杭金衢高速公路沿线土壤重金属分布特征及污染评价

Distribution Characteristics and Pollution Evaluation of Heavy Metals in Hangjinqu Expressway Roadside Soil

为探讨高速公路对沿线土壤重金属污染的影响及林带的防护作用,于2016年6月,在杭金衢高速公路沿线的衢州市龙游县模环乡、金华市婺城区罗埠镇2个路段分别各设置3个采样断面,研究土壤重金属Pb,Cd,Ni,As和Cr的分布特征,并采用单项污染指数法和内梅罗综合污染指数法对其污染状况进行评价。结果表明,2个路段土壤重金属Cr含量最高,其次为Pb或Ni,最低为Cd。大部分采样点Pb,Cd,Ni,Cr含量明显高于金衢盆地土壤背景值。在0~160m范围内,随距路基变远,土壤中Pb,Ni含量总体呈先升高后降低趋势,而Cd,Cr呈逐渐降低趋势。6个断面中有3个断面土壤重金属整体处于轻度污染,2个处于中度污染,1个处于警戒级别。从不同林带宽度来看,40 m林带对高速公路沿线土壤重金属的防护效果最好。

Soil heavy metal content(Pb,Cd,Ni,As,Cr)was determined at Huanmo and Luobu village along Hangjinqu Expressway in Zhejiang province in June 2016.The results showed content of Cr was the highest,followed by Pb or Ni,and Cd at two villags.The contents of Pb,Cd,Ni and Cr of the most sampling sites were significantly higher than the background value of soil in Jinqu Basin.The trends of Pb and Ni cotnent were increased and then decreased with the distance from the expressway within 160 m,while that of Cd and Cr were decreased gradually.The conclusion indicated that forest belt of 40 m had the best protective effect on soil.