常州不同城市用地类型地表污染物累积特征

Accumulation Characteristics of Surface Pollutants in Different Urban Land Use Types in Changzhou

针对面源污染物在城市复杂的不同下垫面具有不同累积特征的问题,以常州市中心城区为研究对象,采集居住用地、工业用地、交通用地、商业用地和文教用地等5种用地类别的64个样点地表累积物,测试累积物中总悬浮固体(SS)、氨氮以及全量和溶解态的COD,TP,TN含量,分析不同城市用地的污染物累积特征和居住用地、交通用地累积强度的季节变化差异,得到如下结果。1)交通用地各污染物的累积强度普遍高于其他功能用地,尤其是SS和全量COD,均值分别为59004.5和11179.7 mg/m2;商业用地上溶解态污染物均高于其他用地;文教用地、居住用地和工业用地上各污染物的累积强度较低。2)交通用地在2014年10月(秋季)和2015年3月(春季)的累积强度存在显著性季节差异,春季SS累积强度均值比秋季低约7.7%;全量TN和溶解态COD,TN,TP和氨氮的累积强度均值比秋季高约3.3%,49%,85%,61%和200%;居住用地的累积强度则没有季节差异。3)各类用地上颗粒态COD,TP和TN占全量的比例平均达86.5%,85.1%和71.1%,说明污染物主要吸附在颗粒态物质上,颗粒态污染物占大部分。因此,加大城市清扫力度有利于减少面源污染。4)商业用地单位颗粒物中COD和TN的含量均高于其他用地,均值分别为532.6和17.5 mg/g。交通用地COD,TP和TN的含量比最低,均值分别为212.2,0.86和2.9 mg/g。

In view of the problem that the non-point source pollutants had different accumulation characteristicson urban complex different underlying surfaces,the research took Changzhou central city as an example,collected64samples of surface pollutants on residential,industrial,traffic,commercial and cultural lands,tested thecontents of SS,ammonia nitrogen and total and dissolved COD,TP,TN of surface pollutants,analyzed theaccumulation characteristics of surface pollutants on different urban lands and the seasonal differences amongresidential and traffic lands.The results showed that the cumulative intensities of pollutants on roads weregenerally higher than other lands,especially SS and the total COD,with59004.5and11179.7mg/m2respectively.The cumulative intensities of dissolved pollutants on commercial lands were highest.The cumulative intensities ofpollutants on cultural,residential and industrial lands were low.The cumulative intensities in October2014(autumn)and March2015(spring)had significant seasonal differences on roads.Compared with autumn,the average cumulative intensities of SS in spring were reduced by7.7%,while total TN and dissolved COD,TN,TPand ammonia nitrogen were increased by3.3%,49%,85%,61%and200%.The cumulative intensities had no seasonaldifferences on residential lands.The average ratios of grainy to total COD,TP and TN were86.5%,85.1%and71.1%,which indicated that the main pollutants were adsorbed on the particulate matters,and more urban cleaninghelped reduce urban non-point source pollution.The average contents of COD and TN per unit mass of particulatematters on commercial lands were higher than that on the other lands with532.6mg/g and17.5mg/g,while that onroads were lower than that on the other lands with212.2mg/g(COD),0.86mg/g(TP)and2.9mg/g(TN).