Soil heavy metal occurrence forms and ecological risk assessment of a tailing pond in Nanjing
By collecting the surface soil samples of the tailings reservoir area,detecting and analyzing the total amount of heavy metals As,Pb,Cd,Cr,Cu and Zn and their different chemical forms in the samples,and the ecological risk of the soil in the mining area was analyzed by using the potential ecological risk index method,the risk assessment coding method,the secondary phase and primary comparison value method and the earthworm avoidance behavior test.The results indicated that:1)Minimum concentrations of As,Cd and Cu exceeded the background values of soil elements in Nanjing area,and the average values of the them were 3.5,6.7 and 9.3 times of the background values of soil elements in Nanjing area,respectively;2)The statistical results of potential ecological risk index show that the proportion of slight,medium,a little strong and strong potential ecological risks are 14.29％,50％,28.57％and 7.14％,respectively;3)The RAC values of the six heavy metals are all higher than 1％,and there is a certain risk,from the perspective of RAC and RSP,Cd has a very high risk of release and is the most important risk factor;4)The avoidance rate of earthworms in the soil with strong potential ecological risk points reached 100％,the polluted soil was not suitable for the survival of earthworms and the ecological risk was high,the avoidance rate of earthworms at other sites was less than 80％,and the ecological risk was low.
Heavy metalchemical formpollution assessmentecological risk
NETL
NSTL
万方数据
