上海市青浦区2014—2019年水源水水质状况

Source water quality from 2014 to 2019 in Qingpu District, Shanghai

[背景]目前,上海市只有青浦区从淀山湖水系水源地和青草沙水库水源地同时取水。然而,对于这两大水源地水源水水质状况未见报道。[目的]评估青浦区3家集中式供水单位的水源水水质状况。[方法]收集青浦区2014年1月—2019年12月3家集中式供水单位93份水源水水质监测数据,比较超标检测项目。[结果]青浦区2014—2019年水源水中除氨氮及化学耗氧量(chemical oxygen demand,COD_(Mn))超标外,其他污染物指标均无超标。A、B、C三家水厂水源水的氨氮质量浓度中位数(P_(25)~P_(75))分别为0.16(0.10~0.24)、0.32(0.19~0.67)、0.31(0.20~0.50)mg·L^(-1),超标率分别为2.6%、32.1%、22.2%;COD_(Mn)中位数(P_(25)~P_(75))分别为1.83(1.66~2.04)、3.58(2.97~4.24)、3.76(2.97~4.15)mg·L^(-1),超标率分别为5.3%、71.4%、74.1%。A水厂水源水氨氮、COD_(Mn)超标率均低于B、C水厂(均P<0.0167)。A水厂水源水氨氮浓度和COD_(Mn)低于B、C水厂(均P<0.0167)。按水文期分析,枯水期A水厂水源水氨氮浓度低于B、C水厂(P=0.004、P=0.013)。不同水文期A水厂水源水COD_(Mn)均低于B、C水厂(均P<0.05)。[结论]2014—2019年的监测数据表明,青浦区水源水主要受氨氮和COD_(Mn)污染,且青草沙水库水源水水质优于淀山湖周边水系。

[Background] At present, only Qingpu District in the city of Shanghai draws water from water systems around Dianshan Lake and Qingcaosha Reservoir at the same time. However, there is no report comparing the source water quality between them. [Objective] This study evaluates the quality of source water of three centralized water supply plants in Qingpu District.[Methods] The monitoring data on 93 samples of source water were collected from three centralized water supply plants from January 2014 to December 2019 in Qingpu District, and the unqualified items were compared.[Results] Except for ammonia nitrogen and chemical oxygen demand(COD_(Mn)), other pollutant items did not exceed the national standard limits from 2014 to 2019 in Qingpu District. The ammonia nitrogen concentrations [M(P_(25)-P_(75))] in the source water of the three water plants A, B, and C were 0.16(0.10-0.24), 0.32(0.19-0.67), and 0.31(0.20-0.50) mg·L^(-1), respectively, and the corresponding unqualified rates were 2.6%, 32.1%, and 22.2%, respectively. The COD_(Mn) concentrations [M(P_(25)-P_(75))] were 1.83(1.66-2.04), 3.58(2.97-4.24), and 3.76(2.97-4.15) mg·L^(-1), respectively, and the unqualified rates were 5.3%, 71.4%, and 74.1%, respectively. The unqualified rates of ammonia nitrogen and COD_(Mn) in the source water of water plant A were lower than those of plants B and C(P < 0.016 7). The concentrations of ammonia nitrogen and COD_(Mn) in source water of water plant A were lower than those of plants B and C(P < 0.016 7). Regarding hydroperiod, in low flow period the level of ammonia nitrogen in the source water of water plant A was lower than those of plants B and C(P=0.004, P=0.013). In low, level, and high flow periods, the levels of COD_(Mn) in the source water of water plant A were all lower than those of plants B and C(P < 0.05). [Conclusion] The monitoring data of 2014 to 2019 reveal that the outstanding source water pollutants in the region are ammonia nitrogen and COD_(Mn), and the source water quality of Qingcaosha Reservoir is better than that of the water system around Dianshan Lake.