River-Groundwater Exchanges, Bank Filtration, and Groundwater Quality: Ammonium Behavior
River-Groundwater Exchanges, Bank Filtration, and Groundwater Quality: Ammonium Behavior
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DOI：
10.2134/jeq1998.00472425002700060019x
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发表时间：
1998-11
影响因子：
2.4
通讯作者：
C. Doussan;E. Ledoux;M. Detay
中科院分区：
文献类型：
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作者：
C. Doussan;E. Ledoux;M. Detay
在许多国家，银行过滤水是饮用水生产的重要组成部分。在这种情况下，从冲积含水层抽出的大部分水来自邻近的河流。银行过滤通常被认为在数量和质量上都是有益的。然而，在某些情况下，银行过滤会对地下水质量造成有害影响。本文描述了这种情况，重点是铵(NH4)浓度。这些数据是在一个试验性的银行过滤地点收集的，该地点是沿着塞纳河(法国)的一个大井场的一部分。在这个地点，地下水沿着流线路径采样，河床沉积物的孔隙水用窥探器或通过离心法采集岩心样品。浅层河床沉积物的孔隙水中氨氮含量较高(>；30mgNH4·L-1)，而地下水中的氨氮浓度较低(≤为20mgNH4·L-1)，且在岸边较高。沉积物中NH4的高浓度与河流中较大的有机负荷和底栖生物群落对这种有机物的矿化有关。在影响NH4在多孔介质中迁移和滞留的各种机制中，冲积沉积物(Kd1~10×10-3m3 kg-1)甚至白垩岩(Kd=48×10-3m3 kg-1)对NH4的吸附似乎是有效的。这一点可以用一个与场地条件相适应的滞后NH4迁移模型来说明。NH4盐的沉淀可能不参与调节该地点的NH4浓度。
In many countries, bank-filtrated water is an important component of the drinking water production. In this case, most of the water pumped from the alluvial aquifers originates from the adjacent river. Bank-filtration is generally considered beneficial both quantitatively and qualitatively. However, in some cases bank filtration can cause deleterious effects to groundwater quality. This paper describes such a case, focusing on ammonium (NH 4 ) concentrations. The data were gathered at an experimental bank-filtration site which is part of a large well field along the Seine River (France). At this site, groundwater was sampled along a flow line path and pore water of river bed sediments was collected with peepers or by centrifuging core samples. The pore waters of the superficial river bed sediments have high ammonium concentrations (>30 mg NH 4 L -1 ) whereas, in the groundwater, these concentrations are lower (≤20 mg NH 4 L -1 ), with higher concentrations near the bank. The high NH 4 concentration in the sediment is related to the heavy organic load in the river and the mineralization of this organic matter by benthic microflora. Among the different mechanisms that influence NH 4 transport and retention in the porous medium, it emerges that sorption by the alluvial sediments (K d 1 -10 x 10 -3 m 3 kg -1 ), or even the chalk (K d = 48 x 10 -3 m 3 kg -1 ) seems to be effective in retaining NH 4 . This is illustrated by a model of NH 4 transfer with retardation adapted to the conditions of the site. Precipitation of NH 4 salts is probably not involved in regulating NH 4 concentration at this site.