Dynamic behaviors of water levels and arsenic concentration in shallow groundwater from the Hetao Basin, Inner Mongolia
Dynamic behaviors of water levels and arsenic concentration in shallow groundwater from the Hetao Basin, Inner Mongolia
复制标题
内蒙古河套盆地浅层地下水水位及砷浓度动态变化
DOI：
10.1016/j.gexplo.2012.06.010
复制
发表时间：
2013-12-01
影响因子：
3.9
通讯作者：
Tang, Xiaohui
中科院分区：
文献类型：
--
作者：
Guo, Huaming;Zhang, Yang;Tang, Xiaohui
地下水As浓度的时间变化对于理解As循环机制和制定有效的策略以可持续利用低As地下水是至关重要的。河套盆地浅层地下水砷含量的时间变化规律尚不清楚。从2006年到2010年，每年7月/8月采集一次地下水样本。2006年11月开展了另一次抽样活动。地下水位也得到了监测。结果表明，在以地下水灌溉为主的冲积扇前缘，12 - 4月水位高于5 - 9月水位。与此相反，最高水位出现在5 - 6月和11月，在平原地区，黄河水被用于灌溉。Na+、Cl-和HCO 3-的浓度在4年内相对恒定，但大多数威尔斯井的Ca 2+和Mg 2+浓度呈轻微下降趋势。尽管2006年大部分威尔斯井中砷的浓度低于2007年，但2006年至2010年之间砷浓度没有显著变化（p = 0.05）。浅层地下水采样11月从平坦的平原地区与地表水灌溉普遍表现出较高的As浓度比7月。这是由更多的还原条件，由于较少的氧气分散到含水层时，灌溉水淹没土壤，也许是不饱和区，证明了较低的氧化还原电位的浅层地下水在11月。mu-XRF结果表明，砷含量与铁含量在沉积物样品中的浅含水层有很好的相关性。As浓度和Fe浓度的时间变化之间的解耦最合理的解释预计是As（V）的还原解吸，由于As（III）和总As之间的类似变化趋势。皇冠版权所有（C）2012由Elsevier B. V.出版。保留所有权利。
Temporal variations in groundwater As concentration are crucial for understanding the mechanisms of As cycling and developing effective strategies for sustainable usage of low As groundwater in As-affected areas. Little is known about temporal variations in As concentration of shallow groundwater from the Hetao basin. Groundwater samples were taken once each year in July/August from 2006 to 2010. Another sampling campaign was carried out in November 2006. Groundwater tables were monitored as well. Results showed that water levels were higher during December-April than during May-September in the front of the alluvial fans where irrigation relied mainly on groundwater. In contrast, the highest water levels were observed in May-June and in November in the flat plain region where the diverted Yellow River water was utilized for irrigation. Concentrations of Na+, Cl-, and HCO3- were relatively constant over 4 years, although most wells showed slight decreasing trends in concentrations of Ca2+ and Mg2+. Although concentrations of As in most wells were lower in 2006 than in 2007, there were no significant changes in As concentration between 2006 and 2010 at p = 0.05. Shallow groundwaters sampled in November from the flat plain region with surface water irrigation showed generally higher As concentrations than in July. This was caused by more reducing conditions due to less oxygen dispersing into the aquifers when irrigation water flooded the soil and perhaps the un-saturated zone, as evidenced by the lower redox potential of shallow groundwater in November. Results of mu-XRF showed that As contents were well correlated with Fe contents in the sediment samples from the shallow aquifers. The most plausible explanation for the decoupling between temporal variation in As concentration and in Fe concentration was expected to be the reductive desorption of As(V), due to the analogical variation trends between As(III) and total As. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.