三峡库区典型临江村镇排放污水的水质水量特征分析

Characteristics of Domestic Wastewater Quality and Quantity Discharged from Typical Villages and Small Towns by the Riverside in Three Gorges Reservoir Region

以重庆市石宝村镇为研究区域,通过现场采样及室内分析方法研究三峡库区典型临江村镇污水排放的水质和水量特征,对了解该类村镇污水污染状况及治理工程设计具有指导意义。结果表明,该类村镇排放的污水呈现出高氮、中磷、低有机物及低碳氮比的特征,无机态的氨氮和PO34--P是氮磷存在的最主要形态。1d内排放的污水流量和污水中各种污染物浓度随时间的变化在总体上趋势一致,但各时段的变化规律各有不同;不同功能日之间的污水流量和TP浓度相差较大,CODCr和TN变化不明显;由于月际间气温变化导致的用水活动变化和雨水的季节性分布,所研究的5—11月份的污水流量差异明显,主要污染物之间显现出类似的浓度变化规律,其中6、11月份的浓度明显高出监测期间内的其他月份。上述的流量和污染物浓度变化特征基本体现了三峡库区典型临江村镇居民的生活方式、作息规律及排水特点。

To understand the pollution condition of sewage from typical villages and small towns by the riverside in Three Gorges Reservoir and to conduct the wastewater treatment engineering design, the characteristics of domestic wastewater quality and quantity from Shibao village and small town in Chongqing were investigated by using on-site sampling and the experimental analysis from May to November in 2008. The results showed that the domestic wastewater discharged from this type of towns had the characteristics of high nitrogen, medium phosphorus and low organic matter concentration with the low carbon nitrogen ratio. Inorganic forms of nitrogen and phosphorus were dominant. The flow rate and the concentrations of different pollutants in the wastewater changed over time with a general identical tendency in a whole day, but the variations in the scale of hours differed. Wastewater flow rate and TP concentration showed obvious differences in different functional days. However, the concentrations of COD and TN had no significant changes. With the variation of water-consuming activities as a result of the monthly changes of temperature and the seasonal distribution of rain water, wastewater flow rate varied significantly in the study period （from May to November）, and the concentrations of main pollutants also exhibited a similar variation trend, the concentrations of pollutants in June and November were obviously higher than the other months in the monitoring period. The above mentioned variation tendencies of wastewater flow rate and pollutants concentrations basically reflected the characteristics of domestic wastewater discharging, the life styles and living schedules of local residents at typical villages and small towns by the riverside in Three Gorges Reservoir Region.