中文摘要：

对饮用水中可同化有机碳和游离余氯对细菌生长的共同影响进行了研究。以添加有大肠杆菌的管网水为试验对象，加入不同质量浓度次氯酸钠溶液，结合流式细胞仪检测了72 h内不同时间点可同化有机碳（AOC）质量浓度和活性细菌浓度的变化情况。结果表明：在AOC初始质量浓度为168.44 μg/L的条件下，添加次氯酸钠后可同化有机碳质量浓度出现波动，是其他有机物氧化造成的；活细菌浓度在未添加余氯的情况下呈增长趋势，而在添加余氯的情况下整体呈下降趋势，且最终的活性细菌浓度与初始余氯质量浓度呈负相关。研究表明，在添加适量余氯的情况下，细菌活性主要受到余氯的抑制作用，而AOC导致的细菌再生长能力相对较弱。

英文摘要：

This paper aims to introduce our research findings on the combined effects of the assimilable organic carbon （AOC） and residual chlorine on the activities of bacteria in drinking water. In proceeding with our work, we have added Escherichia coli in the distribution system to the water samples and used them as an experimental target. And, then, we have added sodium hypochlorite to the water samples to make the initial concentrations of the residual chlorine equal to 0.3 mg/L and 0.6 mg/L. On the other hand, the water sample added with no sodium hypochlorite can also be used as the contrast group. The experiment was supposed to last 72 hours, during which period the flow cytometry can be used as a basic experimental method to test the changing situation of the concentrations of AOC and the living bacteria, which can be determined with a batch growth of natural microbial consortium. The concentration of the living bacteria can then be worked out by the bacteria stained with SYBR Green Ⅰ and the mixed dye of SYBR Green Ⅰ and propidium iodide. The initial concentration of AOC has been found to be 168.44 μg/L in all of the water samples. When we added the sodium hypochlorite, the concentration of AOC would be found obviously fluctuated, which tends to be caused by the oxidation of some kinds of organic carbon. The concentrations of the living bacteria can then be found decreased from 1.06×10^5 cells/mL to 2.61×10^4cells/mL （0.6 mg/L residual chlorine） and 4.81×10^4cells/mL （0.3 mg/L residual chlorine）. The results of the experiments demonstrate that the final concentration of the living bacteria turns to be in positive correlation with the initial concentration of the residual chlorine. On the contrary, the concentration of AOC in the control group has been found behaving less fluctuated than the experimental group and the concentration of the living bacteria was increased from 1.06×10^5 cells/mL to 1.81×10^5 cells/mL in 72 hours. The results of our experiments suggest that when we use the moderat