achieved,which was 57.34%.The cumulative PHA yield was 24.43%with actual hydrolysate liquid from the excess sludge by APG combined with FNA pretreatment as substrate.This research provides technical support for the recycling of sludge.