Sources, transport and sinks of beryllium in a coastal landscape affected by acidic soils
Sources, transport and sinks of beryllium in a coastal landscape affected by acidic soils
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DOI：
10.1016/j.gca.2018.04.025
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发表时间：
2018-07-01
影响因子：
5
通讯作者：
Ojala, Antti E. K.
中科院分区：
文献类型：
--
作者：
Astrom, Mats E.;Yu, Changxun;Ojala, Antti E. K.
研究了含硫化物细粒沉积物排水后形成的酸性土壤（酸性硫酸盐土壤）中铍（Be）的源、输运和汇。这项研究包括确定的总丰度和形态的Be在各种固体和水性材料在陆地和河口的景观部分。一个主要特点是，尽管正常（背景）的含硫化物的沉积物中的浓度，从这些沉积物中的浸出后，O-2暴露和酸性硫酸盐土壤的发展是广泛的，浓度高达76亩L-1的土壤水，39亩L-1的径流和12亩L-1的低阶流。这些高Be浓度主要以溶液形式存在（即，通过1千道尔顿过滤器），并建模为由自由Be 2+主导。广泛的被释放内，从酸性硫酸盐土壤的淋溶控制的pH值，与4.0的临界值以下的Be浓度强烈增加。虽然斜长石和云母是最有可能在这些土壤中的主要载体，它建议，其他矿物，如氢氧化铍，铝氢氧化物携带Be，和Be硫化物的溶解在酸性沃茨的丰度的主要贡献者。在盐度较低的河口，当中和酸性富Be河水时，溶液中的Be主要转化为颗粒，悬浮颗粒物中盐酸羟胺可提取的Be高达17 mg kg（-1），乙酸铵EDTA可提取的Be高达4 mg kg（-1）。在相应的原始材料（酸性硫酸盐土壤的母质）在集水区，与这些试剂的中位数Be提取分别只有0.3和0.05毫克公斤（-1）。作为丰富的悬浮颗粒物最终成为底栖沉积物，被保存在总浓度方面，但在一定程度上的变化形态，包括释放氢氧化物和伴随的清除有机物和颗粒表面。(C)2018爱思唯尔有限公司版权所有
Beryllium (Be) sources, transport and sinks were studied in a coastal landscape where acidic soils (acid sulfate soils) have developed after drainage of fine-grained sulfide-bearing sediments. The study included the determination of total abundance and speciation of Be in a variety of solid and aqueous materials in both the terrestrial and estuarine parts of the landscape. A major feature was that despite normal (background) Be concentration in the sulfide-bearing sediments, the Be leaching from these sediments after O-2-exposure and acid sulfate soil development were extensive, with concentrations up to 76 mu g L-1 in soil water, 39 mu g L-1 in runoff and 12 mu g L-1 in low-order streams. These high Be concentrations were mainly in the solution form (i.e., passing a 1 kilodalton filter) and modelled to be dominated by free Be2+. The extensive Be release within, and leaching from the acid sulfate soils was controlled by pH, with a critical value of 4.0 below which the Be concentrations increased strongly. Although plagioclase and mica were most likely the main carriers of Be within these soils, it is suggested that other minerals such as Be hydroxides, Al hydroxides carrying Be, and Be sulfides are the main contributors of the abundance of dissolved Be in the acidic waters. When the acidic and Be-rich creek water was neutralized in the estuary of relatively low salinity, the dominating solution form of Be was removed by transformation to particles, reflected in the suspended particulate matter that had hydroxylamine hydrochloride extractable Be up to 17 mg kg(-1) and ammonium acetate EDTA extractable Be up to 4 mg kg(-1). In corresponding pristine materials (parent material of the acid sulfate soils) in the catchment, the median Be extractability with these reagents were only 0.3 and 0.05 mg kg(-1), respectively. As the Be-rich suspended particulate matter ultimately became benthic sediment, the Be was preserved in terms of total concentrations but underwent to some extent changes in speciation, including release from hydroxides and concomitant scavenging by organic matter and particle surfaces. (C) 2018 Elsevier Ltd. All rights reserved.