Ecology and Environmental Sciences ›› 2026, Vol. 35 ›› Issue (3): 478-487.DOI: 10.16258/j.cnki.1674-5906.2026.03.014

• Research Article [Environmental Science] • Previous Articles     Next Articles

Simulating the Impact of Biochar-Derived Organic Matter on the Migration and Transformation of Mercury in Soil

GUO Tian(), YANG Yueqin, LI Weirui, XING Ying()   

  1. School of Chemistry and Materials Science, Guizhou Normal University, Guiyang 550025, P. R. China
  • Received:2025-07-18 Revised:2026-01-01 Accepted:2026-02-20 Online:2026-03-18 Published:2026-03-13

模拟生物炭源有机质对土壤汞迁移转化的影响

郭甜(), 杨跃琴, 李葳蕤, 邢英()   

  1. 贵州师范大学化学与材料科学学院贵州 贵阳 550025
  • 通讯作者: *E-mail: xy31034@163.com
  • 作者简介:郭甜(2000年生),女(穿青人),硕士研究生,主要从事环境污染化学方向的研究。E-mail: 2123151173@qq.com
  • 基金资助:
    国家自然科学基金项目(42163008);贵州省科技重大专项(黔科合重大[2025]002);贵州师范大学学术新苗基金项目(黔师新苗[2022]25号)

Abstract:

Soil organic matter can significantly influence the migration and transformation of mercury through adsorption and complexation. However, current knowledge regarding the impact of different types of organic matter on soil mercury transformation remains limited. This study investigated the effects of amending soil with different biochar-derived organic matter components (fulvic acid, humic acid, tyrosine, oxalic acid, and tannic acid) on the migration and transformation of mercury using a laboratory incubation experiment. The results showed that both fulvic acid and oxalic acid treatments significantly increased the content of bioavailable mercury (dissolved and exchangeable mercury, and carbonate-bound mercury) in the soil compared to the control. The methylmercury content in the pore water of the control was 1.73 ng·L−1, while in the organic matter treatments, it ranged from 1.10 to 44.38 ng·L−1. Compared to the control, the fulvic acid and oxalic acid treatments increased pore water MeHg by 30.50 ng·L−1 and 42.64 ng·L−1, respectively. The soil MeHg content in the control was 9.35 ng·g−1, and in the organic matter treatments, it ranged from 3.36 to 9.87 ng·g−1. Relative to the control, the tyrosine and humic acid treatments significantly reduced soil MeHg content by 64% and 46%, respectively. The distribution coefficients (Kd) of methylmercury in soils treated with different organic matters followed this order: CK≈ humic acid > tannic acid > tyrosine > oxalic acid > fulvic acid. The increase in methylmercury concentration in pore water under fulvic acid and oxalic acid treatments can be attributed to their strong binding affinity to Hg, which promotes mercury desorption from soil. This enhances mercury bioavailability and facilitates methylmercury formation. In contrast, tyrosine and humic acid treatments markedly reduced mercury bioavailability and inhibited methylmercury formation, likely due to their strong mercury immobilization capacity. In summary, tyrosine and humic acid show potential for mitigating mercury migration risks in contaminated soils, whereas fulvic acid and oxalic acid may increase such risks to some extent.

Key words: soil, pore water, organic matter, total mercury, methylmercury

摘要:

土壤中的有机质能通过吸附、络合等作用显著影响汞的迁移转化行为,但不同有机质对土壤汞迁移转化影响的认识仍十分有限。通过室内培养试验研究添加不同生物炭源有机质(富里酸、胡敏酸、酪氨酸、草酸和单宁酸)对土壤中汞迁移转化的影响。结果表明:1)与对照相比,富里酸和草酸处理土壤中生物有效态汞的质量分数(溶解与可交换态汞和碳酸盐结合态汞)均显著增加;2)对照组孔隙水中甲基汞质量浓度为1.73 ng·L−1,各有机质处理孔隙水MeHg质量浓度在1.10-44.38 ng·L−1范围内。其中,富里酸和草酸处理土壤孔隙水中甲基汞质量浓度较对照分别显著增加了30.50 ng·L−1和42.64 ng·L−1;对照组土壤甲基汞质量分数为9.35 ng·g−1,不同有机质处理土壤甲基汞质量分数介于3.36-9.87 ng·g−1之间。其中,酪氨酸和胡敏酸处理土壤甲基汞质量分数与对照相比分别显著降低了64%和46%;3)不同有机质处理土壤的甲基汞分配系数Kd大小为:CK≈胡敏酸>单宁酸>酪氨酸>草酸>富里酸。富里酸和草酸处理后孔隙水甲基汞质量浓度显著增加,这是由于它们活性高,与汞反应后促进了土壤汞向孔隙水的释放,增加了土壤中汞的生物有效性并促进了甲基汞的生成。然而,酪氨酸和胡敏酸处理显著降低了汞的生物有效性并抑制了甲基汞的生成,这可能与它们对汞的强固定能力有关。综上,酪氨酸和胡敏酸在降低土壤汞污染的迁移风险中具有一定的潜力,但是富里酸和草酸会在一定程度上增加汞的迁移风险。

关键词: 土壤, 孔隙水, 有机质, 总汞, 甲基汞

CLC Number: