碱预处理污泥产酸效果及其生物群落研究

Studies on microbial structure and volatile fatty acids accumulation with different alkaline pretreatment

为了提高污泥水解酸化过程中的挥发酸产量,获取污水脱氮除磷所需的内碳源,以深圳市罗芳污水厂的二沉池污泥为研究对象,采用不同的碱量对其进行预处理。通过测定碱预处理污泥水解酸化过程中的挥发酸浓度,并采用聚合酶链式反应-变性梯度凝胶电泳(polymerase chain reaction denature gradient gel electrophoresis,PCR-DGGE)技术对参与碱预处理污泥水解酸化产酸过程的主要微生物种群进行分析,结果表明,当碱投加量为0.20 g NaOH/g VSS时,初始溶出的蛋白浓度为1 780 mg/L;水解酸化15 d时,挥发酸总量达到3 473 mg/L;参与产酸的主要细菌属于Firmicutes、Proteobacteria、Bacteroidetes三个门类。

Volatile fatty acids （VFAs） as internal carbon source of biological nutrient removal were improved in the process of hydrolysis and acidification. Different alkaline doses were used to pre-treat sludge for enhancing VFAs production, and sludge used in this study was from secondary settling tank of Luofang wastewater treatment plant in Shenzhen. In process of hydrolysis and acidification of alkaline pretreatment sludge, the concentration of VFAs was determined by gas chromatography （GC）. Polymerase chain reaction denature gradient gel electrophoresis （PCR-DGGE） was used to analyze the main microbial structure involved in hydrolysis and acidification process. The experimental results show that the total concentration of VFAs can reach to 3 473 mg/L when alkaline dose is 0.20 g NaOH/g VSS at 15 days, while the initial concentration of protein is 1 780 mg/L. Simultaneously, three microbial species, including Proteobacteria, Firmicutes and Bacteroidetes, participate in the hydrolysis and acidification reaction.