Elevated Manganese Concentrations in United States Groundwater, Role of Land Surface-Soil-Aquifer Connections
Elevated Manganese Concentrations in United States Groundwater, Role of Land Surface-Soil-Aquifer Connections
复制标题
DOI：
10.1021/acs.est.8b04055
复制
发表时间：
2019-01-01
影响因子：
11.4
通讯作者：
Johnson, Tyler D.
中科院分区：
文献类型：
--
作者：
McMahon, Peter B.;Belitz, Kenneth;Johnson, Tyler D.
利用美国43334口威尔斯井的化学数据，研究了地表-土壤-含水层连接在造成锰浓度升高（>300 μ g/L）中的作用。地下水地下水中锰和溶解有机碳（DOC）的浓度升高与浅，缺氧的地下水位和土壤中富含有机碳，这表明土壤来源的DOC支持锰的减少和动员在浅层地下水。锰和DOC浓度较高，附近的河流比远离河流，这表明河流来源的DOC也支持锰动员。人为氮也可能影响地下水中锰的浓度。在美国东北部部分缓冲性差的土壤中，锰浓度升高的样品中约有40%的pH值< 6 and elevated concentrations of nitrate relative to samples with pH >= 6，这表明肥料中铵的氧化产生的酸性补给有助于锰的流动。估计有260万人可能消耗锰浓度升高的地下水，其中最高密度发生在河流附近和有机碳丰富的土壤地区。从这项研究的结果表明，土地表层土壤含水层连接在生产用于人类消费的地下水锰浓度升高发挥了重要作用。
Chemical data from 43 334 wells were used to examine the role of land surface-soil-aquifer connections in producing elevated manganese concentrations (>300 mu g/L) in United States (U.S.) groundwater. Elevated concentrations of manganese and dissolved organic carbon (DOC) in groundwater are associated with shallow, anoxic water tables and soils enriched in organic carbon, suggesting soil-derived DOC supports manganese reduction and mobilization in shallow groundwater. Manganese and DOC concentrations are higher near rivers than farther from rivers, suggesting river-derived DOC also supports manganese mobilization. Anthropogenic nitrogen may also affect manganese concentrations in groundwater. In parts of the northeastern U.S. containing poorly buffered soils, similar to 40% of the samples with elevated manganese concentrations have pH values < 6 and elevated concentrations of nitrate relative to samples with pH >= 6, suggesting acidic recharge produced by the oxidation of ammonium in fertilizer helps mobilize manganese. An estimated 2.6 million people potentially consume groundwater with elevated manganese concentrations, the highest densities of which occur near rivers and in areas with organic carbon rich soil. Results from this study indicate land surface-soil-aquifer connections play an important role in producing elevated manganese concentrations in groundwater used for human consumption.