Hydrologic controls on DOC, As and Pb export from a polluted peatland – the importance of heavy rain events, antecedent moisture conditions and hydrological connectivity
Hydrologic controls on DOC, As and Pb export from a polluted peatland – the importance of heavy rain events, antecedent moisture conditions and hydrological connectivity
复制标题
对受污染泥炭地 DOC、As 和 Pb 输出的水文控制——大雨事件、前期湿度条件和水文连通性的重要性
DOI：
--
复制
发表时间：
2015
期刊：
影响因子：
--
通讯作者：
H. Biester
中科院分区：
文献类型：
--
作者：
T. Broder;H. Biester
抽象的。沼泽地可以储存大量的铅（Pb）和砷（As），这些铅和砷来自人类排放的大气沉积。Pb和As的输出沿着溶解有机碳（DOC）从这些有机丰富的系统，但目前尚不清楚，水文（前）条件有利于他们的出口。这项研究结合了1年的降水，沼泽水位和孔隙水浓度的变化与沼泽排放和DOC，铁，砷和铅流浓度的监测。从这些数据，每年DOC，As和Pb的出口计算。DOC浓度范围为5至30 mg L−1，As浓度范围为0.2至1.9 μg L−1，Pb浓度范围为1.3至12 μg L−1，最高浓度出现在夏末。As和Pb浓度与DOC浓度呈显著正相关。通量强烈依赖于放电，作为40%的砷和43%的铅输出的时间在10%的时间与最高放电，指出了超比例的贡献，短时间，高放电事件的年度As，Pb和DOC的输出。指数增长的元素出口从沼泽解释连接额外的DOC，As和Pb池在顶片在水位上升，这是最明显的干旱后。铅，砷和DOC浓度在孔隙水提供的证据增加可溶性铅池泥炭层成为水文连接，而DOC和As的峰值浓度在径流滞后相比，铅。我们的数据表明，一个明显的沼泽特定的排放阈值为8 L s-1，这被认为主要取决于沼泽的大小和排水条件。超过这个阈值，元素浓度不会进一步增加，排放变得稀释。结合孔隙水和排放数据表明，As和Pb的出口不仅取决于降水量和排放量，但也对地下水位波动的频率和深度。将沼泽As和Pb的年输出量与元素库存量进行比较，结果表明As的年迁移量远大于Pb，分别占As和Pb总库存量的0.85 ‰和0.27 ‰。
Abstract. Bogs can store large amounts of lead (Pb) and arsenic (As) from atmospheric deposition of anthropogenic emissions. Pb and As are exported along with dissolved organic carbon (DOC) from these organic-rich systems, but it is not yet clear which hydrological (pre)conditions favor their export. This study combines a 1-year monitoring of precipitation, bog water level and pore water concentration changes with bog discharge and DOC, iron, As and Pb stream concentrations. From these data, annual DOC, As, and Pb exports were calculated. Concentrations ranged from 5 to 30 mg L−1 for DOC, 0.2 to 1.9 μg L−1 for As, and 1.3 to 12 μg L−1 for Pb, with highest concentrations in late summer. As and Pb concentrations significantly correlated with DOC concentrations. Fluxes depended strongly on discharge, as 40 % of As and 43 % of Pb were exported during 10 % of the time with the highest discharge, pointing out the over-proportional contribution of short-time, high-discharge events to annual As, Pb and DOC export. Exponential increase in element export from the bog is explained by connection of additional DOC, As and Pb pools in the acrotelm during water table rise, which is most pronounced after drought. Pb, As and DOC concentrations in pore water provide evidence of an increase in the soluble Pb pool as soon as the peat layer becomes hydrologically connected, while DOC and As peak concentrations in runoff lag behind in comparison to Pb. Our data indicate a distinct bog-specific discharge threshold of 8 L s−1, which is thought to depend mainly on the bogs size and drainage conditions. Above this threshold, element concentrations do not further increase and discharge becomes diluted. Combining pore water and discharge data shows that As and Pb exports are dependent on not only the amount of precipitation and discharge but also on the frequency and depth of water table fluctuations. Comparing the annual bog As and Pb export with element inventories indicates that As is much more mobilized than Pb, with annual fluxes accounting for 0.85 and 0.27 ‰ of total As and Pb inventory, respectively.
登录
查看更多内容
影响因子：
4.9
作者：
Broder, T.;Blodau, C.;Knorr, K. H.
通讯作者：
Knorr, K. H.
影响因子：
11.6
作者：
Evans, Chris D.;Jones, Tim G.;Freeman, Chris
通讯作者：
Freeman, Chris
影响因子：
4
作者：
Clark, J. M.;Heinemeyer, A.;Bottrell, S. H.
通讯作者：
Bottrell, S. H.
影响因子：
18.3
作者：
Fenner, Nathalie;Freeman, Chris
通讯作者：
Freeman, Chris