1.Research Center for Eco-Environmental Science,Chinese Academy of Science;2.Key Laborabory of Environment and Pollution Remediation,Institude of Soil Science,Chinese Academy of Science
Supported by the National Key R&D Program of China (No. 2021YFC1809100) and the National Natural Science Foundation of China (No. 72104231)
【Objective】It is important to study the soil environmental carrying capacity for soil pollution prevention and control in “The Action Plan for Prevention and Treatment of Soil Pollution”. Application of the estimation model of soil environmental carrying capacity could greatly improve the science content of the method of remediation target determination. 【Method】Taking an abandoned chemical site in Jiangsu Province as a case study, the spatial distribution and health risk assessment of three target pollutants (i.e. mercury, hexachlorobenzene, and chlorobenzene) were analyzed based on soil sampling and investigation in the site. The environmental carrying capacities and remediation target values for the pollutants were estimated using the soil environmental carrying capacity model. 【Result】 The results revealed that more than half of the sites had soil mercury and hexachlorobenzene excessing their risk screening values, with about 17% for chlorobenzene. The spatial distributions of all three pollutants were mainly dependent on the distribution of the sources and manufacturing processes. Importantly, a serious non-carcinogenic risk is suggested for mercury and chlorobenzene, while a serious carcinogenic risk for hexachlorobenzene. Results of the soil environmental carrying capacity estimation suggested that, under a normal scenario and taking the risk screening value as soil quality standard, there were areas in the site having an environmental carrying capacity for all three pollutants less than zero. This indicated that the contamination of those areas excessed the soil environmental carrying capacities. Under an optimistic scenario and taking the risk controlling value as soil quality standard, the whole site had environmental carrying capacities for all three pollutants greater than zero. This suggested that the site can contain more pollutants.【Conclusion】 The remediation target values calculated by the soil carrying capacity estimation model were 1.8 to 1.9 times higher than the corresponding risk screening and control values. This was due to the coefficient calibration during the processes of risk emergence, soil adsorption, and fixation of pollutants in the carrying capacity model. The results in this study can provide scientific and technical support for the development and application of soil environmental carrying capacity.
DING Shoukang, WANG Meie, WANG Yujun, LI Xiaonuo, CHEN Weiping. Estimation of Soil Environmental Carrying Capacity and Its Application in the Determination of Remediation Target in Contaminated Sites[J]. Acta Pedologica Sinica, DOI:10.11766/trxb202102090088,[In Press]