Evaluating the impact of percolated reclaimed water from river-channel reservoir on groundwater using tracers in Beijing, Northern China

Abstract

As an increasingly important aspect of water management, historical dry river-channels, ponds or lakes are operated for the storage of reclaimed water as a landscape with the need for reuse of water. However, the percolated reclaimed water may have an adverse effect on groundwater quality. The aims of this work are to evaluate the potential for using various groundwater constituents or characteristics as tracers of percolated reclaimed water, to clarify the groundwater hydrochemical process with the effect of the reclaimed water recharge, and to estimate the degree to which the infiltrated reclaimed water has mixed with the native groundwater. Results obtained by comparing analysis between the dry season and wet season are presented based on multivariate statistics analysis, correlation of hydrochemical elements, and stable isotopes. The groundwater with the impact of reclaimed water was clustered together with higher Cl, K and NH4–N concentrations, lower Ca concentrations and more enriched heavy isotopes using unprecedentedly 3D-biplot; The water types of the groundwater change from Ca–Mg–HCO3–Cl, via Ca–Na–Mg–HCO3–Cl to Na–Ca–Mg–Cl–HCO3 with increasing reclaimed water percolated into the groundwater; the most useful tracers for evaluation of the fate and mixing of reclaimed water are chloride ion and oxygen-18 and chloride ion is more accurate than oxygen-18 to quantify the recharge source of the groundwater from the reclaimed water; using a two-end-member mixing model to calculate the reclaimed water discharged into the groundwater, the proportion of reclaimed water in groundwater is up to 94% near the unlined riverbed and up to 43% far from it. These results demonstrate the potential of the combined application of multivariate statistics analysis, traditional hydrochemical analysis and isotopes to assess the percolated reclaimed water in the groundwater, especially using 3D-biplot to determine the spatial water quality changes defined by the different factors.

Molecular Responses of Dissolved Organic Matter to Anthropogenic Groundwater Recharge: Characteristics, Transformations, and Sensitive Molecules

“…In both SNWRA and RWRA, the number of total PMTs first increased and then decreased with the sampling depth and reached the peak at −80 m (Figure S5). Due to the presence of thick silty clay, the hydraulic connection between the aquifers at −80 and −150 m was weak . It is suggested that the surface water vertically entered the aquifer at −80 m after flowing through the aquifers at −30 and −50 m, and the infiltration was limited further downward.…”

“…The four aquifers are targeted aquifers for AGR. The aquifer sediments are dominated by gravel and sand, interlayered with silty clay, with increase in the proportion of silty clay in deep aquifers, and hydraulic conductivity of aquifer is around from 6.9 × 10 –4 to 1.2 × 10 –3 m/s . The vadose zone with relatively high permeability provides a vertical recharge pathway of surface water to shallow aquifers .…”

Numerical modeling of changes in groundwater storage and nitrate load in the unconfined aquifer near a river receiving reclaimed water

“…The solute transport model was developed based on the groundwater ow model. Cl − as a conservative solute has been generally used to trace and evaluate the impact of RW recharge on subsurface ow systems (Yu et al, 2016;Zhang and Yu, 2021). Cl − concentrations of RW are usually higher than that in natural water.…”

Research on scale inhibition law of high sulfate mine water based on response surface methodology

“…The pH value of mine water is often low, accompanied by a large number of ferrous ions, which increases the difficulty of its treatment. The water quality characteristics of mine water with high calcium and magnesium ions, high carbonate ions, and high sulfate ions will cause it to be very easy to scale in the circulating cooling system, where the formation of sulfate scale is difficult to be removed by conventional methods 1–8 …”

“…The water quality characteristics of mine water with high calcium and magnesium ions, high carbonate ions, and high sulfate ions will cause it to be very easy to scale in the circulating cooling system, where the formation of sulfate scale is difficult to be removed by conventional methods. [1][2][3][4][5][6][7][8] In circulating cooling water systems, the following types of scale may be generated: carbonate scale, sulfate scale, and silicate scale.…”