A2O工艺活性污泥中可培养丝状细菌的多样性

活性污泥法是应用最广泛的污水处理方法之一,但是由于丝状菌过度繁殖而引发的污泥膨胀是制约其发展的重大难题.本研究从A2O工艺城市污水处理系统的膨胀期活性污泥中分离培养出17株丝状细菌.对各菌株进行了16S rDNA测序和系统发育树分析,结果表明,这些分离的可培养丝状细菌均属于链霉菌属;利用rep-PCR指纹图谱技术进一步分析了所得菌种属内多样性,显示出活性污泥中链霉菌存在丰富的多样性.由于这些可培养丝状细菌与引起污泥膨胀的优势丝状菌(微丝菌)生理特征差别较大,不会在污水处理系统中过度繁殖,本研究向活性污泥中投加一定量的链霉菌分离菌株,发现部分菌株对污泥的沉降性能有明显改善作用,为污泥膨胀的防控提供了新的思路.

Diversity of Culturable Filamentous Bacteria in the Activated Sludge from A2O Wastewater Treatment Process

The anoxic-anaerobic-oxic (A²O) process is widely used in wastewater treatment plant, however, sludge bulking and foaming are the most frequent operational problems in this process. Activated sludge bulking is caused by the overgrowth of some types of filamentous bacteria, especially Microthrix parvicella. In the study, 17 strains of filamentous bacteria were isolated from the bulking sludge of A²O process using Gause's medium. The 16S rRNA genes of the 17 isolates were sequenced to analyze their diversity. The results showed all of the 17 isolates were Streptomyces. Further analysis of these strains by the repetitive sequence based on polymerase chain reaction (rep-PCR) technology showed that there was a high diversity in these isolated Streptomyces. The physiological properties of them were different from Microthrix parvicella. The settleability of activated sludge was improved when some of the isolates were inoculated.