可同化有机碳及氯浓度对给水管网中生物膜生长的影响

Influences of assimilable organic carbon on bio-membrane growth inside water supplying pipe

以北京市自来水集团有限责任公司第九水厂炭滤池出水为研究对象，通过中试规模的臭氧活性炭工艺控制和改变进入模拟管网水中的可同化有机碳（Assimilable Organic Carbon，AOC）及余氯浓度，确定AOC含量、余氯与给水管壁生物膜生长的定量关系。试验表明：AOC浓度对管网中生物膜的生长有显著的影响，在不加氯的条件下模拟管网进水AOC维持在100μg／L左右时，模拟管网中挂片生物量达到10^7CFU／cm^2量级；在进水AOC维持在40-50μg／L时，挂片生物量下降显著，维持在10^4CFU／cm^2量级。在加氯后挂片生物量不超过10^3CFU／cm^2量级，在余氯0．3～0．5mg／L下挂片生物量稳定在10^2CFU／cm^2量级，同不加氯时相比生物膜的生长得到很好的抑制。

The outlet water from the carbon filter in the No. 9 Waterworks in Beijing was taken as example to research for the ozone-activated carbon pilot plant experiment. The inlet AOC and residual Cl into the researched network were controlled to investigate the quantitative relationship of membrane growth and the above-mentioned factors. The result showed that the AOC level was evidently effective to the membrane growth inside the pipe. In the condition of no Cl was used, AOC in inlet water at about 100/μg/L or 40-50 μg/L, the hanging membrane would be at order of magnitude of 10^7 and 10^4 CFU/cm^2 respectively. In the condition of Cl was used, the hanging membrane would be less than order of magnitude of 10^3 CFU/cm^2. At residual Cl in level of 0. 3-0. 5 mg/L, the hanging membrane would be at order of magnitude of 10^2 CFU/cm^2 steadily. Cl could be effective to inhibit the membrane growth.