Characteristics and evaluation on heavy metal contamination in Changchun municipal waste landfill after closure

In the present study, comprehensive investigation on the spot and typical investigation method were used to assess Mn, Zn, Pb, Cd, Cr, Ni, As and Cu level, pH value, organic matter, total nitrogen and total phosphorus contents in soil of Changchun municipal waste landfill. The results showed that soil in the closure area of Changchun municipal waste landfill was alkaline in nature and the average value of organic matter, total nitrogen and total phosphorus contents were lower than that in normal black soil in Changchun City of Jilin Province. Single factor indices of As, Pb and Cr content was > 1, where P(As) was 1.131, P(Pb) 1.061 and P(Cr) 1.092 mildly contaminated. In different sample spots but the same landfill time, the comprehensive Nemerow contamination indexes of 7a (5 #) and 7a (2 #) were P(2 comprehensive) = 1.176 and P(5 comprehensive) = 1.229. The performance value of of heavy metal contamination in soil was similar and there was a low ecological risk.