Harmful evaluation of heavy metals from soil layer to the groundwater: Take the Jilin Hunchun Basin as an example

The continuous enrichment of heavy metals in soils has caused potential harm to groundwater. Quantitative methods to evaluate the harm of heavy metals in soil to groundwater are lacked in previous studies. Based on the theory of groundwater circulation and solid-liquid equilibrium, a simple and easy-touse flux model of soil heavy metals migrating to groundwater is constructed. Based on groundwater environmental capacity, an innovative method for evaluating the harm of heavy metals in soil to groundwater is proposed, which has been applied in Hunchun Basin, Jilin Province, China. The results show that the fluxes of soil heavy metals into groundwater in the study area are Zn, Cu, As, Pb, Cd, Ni, and Hg in descending order. The content of heavy metals in groundwater (As, Hg, Cu, Pb, Zn, Ni, and Cd) in most areas has not risen to the threshold of environmental capacity within 10 years. The harm levels of soil heavy metals to groundwater in the most townships soils are at the moderate level or below. This evaluation method can quantify the flux of soil heavy metals into groundwater simply and quickly, determine the residual capacity of groundwater to heavy metals, evaluate the harm level of soil heavy metals to groundwater, provide support for relevant departments to carry out environmental protection of soil and groundwater, and provide a reference to carry out similar studies for related scholars.