泵闸建设对白莲泾河段水质的影响

Effect of pump-gateway engineering on water quality of Bailianjing River

2007年4月-2009年4月对上海白莲泾河段水体环境质量进行了调查,取黄浦江南码头上1个断面和白莲泾上的3个断面,于每月大、小潮当日采集各断面水样,获得了该河段的各项水质指标。2007年10月,白莲泾河道断流,泵闸工程实施。根据监测结果,以DO、BOD5、CODMn、TN和TP为指标参数,利用标准类别指数评价法对建闸工程施工活动的环境影响进行评价,结果发现:TN、TP是白莲泾河段的最主要污染指标,TN的权重系数均超过40%,甚至50%,均为劣Ⅴ类;TP的权重系数均超过10%,甚至30%,其含量是地表水Ⅳ类标准的0.8～5.6倍。总体上,白莲泾河段3个站点的水质劣于黄浦江站点,而施工前水质优于施工后。施工前,大潮期白莲泾河道IV类水比例为29%,较小潮期(8%)高出21%。建闸施工后,大小潮期间出现劣V类水的比例分别为87%和88%,潮汐对白莲泾河段并无显著影响。

The investigation on water quality of Bailianjing reach in Shanghai was carried out from April 2007 to April 2009. One cross-section at South Ferry of Huangpu River and three cross-sections at Bailianjing River were chosen and the survey covered both the spring and neap tides throughout the years. The damming of pump-gateway engineering on Bailianjing River was started in October 2007. Five water quality parameters which were dissolved oxygen （ DO）, biochemical oxygen demand （ BOD5 ）, permanganate index （ CODMn ）, total nitrogen （TN） and total phosphorous （TP）, were used to calculate the standard category index of 4 cross-sections. The results showed that the most important pollutants were TN and TP. Weight coefficients of TN in excess of 40% or even 50% , were over V grade and didn＇ t meet the corresponding water quality standard. Weight coefficients of TP were more than 10% or even 30% , and TP content was 0.8 - 5.6 times as high as National Grade IV. In general, water quality of three sites at Bailianjing River was inferior to that of Huangpu River, but the pre-construction water quality was better than building sluiced. Before pump-gateway was constructed, the proportion of IV grade water in Bailianjing River during spring tide period was 29%, 21% above that during neap tide period （8%）. After pump-gateway engineering started, the percentage of the water grade worse than V during spring and neap tide periods was 87% and 88% , showing that tides did not have any noticeable effect on Bailianjing River.