【摘要】 为掌握生活污水原水特性，明确化粪池对排水系统的潜在影响，对重庆主城区4个典型住宅小区化粪池的进出水水质进行了监测与分析。结果表明：化粪池进、出水的COD、BOD₅、TN、TP、NH₃-N浓度均值依次为373.83、200.45、64.85、3.95、38.55 mg/L和224.93、152.22、57.16、3.63、34.47 mg/L，经过化粪池后各指标依次降低了39.83%、24.06%、11.86%、8.10%、10.58%；进、出水BOD₅/TN、BOD₅/TP、BOD₅/COD均值依次为3.50、64.78、0.53和2.68、42.58、0.67，经过化粪池后BOD₅/TN、BOD₅/TP分别降低了23.43%、34.27%,BOD₅/COD则提升了26.42%，研究时段内各小区化粪池进水BOD₅/TN大于4的比例最高仅为40%，生活污水原水碳氮比普遍低于生物脱氮需求；有机物浓度在12:00—14:00和18:00—20:00相对较高，TN、TP、NH₃-N浓度则在07:00—09:00相对较高。化粪池会导致BOD₅/TN有所降低，并可能加强排水管渠中有机物的降解，但也可以促进水质均化，降低水质冲击负荷。更多还原

【Abstract】 To determine the characteristics of domestic sewage and clarify the potential impact of septic tank on the drainage system, the influent and effluent quality of septic tanks in four typical residential communities in downtown of Chongqing was monitored and analyzed. The average COD, BOD₅,TN, TP and NH₃-N in influent of septic tanks were 373.83 mg/L, 200.45 mg/L, 64.85 mg/L, 3.95 mg/L and 38.55 mg/L, respectively, and those in effluent were 224.93 mg/L, 152.22 mg/L, 57.16 mg/L, 3.63 mg/L and 34.47 mg/L, respectively, indicating that these indexes decreased by 39.83%, 24.06%, 11.86%,8.10% and 10.58% respectively after the septic tank treatment. The average ratios of BOD₅/TN, BOD₅/TP,BOD₅/COD in influent were 3.50, 64.78, 0.53, respectively, and those in effluent were 2.68, 42.58, 0.67,respectively, indicating that BOD₅/TN ratio and BOD₅/TP ratio decreased by 23.43% and 34.27%, and BOD₅/COD ratio increased by 26.42% after the septic tank treatment. The highest proportion of influent BOD₅/TN ratio greater than 4 was only 40%, indicating that the carbon to nitrogen ratio of raw water was generally lower than the requirement of biological nitrogen removal. The concentrations of organic matter were higher at 12:00-14:00 and 18:00-20:00, while TN, TP and NH₃-N were higher at 07:00-09:00.Septic tank resulted in the decrease of BOD₅/TN ratio to a certain extent, and might improve the degradation of organic matter in the drainage system. However, it also promoted water quality homogenization and reduced impact load.更多还原