当前位置: X-MOL 学术Appl. Geochem. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Comparison of arsenic concentrations in simultaneously-collected groundwater and aquifer particles from Bangladesh, India, Vietnam, and Nepal
Applied Geochemistry ( IF 3.4 ) Pub Date : 2008-11-01 , DOI: 10.1016/j.apgeochem.2008.07.005
A van Geen 1 , K Radloff , Z Aziz , Z Cheng , M R Huq , K M Ahmed , B Weinman , S Goodbred , H B Jung , Y Zheng , M Berg , P T K Trang , L Charlet , J Metral , D Tisserand , S Guillot , S Chakraborty , A P Gajurel , B N Upreti
Affiliation  

One of the reasons the processes resulting in As release to groundwater in southern Asia remain poorly understood is the high degree of spatial variability of physical and chemical properties in shallow aquifers. In an attempt to overcome this difficulty, a simple device that collects groundwater and sediment as a slurry from precisely the same interval was developed in Bangladesh. Recently published results from Bangladesh and India relying on the needle-sampler are augmented here with new data from 37 intervals of grey aquifer material of likely Holocene age in Vietnam and Nepal. A total of 145 samples of filtered groundwater ranging in depth from 3 to 36 m that were analyzed for As (1-1000 mug/L), Fe (0.01-40 mg/L), Mn (0.2-4 mg/L) and S (0.04-14 mg/L) are compared. The P-extractable (0.01-36 mg/kg) and HCl-extractable As (0.04-36 mg/kg) content of the particulate phase was determined in the same suite of samples, in addition to Fe(II)/Fe ratios (0.2-1.0) in the acid-leachable fraction of the particulate phase. Needle-sampler data from Bangladesh indicated a relationship between dissolved As in groundwater and P-extractable As in the particulate phase that was interpreted as an indication of adsorptive equilibrium, under sufficiently reducing conditions, across 3 orders of magnitude in concentrations according to a distribution coefficient of 4 mL/g. The more recent observations from India, Vietnam and Nepal show groundwater As concentrations that are often an order of magnitude lower at a given level of P-extractable As compared to Bangladesh, even if only the subset of particularly reducing intervals characterized by leachable Fe(II)/Fe >0.5 and dissolved Fe >0.2 mg/L are considered. Without attempting to explain why As appears to be particularly mobile in reducing aquifers of Bangladesh compared to the other regions, the consequences of increasing the distribution coefficient for As between the particulate and dissolved phase to 40 mL/g for the flushing of shallow aquifers of their initial As content are explored.

中文翻译:

孟加拉国、印度、越南和尼泊尔同时采集的地下水和含水层颗粒中砷浓度的比较

导致亚洲南部向地下水释放砷的过程仍然知之甚少的原因之一是浅层含水层中物理和化学特性的高度空间变异性。为了克服这个困难,孟加拉国开发了一种简单的装置,可以从完全相同的间隔收集地下水和沉积物作为泥浆。孟加拉和印度最近发表的依赖于针采样器的结果在这里得到了来自越南和尼泊尔可能的全新世年龄的 37 个灰色含水层材料的新数据的增强。总共 145 个过滤地下水样品,深度从 3 到 36 m,分析了 As(1-1000 马克/升)、Fe(0.01-40 毫克/升)、锰(0.2-4 毫克/升)和比较 S (0.04-14 mg/L)。P 可萃取物 (0.01-36 mg/kg) 和 HCl 可萃取物 As (0. 除了颗粒相的酸浸出部分中的 Fe(II)/Fe 比率 (0.2-1.0) 外,还在同一组样品中测定了颗粒相的 04-36 mg/kg) 含量。来自孟加拉国的针采样数据表明,地下水中溶解的砷与颗粒相中可提取磷的砷之间存在关系,这被解释为吸附平衡的指示,在充分还原的条件下,根据分布系数,浓度跨越 3 个数量级4 毫升/克。来自印度、越南和尼泊尔的最新观察表明,与孟加拉国相比,在给定的可萃取 P 水平下,地下水 As 浓度通常低一个数量级,即使只有以可浸出 Fe(II) 为特征的特别减少区间的子集)/Fe >0.5 和溶解的 Fe > 考虑 0.2 mg/L。与其他地区相比,为什么 As 在减少孟加拉国的含水层中似乎特别容易移动,但不试图解释为什么将颗粒和溶解相之间的 As 分配系数增加到 40 mL/g 以冲洗其浅层含水层的后果初始随着内容的探索。
更新日期:2008-11-01
down
wechat
bug