The influence and recovery of pipeline biofilm purification efficiency in closed aqueduct by pre-ozonation were studied by simulations with a BAR ( biofilms annular reactor ) and with addition of ozone. The results show that the amount of heterotrophic bacteria quickly reduces after ozonation and the inactivation ratio of ammonia oxidizing bacteria reaches 100%. Oxygen, produced by ozone decomposition, is conductive to biofilm update, so the biofilm is recovered quickly. Ammonia nitrogen degradation evidently reduces after ozone addition and, the oxidization ability of ozone leads to NH4+-N increasing. Removal efficiency drops from 81. 85% to 38. 49%, 17. 60% and -5. 50% respectively, as concentration of ozone is at 0. 7,1. 5 and 3. 2 mg/L. Moreover, significant nitrite nitrogen accumulation appears, and recovery of ammonia nitrogen removal is faster than that of nitrite nitrogen, which is recovered after 5 and 8 days respectively. Total organic carbon increases over inflow because oxidation caused by ozone, and water purification efficiency is recovered after 6 days.%采用稳定运行的环状生物膜反应器( biofilms annular reactor,BAR)模拟原水长距离输水管道水质净化过程,研究臭氧对管壁生物膜净水效能与生物净水功能恢复的影响.结果表明：臭氧处理后生物膜中异养菌数量迅速降低,氨氧化菌达到100%灭活,臭氧在水中分解生成氧气有利于生物膜更新,使生物膜迅速恢复.臭氧冲击明显降低了生物膜对氨氮的去除效果,臭氧自身的氧化能力也使氨氮略有增加,臭氧质量浓度为0.7、1.5、3.2 mg/L的反应器对氨氮去除率由对照组的81.85%分别降至38.49%、17.60%和-5.50%,并出现亚硝酸盐氮积累现象.生物膜对氨氮去除效能的恢复较亚硝酸盐氮快,分别在第5天和第8天恢复；臭氧对生物膜的氧化作用导致出水总有机碳高于进水,运行6d之后生物膜恢复净水效果.
展开▼
