DNAPL污染对上海地区黏性土微观结构的影响

THE MICROSTRUCTURE OF CLAY INFLUENCED BY DNAPL POLLUTION IN SHANGHAI AREA

上海地区分布着大量的电器厂、制药厂、农药厂、印染纺织厂、化工厂等旧址,该类区域遗留着大量DNAPL污染物,造成了严重的水土污染问题。DNAPL的存在,可能对土壤可能产生结构演化作用,并影响着土壤的微观结构变化以及渗透特性。文中以上海地区浅部黏性土为研究对象,通过浸泡对比试验和扫描电镜试验,揭示了氯代烃污染与土相互作用后,导致土的微观结构发生明显变化。研究结果表明,受氯代烃污染后,上海浅部第2层土样发生明显的微观结构变化,孔隙渗透性能显著提高。4层土受氯代烃污染后则呈现出不同的结果,土体趋于密实,孔隙渗透性能降低。

In Shanghai,there are a large number of sites,such as electric equipment factory,pharmaceutical factory,agricultural pharmaceutical factory,printing and dyeing textile factory and chemical plant,etc.There are a large number of DNAPL left in these areas,causing serious water and soil pollution.In addition,the existence of DNAPL may have a structural evolution effect on soil,affecting the microstructure changes and permeability characteristics of soil.In this paper,the shallow soil in Shanghai area was taken as the research object.Through the contrast test by water immersion and scanning electron microscope,the interaction between hydrocarbon chloride pollution and soil resulted in obvious changes in soil microstructure have been revealed.After the soil was polluted by hydrocarbon chloridethe,soil samples in the second shallow layer of Shanghai have obvious changes in microstructure and the pore permeability was improved while the fourth shallow layer pore permeability decreased.