Distribution of groundwater arsenic and hydraulic gradient along the shallow groundwater flow-path in Hetao Plain, Northern China

作者：Zhang Yilong; Cao Wengeng^*; Wang Wenzhong; Dong Qiuyao

来源：Journal of Geochemical Exploration, 2013, 135: 31-39.

DOI：10.1016/j.gexplo.2012.12.004

• Arsenic
• Hydraulic gradient
• Groundwater
• Flow path
• Hetao Plain
• Transect

This paper investigates how spatial distributions of groundwater arsenic (As) concentration and speciation are related to and are dependent on regional hydraulic gradients in a shallow aquifer containing elevated groundwater As in the Hetao Plain of Northern China. Groundwater samples (n = 165) were collected along three representative transects in the western, central and eastern parts of the Hetao Plain, spanning a wide range of total As concentration (036-916.7 mu g/l), arsenite concentration (0.2-719.4 mu g/l) and hydraulic gradients (0.11-23.31 parts per thousand.). The hydrodynamic conditions of the aquifer generally fall into the following four categories from the north to the south: Piedmont and discharge areas with high hydraulic gradient, runoff areas with weak or strong hydraulic gradient, and areas influenced by recharge from the Yellow River. Along all three transects, high groundwater As usually corresponds to low hydraulic gradients except for the discharge areas. In the runoff area in central Hetao Plain and the recharge area in southern Hetao Plain, the concentration of arsenic is more than 10 mu g/l when the hydraulic gradient is less than 0.8 parts per thousand. An empirical relationship between groundwater As concentration and groundwater hydraulic gradient can be established for the runoff area. The systematic changes in As concentrations and speciation along the groundwater flow path in the shallow groundwater support the notion that low hydraulic gradient of the groundwater is important in promoting As enrichment in groundwater.

• 出版日期2013-12
• 单位中国地质科学院