李晓东,曹云者,丁洁,王佳琪,王丽娜,杨宾.长期不同水分调控对污染场地土壤溶解性有机质含量及其结构特征的影响[J].环境科学学报,2021,41(8):3366-3373
长期不同水分调控对污染场地土壤溶解性有机质含量及其结构特征的影响
- Effects of long-term different water incubation on the content and structure characteristics of soil dissolved organic matter on contaminated sites
- 基金项目：内蒙古自治区科技重大专项（No.2019ZD001）；污染场地安全修复技术国家工程实验室开放基金（No.NEL-SRT201707）
- 李晓东
- 中国环境科学研究院环境基准与风险评估国家重点实验室, 北京 100012
- 曹云者
- 生态环境部土壤与农业农村生态环境监管技术中心, 北京 100012
- 丁洁
- 生态环境部土壤与农业农村生态环境监管技术中心, 北京 100012
- 王佳琪
- 中国矿业大学化学与环境工程学院, 北京 100083
- 王丽娜
- 1. 生态环境部土壤与农业农村生态环境监管技术中心, 北京 100012;2. 中国矿业大学化学与环境工程学院, 北京 100083
- 杨宾
- 1. 生态环境部土壤与农业农村生态环境监管技术中心, 北京 100012;2. 污染场地安全修复技术国家工程实验室, 北京 100015
- 摘要：为了考察不同水分调控下污染场地中土壤有机质和溶解性有机质（DOM）的演变过程，以2种冶炼厂重金属污染土壤为研究对象，通过恒温恒湿培养实验观察不同水分调控下土壤有机质和DOM的含量变化，并采用紫外-可见光谱和荧光光谱分析了土壤DOM的光谱特征.结果表明，水分调控180 d后，2种重金属污染土壤中有机质和DOM含量呈不同程度降低趋势，且随着水分含量增加，其降幅明显增加，最大降幅分别为33.28%和89.35%.水分调控过程中，土壤DOM中类蛋白物质最易发生降解，导致类富里酸和类腐殖酸的占比相应提高；随着水分含量增加，土壤DOM的芳香性提高，腐殖化程度升高，分子聚合度和分子量增大，最终导致DOM稳定性增强，上述结果有助于揭示水分诱导过程中DOM的变化对污染场地中重金属环境行为的影响.
- Abstract：To investigate the evolution process of soil organic matter and dissolved organic matter (DOM) under long-term different water incubation, we used two highly smelter-contaminated and aged soils to investigate the effects of different water incubation on the soil organic matter and DOM content by cultural experiment with constant temperature and humidity, and analyzed the spectral characteristics of soil DOM using ultraviolet-visible spectroscopy and fluorescence spectroscopy. The results showed that the organic matter and DOM content of the two soils decreased to varying degrees after 180 days of water incubation, and the decreasing range increased significantly with the increase of water content, with the maximum of 33.28% and 89.35%, respectively. The protein-like fraction in the soil DOM was especially prone to degradation during the water incubation, resulting in an increase in the proportion of fulvic-like fraction and humic-like fraction. Moreover, the aromaticity, humification degree, polymerization degree of molecular, and molecular weight of soil DOM increased with increasing of the water content, which ultimately leads to the enhancement of stability of soil DOM. This study is helpful to reveal the effect of soil DOM changes on the environmental behavior of heavy metals in contaminated sites under long-term different water incubation.
