利用一种新型静态序批式蠕虫生物反应器处理剩余污泥,另设一个未加蠕虫的反应器作为对照。通过对比分析2个反应器中污泥的比减量速率、沉降性能、脱水性能和比好氧速率来研究蠕虫捕食对污泥性质的影响。实验结果表明,蠕虫具有良好的污泥减量效果,蠕虫加入后可使污泥比减量速率增加(0.15±0.02)mg/(mg·d)。蠕虫作用后污泥沉降性能明显改善,污泥容积指数(SVI)降低28.9%,胞外聚合物(EPS)含量减少和污泥絮体结构变得更加密实规则是污泥沉降性能得到改善的重要原因。蠕虫捕食后污泥脱水性能变差,污泥标准化毛细吸水时间和比阻分别增大2.45倍和1.16倍,推测主要是由污泥絮体平均粒径减小造成的。另外,蠕虫的存在会降低污泥的微生物活性,异养细菌、氨氧化细菌和亚硝酸盐氧化细菌的比好氧速率分别降低7.09%、7.84%和8.29%。
A new static sequencing batch worm reactor (SSBWR) was designed to treat excess sludge. Comparison experiments were carried out to investigate the effect on sludge reduction, sludge settleability, sludge dewaterability and microbial activity induced by Tubificidae' s predation. The specific sludge reduction rate by the predation of Tubifex tubifex was (0.15 ±0.02) mg/ ( mg .d) , demonstrating that Tubificidae had a good per- formance in sludge reduction. SVI decreased by 28.9% , indicating that the settleability of sludge was greatly improved by the presence of worm. The compact structure of sludge floc and the decrease of extracellular poly- meric substances (EPS) were the important factors contributing to the better settleability. The normalized capil- lary suction time (NCST) and the specific resistance to filtration (SRF) of sludge in SSBWR was 2.45 times and 1.16 times larger than that of initial excess sludge, respectively, showing a badly deterioration of sludge de- waterability, which could mainly result from a decrease in floc size. Microbial activity was also influenced by the worm' s predation. Specific oxygen utilization rates of heterotrophic bacteria, ammonia-oxidizing bacteria and ni- trite-oxidizing bacteria decreased by 7.09% , 7.84% and 8.29% , respectively.