scholarly journals Semi-analytical 3D solution for assessing radial collector well pumping impacts on groundwater–surface water interaction

2017 ◽  
Vol 49 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Ali A. Ameli ◽  
James R. Craig
Keyword(s):  
Surface Water ◽  
Transport Model ◽  
Water Remediation ◽  
Pumping Rate ◽  
River Bank ◽  
Meandering River ◽  
Unconfined Aquifers ◽  
Well Location ◽  
Head Protection ◽  
Radial Collector Well

Abstract We present a new semi-analytical flow and transport model for the simulation of 3D steady-state flow and particle movement between groundwater, a surface water body and a radial collector well in geometrically complex unconfined aquifers. This precise and grid-free Series Solution-analytic element method approach handles the irregular configurations of radial wells more efficiently than grid-based methods. This method is then used to explore how pumping well location and river shape interact and together influence (1) transit time distribution (TTD) of captured water in a radial collector well and TTD of groundwater discharged into the river and (2) the percentage of well waters captured from different sources. Results show that meandering river shape plays a significant role in controlling the aforementioned metrics and that increasing the pumping rate has different consequences in different situations. This approach can also inform the design of water remediation and groundwater protection systems (e.g., river bank filtration and well head protection area).

scholarly journals Modeling of sorption and degradation of selected pharmaceuticals: Case study of Belgrade groundwater source

2017 ◽  
pp. 47-59 ◽  
Author(s):  
Milan Dimkic ◽  
Srdjan Kovacevic ◽  
Milenko Pusic ◽  
Milan Dotlic
Keyword(s):  
Surface Water ◽  
Half Life ◽  
Transport Model ◽  
Sorption Isotherms ◽  
Tracer Experiment ◽  
Average Concentration ◽  
Sava River ◽  
Groundwater Source ◽  
Radial Collector Well ◽  
The Sava River

The application of a mathematical model that analyzes the transport of selected pharmaceuticals from the Sava River to a corresponding radial collector well at Belgrade?s groundwater source is assessed. The occurrence of the selected pharmaceuticals in surface water and the corresponding well was monitored from 2009 to 2015. The pharmaceuticals selected for the present study are carbamazepine, trimethoprim, and metamizole metabolites 4-AAA and 4-FAA. Transport is analyzed based on experimental data (sorption isotherms) and a field tracer experiment that includes injection of the selected pharmaceuticals. The analysis shows that sorption of carbamazepine is relatively low and that this pharmaceutical does not degrade under the studied conditions, so it is not possible to accurately determine the degradation half-life. Trimethoprim is detected in the Sava River with an average concentration 8.5 ng/L, but there is no positive detection in well Rb-16. The average concentration of 4-AAA in the surface water is 34 ng/L and of 4-FAA 13 ng/L. The average concentrations of 4-FAAand 4-AAA in the groundwater are in the range from 1 and 1.85 ng/L. The objective of the research is to use an existing hydrogeologic model and apply a transport model to determine the minimum degradation half-life of the investigated pharmaceuticals.

scholarly journals Seasonal dynamics modifies fate of oxygen, nitrate, and organic micropollutants during bank filtration — temperature-dependent reactive transport modeling of field data

2020 ◽  
Author(s):  
Isolde S. Barkow ◽  
Sascha E. Oswald ◽  
Hermann-Josef Lensing ◽  
Matthias Munz
Keyword(s):  
Surface Water ◽  
Reactive Transport ◽  
Oxygen Supply ◽  
Transport Model ◽  
Water Levels ◽  
Spatial Behavior ◽  
Seasonal Temperature ◽  
Bank Filtration ◽  
Organic Micropollutants ◽  
Degradation Rates

Abstract Bank filtration is considered to improve water quality through microbially mediated degradation of pollutants and is suitable for waterworks to increase their production. In particular, aquifer temperatures and oxygen supply have a great impact on many microbial processes. To investigate the temporal and spatial behavior of selected organic micropollutants during bank filtration in dependence of relevant biogeochemical conditions, we have set up a 2D reactive transport model using MODFLOW and PHT3D under the user interface ORTI3D. The considered 160-m-long transect ranges from the surface water to a groundwater extraction well of the adjacent waterworks. For this purpose, water levels, temperatures, and chemical parameters were regularly measured in the surface water and groundwater observation wells over one and a half years. To simulate the effect of seasonal temperature variations on microbial mediated degradation, we applied an empirical temperature factor, which yields a strong reduction of the degradation rate at groundwater temperatures below 11 °C. Except for acesulfame, the considered organic micropollutants are substantially degraded along their subsurface flow paths with maximum degradation rates in the range of 10−6 mol L−1 s−1. Preferential biodegradation of phenazone, diclofenac, and valsartan was found under oxic conditions, whereas carbamazepine and sulfamethoxazole were degraded under anoxic conditions. This study highlights the influence of seasonal variations in oxygen supply and temperature on the fate of organic micropollutants in surface water infiltrating into an aquifer.

scholarly journals Synthesis of CNS, ZnO/CNS and ZnCnO4/CNS composites from patchouli biomass by using microwave for remediation of pesticide contaminated surface water in paddy field

2021 ◽  
Vol 930 (1) ◽  
pp. 012020
Author(s):  
T Setianingsih ◽  
D Purwonugroho ◽  
YP Prananto
Keyword(s):  
Surface Water ◽  
Paddy Field ◽  
Water Remediation ◽  
Turbostratic Carbon ◽  
Carbon Structures ◽  
Ftir Spectrometry ◽  
Dispersion Test ◽  
Degradation Test ◽  
Carbamate Pesticide ◽  
Potential Precursor

Abstract Patchouli biomass is a potential precursor for CNS synthesis. In this research, the patchouli was pyrolyzed using the microwave. The purpose of this research is to study the effect of microwave energy and activator toward physicochemistry of CNS and composite (ZnO/CNS) and application of ZnCr2O4/CNS for the pesticide polluted surface water remediation in paddy field. In the process, the biomass was pyrolyzed at four and 8W with and without the ZnCl2 activator. The products were blended and evaporated to obtain CNS and ZnO/CNS. The products were characterized using FTIR spectrometry, XRD, and dispersion test. The composites were used to synthesize ZnCr2O4/CNS at 600W in the microwave. The composites were used for buthylphenylmethyl carbamate pesticide degradation test (BPMC) for 48 h with H2O2 oxidation. The FTIR spectra indicated better carbonization for products taken using an activator at both microwave energies. The X-ray diffractograms showed the turbostratic structure of carbon obtained at 4W pyrolysis (with activator), meanwhile 8W pyrolysis (without activator). ZnO and turbostratic carbon structures were shown by the product of 8W pyrolisis with activator. The calcined composite indicated ZnCr2O4/CNS. The degradation test showed that ZnCr2O4/CNS(8W) catalyst decreased the BMPC concentration almost three times that of the composite (4W).

scholarly journals Discharge estimation in a backwater affected meandering river

2011 ◽  
Vol 8 (2) ◽  
pp. 2667-2697 ◽  
Author(s):  
H. Hidayat ◽  
B. Vermeulen ◽  
M. G. Sassi ◽  
P. J. J. F. Torfs ◽  
A. J. F. Hoitink
Keyword(s):  
River Flow ◽  
Discharge Rate ◽  
River Mouth ◽  
Level Gauge ◽  
River Bank ◽  
Surface Level ◽  
Meandering River ◽  
Discharge Variation ◽  
Adcp Data ◽  
Discharge Estimation

Abstract. Variable effects of backwaters complicate the development of rating curves at hydrometric measurement stations. In areas influenced by backwater, single-parameter rating curve techniques are often inapplicable. To overcome this, several authors have advocated the use of an additional downstream level gauge to estimate the longitudinal surface level gradient, but this is cumbersome in a lowland meandering river with considerable transverse surface level gradients. Recent developments allow river flow to be continuously monitored through velocity measurements with an acoustic Doppler current profiler (H-ADCP), deployed horizontally at a river bank. This approach was adopted to obtain continuous discharge estimates at a cross-section in the River Mahakam at a station located about 300 km upstream of the river mouth in the Mahakam delta. The discharge station represents an area influenced by variable backwater effects from lakes, tributaries and floodplain ponds, and by tides. We applied both the standard index velocity method and a recently developed methodology to obtain a continuous time-series of discharge from the H-ADCP data. Measurements with a boat-mounted ADCP were used for calibration and validation of the model to translate H-ADCP velocity to discharge. As a comparison with conventional discharge estimation techniques, a stage-discharge relation using Jones formula was developed. The discharge rate at the station exceeded 3300 m3 s−1. Discharge series from a traditional stage-discharge relation did not capture the overall discharge dynamics, as inferred from H-ADCP data. For a specific river stage, the discharge range could be as high as 2000 m3 s−1, which is far beyond what could be explained from kinematic wave dynamics. Backwater effects from lakes were shown to be significant, whereas the river-tide interaction may impact discharge variation in the fortnightly frequency band. Fortnightly tides cannot easily be isolated from river discharge variation, which features similar periodicities.

scholarly journals Groundwater and River Interaction Impact to Aquifer System in Saigon River Basin, Vietnam

2020 ◽  
Vol 24 (5) ◽  
pp. 15-24
Author(s):  
Tran Thanh Long ◽  
Sucharit Koontanakulvong
Keyword(s):  
Surface Water ◽  
River Basin ◽  
Water Demand ◽  
Developing Economies ◽  
High Water ◽  
Groundwater Pumping ◽  
Pumping Rate ◽  
Aquifer System ◽  
Groundwater Reserves ◽  
The Impact

Since the 1990s, under the pressure of socio-economic growth in the Ho Chi Minh City and nearby provinces, the heavy-extraction of groundwater of this area has dramatically increased to meet high water demand for domestic and industrial purposes. Although the groundwater – Saigon River interaction significantly contributes to groundwater reserves, researchers have been less attentive to fully describe and understand the river recharge. This study attempts to explore the impact of groundwater-river interaction to aquifer system due to pumping increase via field seepage and (O18, H2) isotopic measurements in the Saigon River Basin, South East of Vietnam. The analysis showed that river bed conductance at 0 km, 30 km, 60 km, 80 km, and 120 km were 4.5 m2/day/m, 4.2 m2/day/m, 2.5 m2/day/m, 1.7 m2/day/m, and 0.25 m2/day/m respectively. The riverbed conductance relies on the sand percentage of sediment. The composition δO18 in groundwater, river, and precipitation indicates that river recharge to groundwater exists mainly in the lower part of the basin. In contrast to downstream, the composition of δO18 was signified that the river primarily gains water from groundwater upstream. Under pressure of developing economies, the groundwater pumping in the Saigon river basin increased from 175,000 m3/day in 1995 to 880,000 m3/day in 2017. As a consequence of the increased pumping rate, the groundwater discharge to the river decreases from 1.6 to 0.7 times of groundwater pumping in upstream, while the amount of Saigon river recharge increases by 33% to 50% of the total groundwater pumping downstream. Under the exceedance pumping rate, the aquifers in the Saigon River Basin release less water to the Saigon river and it tends to gain more water through the river - groundwater interaction process. Therefore, groundwater management in downstream aquifers needs better joint planning with surface water development plans, particularly for surface water supply utilities which still struggle to satisfy the water demand of the development plan.

scholarly journals Optimized Pumping Strategy for Reducing the Spatial Extent of Saltwater Intrusion along the Coast of Wadi Ham, UAE

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1503 ◽  
Author(s):  
Modou A. Sowe ◽  
Sadhasivam Sathish ◽  
Nicolas Greggio ◽  
Mohamed M. Mohamed
Keyword(s):  
Saltwater Intrusion ◽  
Transport Model ◽  
Saline Water ◽  
Anthropogenic Impacts ◽  
Optimum Number ◽  
Constant Number ◽  
Pumping Rate ◽  
Discharge Rates ◽  
Pumping Wells ◽  
Pumping Rates

Many coastal aquifers are facing severe anthropogenic impacts such as urbanization, industrialization and agricultural activities are resulting in a saltwater intrusion. This establishes the need for a sustainable groundwater management strategy aimed to overcome the situation. Pumping of brackish/saline water to mitigate saltwater intrusion is a major potential approach to effectively control saltwater intrusion. However, this method has many challenges including selection of appropriate discharge rates under an optimum number of pumping wells and at specified wells distance from the shoreline. Hence, this study developed a Finite Element Flow and solute transport model (FEFLOW) to simulate three scenarios to assess the most appropriate pumping rates, number of wells and optimum well locations from the shoreline. These parameters were assessed and evaluated with respect to the change in groundwater saline concentration at different distance from the coastline. The 15,000 mg L−1 isosalinity contour line was used as a linear threshold to assess the progression of saltwater intrusion along three major locations in the aquifer. Scenario One was simulated with a constant number of wells and rate of pumping. Shifting of pumping wells to several distances from the shoreline was conducted. Scenario Two assessed the most appropriate number of pumping wells under constant pumping rates and distances from the shoreline and in scenario 3, the optimum pumping rates under a constant number of wells and distance from the shoreline were simulated. The results showed that the pumping of brackish/saline water from a distance of 1500 m from the shoreline using 16 pumping wells at a total pumping rate of 8000 m3 d−1 is the most effective solution in contrasting the saltwater intrusion in the Wadi Ham coastal aquifer.

Are in-stream transport and hyporheic exchange parameters identifiable from tracer test data?

2020 ◽  
Author(s):  
Andrea Bottacin-Busolin
Keyword(s):  
Surface Water ◽  
Water Column ◽  
Transport Model ◽  
Transport Processes ◽  
Hyporheic Exchange ◽  
Model Parameters ◽  
Cross Sectional ◽  
One Dimensional ◽  
Stream Transport ◽  
Exchange Parameters

<p>Inverse modeling approaches based on tracer data are often used to characterize transport processes in streams and rivers. This generally involves the calibration of a one-dimensional transport model using concentrations measured in the surface water at one or multiple locations along a stream reach. A major concern is whether the calibrated model parameters are representative of the physical transport processes occurring in the water column and the underlying sediment bed. This study looks at the identifiability of the parameters of a physically based one-dimensional stream transport model that represents hyporheic exchange as a vertically attenuated mixing process in accordance with recent experimental evidence. It is shown that, if the average flow velocity and hydraulic radius are not predetermined, there are infinite sets of parameter values that generate the same space-time concentration distributions in the water column. The result implies that in-stream transport and hyporheic exchange parameters cannot be determined from sole measurements of solute breakthrough curves in the surface water unless stream discharge and average cross-sectional geometry can be independently estimated.</p>

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