Assessing the impact of artificial recharge on groundwater in an overexploited aquifer: A case study in the Cheria Basin, North-East of Algeria

The Cheria region in Northeastern Algeria has been facing aquifer overexploitation by the agricultural sector and prolonged droughts,resulting in a considerable decline in groundwater levels.This study investigates the feasibility of implementing artificial recharge techniques to replenish the Eocene aquifer which serves as the primary water source in the Cheria region.A 3D transient numerical model,based on the finite difference method,was used to simulate groundwater flow from 2021 to 2031 using Visual MODFLOW Flex.During the modelling process,three scenarios were considered:(1)including pumping without a recharge,(2)recharge of the entire area through efficient infiltration without pumping,and(3)artificial recharge using river water infiltration basins at two sites,Draa Douamis sinkholes and Eocene limestone outcrops.The simulation results showed that aquifer exploitation without recharge caused significant drawdowns,which were 3 m to 7 m in the north-eastern part and 8 m to 12 m in the central and southern parts.In contrast,the second scenario,involving recharge without pumping,showed a rise in groundwater levels of 2 m to 2.7 m in the north-eastern part and 3 m to 3.62 m in the central and southern parts.The third scenario,employing artificial recharge,indicated a positive response to artificial recharge,with increased piezometric levels at the proposed sites,signifying a beneficial impact on the aquifer.These findings underline the potential of artificial recharge as a promising approach to address the groundwater depletion and environmental issues in the Cheria Basin.

Study on the Effect of Underground Temperature on the Adsorption Behavior of Chlorobenzene under Artificial Recharge Condition

[ Objective] The research aimed to study the effect of underground temperature on the adsorption behavior of chlorobenzene under artifi- cial recharge condition. [ Method] Based on the prior researches, combining actual condition of the artificial recharge test site, the adsorption be- havior of chlorobenzene under the background of artificial recharge was discussed. [ Reset ] The adsorption reaction of chlorobenzene correspon- ded with quasi-first-order and quasi-second-order kinetics equations at certain concentration. When temperature rose, reaction rate accelerated, and adsorption balance time shortened to 12 （0 ℃）, 10 （10 ℃） and 8 （20 ℃） h. The adsorption of chlorobenzene corresponded with isothermal adsorption model very well at different concentrations. When temperature ranged from 0 to 20 ℃, the adsorption amount of medium on chloroben- zene increased at equilibrium time. The maximal adsorption amounts calculated by Langmuir model were 20.747, 21. 505, 23.364 μg/g at 0, 10 and 20 ℃, respectively. [ Conclusion] The adsorption of chlorobenzene in aquifer medium was endothermic reaction, and the best season of artifi- cial recharne was in summer.

Clogging mechanisms and preventive measures in artificial recharge systems

The study aims to identify a suitable site for open and bore well in a farmhouseusing ground magnetic survey in south India.It also aims to define depth to granitoid and structural elements which traverse the selected area.Magnetic data(n=84)measured,processed and interpreted as qualitative and quantitatively.The results of total magnetic intensities indicate that the area is composed of linear magnetic lows trending NE-SW direction and circular to semi-circular causative bodies.The magnetic values ranged from-137 nT to 2345 nT with a mean of 465 nT.Reduction to equator shows significant shifting of causative bodies in the southern and northern directions.Analytical signal map shows exact boundary of granitic bodies.Cosine directional filter has brought out structural element trending NE-SW direction.Results of individual profile brought to light structurally weak zone between 90 m and 100 m in all the profile lines.Sudden decrease of magnetic values from 2042 nT to 126 nT noticed in profile line 6 between 20 m and 30 m indicates fault occurrence.Magnetic breaks obtained from these maps were visualized,interpreted and identified two suitable sites for open and bore well.Radially averaged power spectrum estimates depth of shallow and deep sources in 5 m and 50 m,respectively.Euler method has also been applied to estimate depth of granitoid and structural elements using structural indexes 0,1,2,and 3 and found depth ranges from<10 m to>90 m.Study indicates magnetic method is one of the geophysical methods suitable for groundwater exploration and site selection for open and borewells.

Improving Water Quantity and Quality Supply Security by Managed Artificial Recharge Technologies in the Lower Llobregat Aquifers Integrated into a Conjunctive Surface and Groundwater Management Scheme for Barcelona,Spain

The large concentration of human population,industry and services in the Metropolitan Area of Barcelona has to confront scarce water resources,serious seasonal and inter-annual variations and quality deficiencies in the sources.A large fraction of these water resources are in the medium-size Llobregat River basin and the remaining ones correspond to a surface water transfer,seawater desalination and wastewater reclamation.Groundwater dominated water resources availability before 1950.Afterwards,water supply has evolved progressively to integrated water resources management,which includes serious water quality concerns to deal with population density,river pollution,seawater intrusion in the main aquifer,and brine generation in the mid Llobregat basin due to old mining of saline minerals.The role of the alluvial aquifers has progressively evolved from being the main water source to reserve storage to cope with seasonal and drought water resources availability.River-enhanced recharge and artificial recharge are needed to assure enough groundwater storage before surface water becomes scarce and/or suffers a serious temporal loss of quality.Enhanced river recharge started in 1950.Treated river water injection in dual-purpose wells was put into operation in the early 1970s.Basin and pond recharge was added later,as well as a deep well injection barrier along the coast to reduce seawater intrusion and to allow increased groundwater abstraction in moments of water scarcity.There is a progressive evolution from solving water quantity problems to consideration of water quality improvement during recharge,with attention to emergent concern pollutants in river water and in reclaimed water to be considered for artificial recharge.Improvement of artificial recharge operation activities has been introduced and research is being carried out on the difficult behavior to degrade organic pollutants during infiltration and in the terrain.This paper presents the different activities carried out and presents the research activities,and comments on the economic,social and administrative issues involved as well.

Applicability of Artificial Recharge of Groundwater in the Yongding River Alluvial Fan in Beijing through Numerical Simulation

A groundwater transient flow model was developed to evaluate the applicability and effectiveness of artificial recharge scenarios in the middle-upper part of the Yongding River alluvial fan in Beijing. These scenarios were designed by taking into account different types of recharge facilities and their infiltration rate with the Middle Route Project for South-to-North Water Transfer（MRP） as the recharge water source. The simulation results suggest that：（1） the maximum amount of artificial recharge water, for scenario I, would be 127.42×106 m3 with surface infiltration facilities; and would be243.48×106 m3 for scenario II with surface infiltration and recharge wells under the constraint of the upper limit of groundwater;（2） with preferred pattern of recharge facilities, groundwater levels in both optimized recharge scenarios would not exceed the upper limit within the given recharge period; and（3implementation of the recharge scenarios would efficiently increase the aquifer replenishment and the groundwater budget will change from-54.11×106 to 70.89×104 and 183.36×104 m3, respectively. In addition, under these two scenarios groundwater level would rise up to 30 and 34 m, respectively, without increasing the amount of evaporation. The simulation results indicate that the proposed recharge scenarios are practically feasible, and artificial recharge can also contribute to an efficient recovery of groundwater storage in Beijing.

Application of digital techniques to identify aquifer artificial recharge sites in GIS environment

Because the groundwater is considered as the major source of 99%of all retrievable fresh water,optimization of its usage would be very crucial.Groundwater artificial recharge(GAR)using surface water is the recommended solution because that increases the aquifer storage.Detection of aquifer storage site is the first step in designing GAR projects.The main objective of this research is the identification of suitable GAR sites scattered in the Shahrekord plain,Chaharmahal-va-Bakhtiari province of Iran,using Boolean and Fuzzy logic.Data affecting GAR including ground surface slope,soil infiltration rate,vadoze zone thickness,electrical conductivity of the surface water,land-use,and stream network were collected.After provision of digital maps,they were classified,weighted,and integrated through Boolean and Fuzzy operators.The result revealed almost 4.25%of the whole plain area is appropriate for GAR based on Boolean.Also,4.79 and 17.94%of the plain area are suitable and rather favorable,respectively,based on Fuzzy.Finally,34 locations were introduced with priorities A,B,and AB as being potentially suitable for GAR.The relationship between geomorphology and suitable areas for GAR based on Boolean and Fuzzy method indicated that the majority of these areas were located on colluvial fans units.

A field study of advanced municipal wastewater treatment technology for artificial groundwater recharge

Field studies were conducted to investigate the advanced treatment of the municipal secondary effluent and a subsequent artificial groundwater recharge at Gaobeidian Wastewater Treatment Plant, Beijing. To improve the secondary effluent quality, the combined process of powdered activated carbon adsorption, flocculation and rapid sand filtration was applied, which could remove about 400 dissolved organic carbon （DOC） and 70% adsorbable organic halogens. The results of liquid size exclusion chromatography indicate that in the adsorption unit the removed organic fraction was mainly low molecular weight compounds. The fractions removed by the flocculation unit were polysaccharides and high molecular weight compounds. The retention of water in summer in the open recharge basins resulted in a growth of algae. Consequently, DOC increased in the polysaccharide and high molecular weight humic substances fraction. The majority of the DOC removal during soil passage took place in the unsaturated area. A limited reduction of DOC was observed in the aquifer zone.

A new hybrid framework of site selection for groundwater recharge

Since incorrect site selection has sometimes led to the failure of artificial recharge projects,it is necessary to increase the effectiveness of such projects and minimize their failure by employing new techniques.Therefore,the present research used a combination of decision-making models,numerical groundwater modeling and clustering technique to determine suitable sites for implementation of an artificial recharge project.This hybrid approach was employed for the Yasouj aquifer located in southwestern Iran.In the first stage,by employing an AHP decision-making model,hydraulic conductivity,specific yield,slope,land use,depth to groundwater,and aquifer thickness were selected from 21 criteria used in previous research.The selected criteria were then entered as input into the classical k-means clustering model.Using the output,aquifer was divided into seven different regions or clusters.These clusters were then matched with the land use map,and some of the abandoned land areas were selected as the final option for implementing the artificial recharge project.Finally,the MODFLOW code in the GMS software was used to simulate the groundwater level and cluster the sites selected,with regards to increase in groundwater level.Results indicated that the most significant increases in groundwater level(43 and 27 cm)were those of Clusters 2 and 6 in the northern and western parts of the aquifer,respectively.Therefore,this approach can be used in other similar aquifers in arid and semi-arid regions to select the best sites for artificial recharge and to prevent loss of floodwaters.

Groundwater recharge site suitability analysis through multiinfluencing factors(MIF)in West Bengal dry-land areas,West Bengal,India

Groundwater levels are gradually declining in basins around the world due to anthropogenic and natural factors.Climate is not the only factor contributing to change in groundwater levels,population growth and economic progress are leading to increased water demand.Areas used for agricultural irrigation are expanding,necessitating the use of artificial groundwater recharge as a method to sustain pumping and enhance storage.The present study delineates potential locations of significant groundwater resources that already exist using a geostatistical approach as a method to identify potential groundwater recharge zones.The Multi-Influencing Factors(MIF)technique was applied to determine the relationship between different landscape and climatic factors that influence groundwater recharge.Factors include topography,climate,hydrogeology,population,economic change,and geology.Integration of these factors enabled the identification of potential locations of groundwater suitable for artificial recharge efforts based on weights derived through the MIF technique.We applied these weights to derive a groundwater recharge index(GRI)map.The map was delineated into three groundwater recharge zones classified by their potential areal coverage as a metric for recharge suitability,namely low,medium and high suitability,occupying areas of 8625 km2(30.06%),9082 km2(31.65%),and 10,989 km~2(38.29%),respectively.Our findings have important implications for designing sustainable groundwater development and land-use plans for the coming century.

Transport of bacterial cell(E,coli)from different recharge water resources in porous media during simulated artificial groundwater recharge

Commonly used recharge water resources for artificial groundwater recharge(AGR)such as secondary effluent(SE),river water and rainfall,are all oligotrophic,with low ionic strengths and different cationic compositions.The dwelling process in recharge pond imposed physiologic stress on Escherichia coli(E.coli)cells,in all three types of investigated recharge water resources and the cultivation of E.coli under varying recharge water conditions,induced changes in cell properties.During adaptation to the recharge water environment,the zeta potential of cells became more negative,the hydrodynamic diameters,extracellular polymeric substances content and surface hydrophobicity decreased,while the cellular outer membrane protein profiles became more diverse.The mobility of cells altered in accordance with changes in these cell properties.The E.coli cells in rainfall recharge water displayed the highest mobility(least retention),followed by cells in river water and finally SE cells,which had the lowest mobility.Simulated column experiments and quantitative modeling confirmed that the cellular properties,driven by the physiologic state of cells in different recharge water matrices and the solution chemistry,exerted synergistic effects on cell transport behavior.The findings of this study contribute to an improved understanding of E.coli transport in actual AGR scenarios and prediction of spreading risk in different recharge water sources.

Removal of Organic Pollutants in Municipal Wastewater for Artificial Groundwater Recharge

In order to construct a demonstration artificial groundwater recharge system for wastewater reuse in China, three years of laboratory work has been conducted on advanced treatment technologies in combination with soil aquifer treatment of secondary effluent from sewage treatment plants. An effective and inexpensive process was selected, which uses DGB adsorption, PAC coagulation, sedimentation, sand filtration, ozone disinfection, and soil aquifer treatment. The effluent meets the recommended water quality criteria for groundwater recharge. Ozonation is effective for disinfection as well as for water quality improvement. Results showed that the total N in the SAT system remained constant thus the secondary effluent must have a low NH 3—N concentration for groundwater recharge.

Adsorption and biodegradation of three selected endocrine disrupting chemicals in river-based artificial groundwater recharge with reclaimed municipal wastewater

Endocrine disrupting chemical（EDC） pollution in river-based artificial groundwater recharge using reclaimed municipal wastewater poses a potential threat to groundwater-based drinking water supplies in Beijing, China. Lab-scale leaching column experiments simulating recharge were conducted to study the adsorption, biodegradation, and transport characteristics of three selected EDCs： 17β-estradiol（E2）, 17α-ethinylestradiol（EE2） and bisphenol A（BPA）. The three recharge columns were operated under the conditions of continual sterilization recharge（CSR）, continual recharge（CR）, and wetting and drying alternative recharge（WDAR）. The results showed that the attenuation effect of the EDCs was in the order of WDAR 〉 CR 〉 CSR system and E2 〉 EE2 〉 BPA, which followed first-order kinetics. The EDC attenuation rate constants were 0.0783, 0.0505, and 0.0479 m-1 for E2, EE2 and BPA in the CR system, respectively. The removal rates of E2, EE2, and BPA in the CR system were 98%, 96% and 92%, which mainly depended on biodegradation and were affected by water temperature.In the CR system, the concentrations of BPA, EE2, and E2 in soil were 4, 6 and 10 times higher than in the WDAR system, respectively. According to the DGGE fingerprints, the bacterial community in the bottom layer was more diverse than in the upper layer, which was related to the EDC concentrations in the water-soil system. The dominant group was found to be proteobacteria, including Betaproteobacteria and Alphaproteobacteria, suggesting that these microbes might play an important role in EDC degradation.