Hydrogeochemical Features and Genesis of Confined Groundwater and Health Perspectives for Sustainable Development in Urban Hengshui, North China Plain

Abstract

Groundwater in confined aquifers is the preferred water resource worldwide, and its hydrochemical quality is the premise for sustainable development. A systematic hydrogeochemical research was conducted to get insight into the hydrochemical characteristics, genesis, and potential health threats of confined groundwater, based on analytical data of 45 groundwater samples collected from the urban area of Hengshui, Central North China Plain (NCP). The results showed most groundwater had desirable hydrochemical quality with a nearly neutral to slightly alkaline nature and dominantly soft-fresh Cl-Na face. Solute chemistry was governed by rock-water interaction including minerals dissolution and ion exchange, but out of the anthropogenic influences. All nitrogen pollutants and Zn were within the desirable limit, while F−, Mn, and Fe were beyond the desirable limit recommended by WHO in 28.9%, 15.6%, and 68.9% of samples. Overall chronic health risk from these toxic elements was identified in terms of various populations and mainly contributed by F−. Infants were more prone to the health risks of aqueous pollutants. Differential water supplies based on hydrochemical quality are recommended, and water improvement measures are suggested to be conducted aiming at the harmful fluoride in confined groundwater. The present research could provide valuable references for the health sustainability of confined groundwater utilization in sedimentary plains like NCP worldwide.

Accessible Phreatic Groundwater Resources in the Central Shijiazhuang of North China Plain: Perspective From the Hydrogeochemical Constraints

“…) versus TDS and anion weight ratio of Cl − /(Cl − + HCO 3 − ) versus TDS (Gibbs, 1970), are effective tools to visibly reveal the main processes governing groundwater chemistry in nature and have been widely used worldwide (Xiao et al, 2018;Luo et al, 2021;Xiao et al, 2021). As demonstrated in Figure 4, all sampled groundwaters were plotted in the rock dominance rather than precipitation and evaporation dominance, suggesting that the hydrochemistry of phreatic groundwater in the study area is significantly and dominantly controlled by water-rock interaction and out of the influence of evaporation.…”

“…For further illustrate the water-rock interaction processes, the end-member diagrams were employed to constrain the specific rocks involved in these natural mechanisms. Three main categories of rocks, namely evaporates, silicates and carbonates, can be identified from the end-member diagrams of Mg 2+ /Na + versus Ca 2+ /Na + and HCO 3 − /Na + versus HCO 3 − /Na + (Venkatramanan et al, 2017;Adeyeye et al, 2021;Xiao et al, 2021). As demonstrated in Figure 5, the phreatic groundwaters were dominantly situated in the silicates dominance and the transition between silicates and carbonates, implying silicates weathering and carbonates dissolution were the main sources of ionic substances for phreatic groundwater in the study area.…”