Derivation case of Cr(VI) soil environmental criteria based on groundwater safety

Abstract

The heavy metal pollutant Cr (VI) has high toxicity and strong mobility, posing a great threat to groundwater safety. The current relevant soil standards often overlook groundwater safety. It is urgent to establish a Cr(VI) soil environmental reference value based on groundwater safety in order to provide support for the supervision of contaminated sites. In order to determine the calculation method of soil environmental reference value for groundwater protection that is in line with China’s characteristics, research and derivation of soil environmental reference value based on groundwater safety at home and abroad, and draw reference from foreign methods for formulating environmental reference value of pollutants based on groundwater safety. Taking Zhejiang clay loam, Jiangsu loamy sandy soil and Jilin loamy clay as research objects, the distribution coefficients of Cr(VI) in the three soils were obtained through indoor static adsorption tests. The soil parameters and aquifer-related parameters of the three soils were obtained through literature research, The soil screening level (SSL) method proposed by the United States Environmental Protection Agency in the Soil Screening Guidelines was adopted，based on groundwater quality standards (GBT14848—2017), a soil environmental reference value aiming at groundwater protection is obtained.The results show that the baseline values of Cr(VI) soil environment based on groundwater safety were 0.944 0.690, 0.514 mg/kg, respectively. The results are close to the reference values of foreign countries for the purpose of protecting groundwater safety. However, the differences of soil properties in each study area make the final base values different. Therefore, when improving the soil environmental quality system, local regulatory agencies should build a database of soil and aquifer parameters to help soil pollution control. The research results can provide scientific basis for deducing the environmental reference value of heavy metal soil based on groundwater safety in various regions of China.

Keywords

• environmental criteria
• cr(vi)
• ssl model
• groundwater protection
• distribution coefficient