桂西北典型矿区周边水稻田土壤剖面汞分布特征及其影响因素  

Distribution characteristics of Mercuryand its Influencing Factors of Paddy Fields around the Typical Mining Areas in Northwest Guangxi

作　　者：刘芳慧 黄丹 钟聪 赵银军 林清 胡宝清 张新英 LIU Fang-hui;HUANG Dan;ZHONG Cong;ZHAO Yin-jun;LIN Qing;HU Bao-qing;ZHANG Xin-ying(Key Laboratory of Environment Change and Resources Use in Beibu Gulf,Ministry of Educ ation,Chinal Guangi Key Laboratory of Earth Surface Processes and lntelligent Simulation,Institute of Geography and Oceanography,Nanning Normal University,Nanning 530001,China)

机构地区：[1]南宁师范大学北部湾环境演变与资源利用教育部重点实验室/广西地表过程与智能模拟重点实验室,地理与海洋研究院,广西南宁530001

出　　处：《土壤通报》2020年第6期1342-1350,共9页Chinese Journal of Soil Science

基　　金：国家自然科学基金项目(41867049);广西自然科学基金项目(2016GXNSFBA380106,2018GXNSFAA281263);国家重点研发计划(2016YFC0502401)资助。

摘　　要：以桂西北典型矿区周边稻田土壤为研究对象,采集3个剖面样本测定不同深度土层土壤总汞含量及其不同形态汞含量,探讨了汞的剖面分布特征及其影响因素,并采用富集因子法探究了土壤重金属的来源。结果表明:3个土壤剖面不同深度土层的汞含量不同,同一剖面以亚表层汞含量较高;不同剖面离矿区越近同一深度土层的汞含量越高;离矿区较近土壤剖面的个别土层汞含量超过或接近农用地土壤筛选风险值,但3个土壤剖面不同土层汞含量平均值均未超过土壤管控风险值;而其中2个剖面表层土壤汞的生物有效性相对较高,具有潜在生态风险;土壤中的汞形态以铁锰结合态、腐殖酸结合态、残渣态为主;DC2剖面土壤汞含量主要受到外来源的影响,其余剖面汞含量主要受到地质背景影响;土壤pH、有机碳和磷均与土壤总汞含量无显著相关性,但却与个别形态汞含量具有显著相关关系。本研究认为研究区衡量汞生态地球化学风险既要考虑土壤母岩汞的背景值,又要考虑人为活动的影响,其中前者居于主导地位。The distribution characteristics of mercury(Hg) and its forms in soil profiles of the paddy fields in Northwest Guangxi were analyzed and the main influencing factors were discussed. The sources of heavy metals in soil were also explored by the enrichment factor method. The results showed that the vertical distributions of Hg contents were different among the three soil profiles, and the Hg content in the subsurface soil appeared relatively large. Soil parent material mainly affected the content of soil Hg, and mining activities also showed a certain influence on soil Hg pollution in the paddy fields. The average Hg content in the three soil profiles did not exceed the risk value of agricultural land. While it was larger than the risk value of agricultural land in some soil layers close to the mining area. Surface soil Hg had a higher bioavailability and potential ecological harm among soil profiles. The iron-manganese bound state, humic acid bound state and residual state were the main forms of soil Hg, while the content of other form of Hg was lower. Soil mercury content in profile 2 is mainly affected by external sources, and the mercury content in other profiles mainly comes from geological background. Soil pH, soil organic carbon and total phosphorus had no significant correlations with soil total Hg content, but had significant correlations with several Hgspecies. In this study, it is believed that the background value of Hg related to parent rock in the study area is the most important controlling factor for assessing the ecological geochemical risk, while human activities play a secondary role.

关 键 词：土壤剖面 汞形态 垂直分布 生物有效性 影响因素 

分 类 号：X53[环境科学与工程—环境工程]