Effects of dry-wet cycles on the properties of soil DOM and the release of heavy metals [干湿交替对土壤DOM特性及重金属释放的影响]

作者：Peng G.; Lv Y.; Ding Z.; Wang P.; Ding Y.^*; Shi Z.

来源：Chinese Journal of Environmental Engineering, 2021, 15(8): 2689-2700.

DOI：10.12030/j.cjee.202104038

• DOM properties
• Heavy metal contaminated agricultural soil
• Heavy metal release
• Soil dry-wet cycles

This study aims to elucidate the effects of dry-wet cycles on the properties of soil dissolved organic matter (DOM) and the release of heavy metals from a typical Cu- and Zn-contaminated agricultural soil, by employing the soil incubation experiments, optical analysis, and stirred-flow experiments. Results indicated that soil pH, DOM concentrations and DOM aromaticity increased with the increase of soil moisture contents. Soil dry-wet cycles had significant influence on DOM concentrations but had little impact on pH and SUVA254 values. Kinetic experiments of heavy metal release revealed that the release of Cu and Zn from the soil was more reluctant under higher soil moisture contents, while soil drying process promoted the release of Cu and Zn from the soil at the first wet-dry cycle. Further precipitation and drought would not affect the release of Cu and Zn, and different frequency and strength of wet-dry cycles had similar effects on the release of Cu and Zn. Moreover, under the same conditions, the release rate of Zn from soil was higher than that of Cu, and the effect of wet-dry cycles on the release of Zn was less compared to the release of Cu. The results of this study will contribute to providing basis for the effective remediation of heavy metal-contaminated soil.

• 出版日期2021
• 单位华南理工大学