State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, No. 8 Dayangfang, Beiyuan Road, Chaoyang District, Beijing, 10012, China; State Environmental Protection Key Laboratory of Ecological Effect and Risk Assessment of Chemicals, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; School of Environmental Science and Engineering, Guilin University of Technology, Guilin, 541006, China.
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, No. 8 Dayangfang, Beiyuan Road, Chaoyang District, Beijing, 10012, China; State Environmental Protection Key Laboratory of Ecological Effect and Risk Assessment of Chemicals, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
Environ Res. 2022 Oct;213:113504. doi: 10.1016/j.envres.2022.113504. Epub 2022 May 28.
The humic substances (HS) - mediated electron transfer process is of great significance to the reduction and degradation of pollutants and the improvement of soil quality. Different soil conditions lead to different characteristics of HS, resulting in differences in the electron transfer capacity (ETC) of HS. It is unclear how the environmental conditions in soil affect the ETC by affecting on HS. In this study, the response relationship of soil microenvironment, HS and ETC has been studied. The results show that the ETC follows the descending order of: Langshan > Nanchang > Anqing > Beijing > Guilin. There were significant differences in ETC in soil HS in different regions. There were significant differences in electron-donating capacity (EDC) in soil HS in different regions and depths. EDC in soil was higher than electron-accepting capacity (EAC), and on average, are 22.4 times higher than the EAC. The HS components of soils in different regions are different. The most significant differences were in tyrosine-like substances and soluble microbial by-products (SMPs). The five components of the soil HS from Langshan were the most different from those in other regions. There were differences in SMPs and humic-like substances in soils of different depths in Anqing and Guilin. ETC can be affected by the composition of HS components in different regions. The composition of HS at different soil depths in the same regions had little effect on ETC. SMPs can promote ETC and EDC, and tyrosine-like substance can promote EDC. Moisture content, pH and TOC are the main factors affecting the composition of HS components. This results can provide a research basis for the sustainable and safe utilization of agricultural soil.
腐殖质（HS）介导的电子转移过程对于污染物的还原和降解以及土壤质量的提高具有重要意义。不同的土壤条件导致 HS 具有不同的特性，从而导致 HS 的电子转移能力（ETC）存在差异。目前尚不清楚土壤中的环境条件如何通过影响 HS 来影响 ETC。本研究探讨了土壤微环境、HS 和 ETC 的响应关系。结果表明，ETC 的顺序为：狼山>南昌>安庆>北京>桂林。不同地区土壤 HS 的 ETC 存在显著差异。不同地区和不同深度土壤 HS 的电子供体能力（EDC）存在显著差异。土壤中的 EDC 高于电子受体能力（EAC），平均是 EAC 的 22.4 倍。不同地区土壤的 HS 组成不同。酪氨酸样物质和可溶性微生物产物（SMPs）的差异最为显著。狼山土壤的 HS 的五个组成部分与其他地区的差异最大。安庆和桂林不同深度土壤的 SMP 和腐殖质样物质存在差异。ETC 可能受不同地区 HS 组成成分的影响。同一地区不同土壤深度的 HS 组成对 ETC 的影响较小。SMP 可以促进 ETC 和 EDC，而酪氨酸样物质可以促进 EDC。含水量、pH 和 TOC 是影响 HS 组成成分的主要因素。该结果可为农业土壤的可持续和安全利用提供研究基础。
