【摘要】 【目的】为分析输水距离与水质变化之间的关系,【方法】以北京市一段长约为20km的再生水输配管网为研究对象,监测沿程的水质指标变化规律。【结果】随着输水距离的增加,再生水管网中的总大肠菌群、粪大肠菌群和大肠埃希氏菌逐渐增加,而余氯浓度逐渐降低,微生物浓度与余氯浓度呈显著负相关（P<0.01）。此外,浑浊度和色度随着输水距离的增加逐渐升高,分别增加75.3%和6.9%,有机物指标总有机碳（TOC）、化学需氧量(COD_Cr)和紫外吸光度(UV₂₅₄)值逐渐下降。通过增加再生水厂内次氯酸钠投加浓度,可以有效提高再生水输配管网中的余氯浓度,从而提升水质的生物稳定性。【结论】建议将出厂水的游离余氯质量浓度控制在0.45mg/L以上,或总余氯质量浓度控制在0.60mg/L以上,可以保障再生水管网8km输配距离内粪大肠菌群浓度低于1000MPN/L,同时不会对再生水补给的河道水环境造成明显影响。研究对再生水输配管网的管理和微生物控制具有一定的指导意义,为提高再生水的水质稳定性和安全性提供了有益参考。更多还原

【Abstract】 [Objective] To analyze the relationship between distance of water diversion and variation in water quality, [Methods]this paper focused on a segment of approximately 20 km of reclaimed water transmission and distribution pipeline in Beijing,monitoring water quality indices along the pipeline. [Results] The results showed that total coliforms, fecal coliforms and Escherichia coli. in the reclaimed water network gradually increased with the increasing distance of diversion, while the residual chlorine concentration decreased, and the microbial concentration was significantly negatively correlated with the residual chlorine concentration（P<0. 01）.In addition, turbidity and color gradually increased with increase in water diversion distance, showing an increase of 75. 3% and 6. 9% respectively. Meanwhile, organic matter indices such as total organic carbon（TOC）, chemical oxygen demand(COD_Cr) and UV₂₅₄ gradually decreased. By increasing the dosage concentration of sodium hypochlorite within the reclaimed wastewater treatment plant, it was possible to effectively increase the residual chlorine concentration in the reclaimed water diversion and distribution pipeline,thereby enhancing the biological stability of water quality. [Conclusion] It is recommended to maintain a free residual chlorine mass concentration above 0. 45 mg/L or a total residual chlorine mass concentration above 0. 60 mg/L in effluent. This level of residual chlorine concentration could ensure that the concentration of fecal coliform bacteria within an 8 km reclaimed water distribution distance remains below 1 000 MPN/L, while also minimizing any significant impact on the water environment of the receiving river. The present study has significant implications for the management and microbial control of reclaimed water distribution networks, offering valuable insights to enhance the stability and safety of reclaimed water quality.更多还原