Reactive transport with wellbore storages in a single-well push–pull test

Abstract. Using the single-well push–pull (SWPP) test to determine the in situ biogeochemical reaction kinetics, a chase phase and a rest phase were recommended to increase the duration of reaction, besides the injection and extraction phases. In this study, we presented multi-species reactive models of the four-phase SWPP test considering the wellbore storages for both groundwater flow and solute transport and a finite aquifer hydraulic diffusivity, which were ignored in previous studies. The models of the wellbore storage for solute transport were proposed based on the mass balance, and the sensitivity analysis and uniqueness analysis were employed to investigate the assumptions used in previous studies on the parameter estimation. The results showed that ignoring it might produce great errors in the SWPP test. In the injection and chase phases, the influence of the wellbore storage increased with the decreasing aquifer hydraulic diffusivity. The peak values of the breakthrough curves (BTCs) increased with the increasing aquifer hydraulic diffusivity in the extraction phase, and the arrival time of the peak value became shorter with a greater aquifer hydraulic diffusivity. Meanwhile, the Robin condition performed well at the rest phase only when the chase concentration was zero and the solute in the injection phase was completely flushed out of the borehole into the aquifer. The Danckwerts condition was better than the Robin condition even when the chase concentration was not zero. The reaction parameters could be determined by directly best fitting the observed data when the nonlinear reactions were described by piece-wise linear functions, while such an approach might not work if one attempted to use nonlinear functions to describe such nonlinear reactions. The field application demonstrated that the new model of this study performed well in interpreting BTCs of a SWPP test.

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Reactive Transport with Wellbore Storages in a Single-Well Push-Pull Test

10.5194/hess-2018-181 ◽

2018 ◽

Author(s):

Quanrong Wang ◽

Hongbin Zhan

Keyword(s):

Solute Transport ◽

Reactive Transport ◽

Transport Processes ◽

Linear Functions ◽

Sorption Model ◽

Hydraulic Diffusivity ◽

Wellbore Storage ◽

Non Linear ◽

Single Well ◽

Robin Condition

Abstract. Using the single-well push-pull (SWPP) test to determine the in situ biogeochemical reaction kinetics, a chase phase and a rest phase were recommended to increase the duration of reaction, besides the injection and extraction phases. In this study, we presented multi-species reactive models of the four-phase SWPP test considering the wellbore storages for both groundwater flow and solute transport and a finite aquifer hydraulic diffusivity, including three isotherm-based models (Freundlich, Langmuir and linear sorption models), one-site kinetic sorption model, two-site sorption model, which were also capable of describing the biogeochemical reactive transport processes, e.g. Monod or Michaelis-Menten kinetics. The models of the wellbore storage for solute transport were derived based on the mass balance, and the results showed that ignoring it could produce great errors in the SWPP test. In the injection and chase phases, the influence of the wellbore storage increased with the decreasing aquifer hydraulic diffusivity. The peak values of the breakthrough curves (BTCs) increased with the increasing aquifer hydraulic diffusivity in the extraction phase, and the arrival time of the peak value became shorter with a greater aquifer hydraulic diffusivity. Meanwhile, the Robin condition performed well at the rest phase only when the chase concentration was zero and the solute in the injection phase was completely flushed out of the borehole into the aquifer. The Danckwerts condition was better than the Robin condition even when the chase concentration was not zero. The reaction parameters could be determined by directly best fitting the observed data when the non-linear reactions were described by piece-wise linear functions, while such an approach might not work if one attempted to use non-linear functions to describe such non-linear reactions. The field application demonstrated that the new model of this study performed well in interpreting BTCs of a SWPP test.

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New model of reactive transport in a single-well push–pull test with aquitard effect and wellbore storage

Hydrology and Earth System Sciences ◽

10.5194/hess-24-3983-2020 ◽

2020 ◽

Vol 24 (8) ◽

pp. 3983-4000

Author(s):

Quanrong Wang ◽

Junxia Wang ◽

Hongbin Zhan ◽

Wenguang Shi

Keyword(s):

Reactive Transport ◽

Molecular Diffusion ◽

Breakthrough Curves ◽

Advective Transport ◽

New Model ◽

Wellbore Storage ◽

Single Well ◽

Radial Dispersion ◽

Injection Phase ◽

Extraction Phase

Abstract. The model of single-well push–pull (SWPP) test has been widely used to investigate reactive radial dispersion in remediation or parameter estimation of in situ aquifers. Previous analytical solutions only focused on a completely isolated aquifer for the SWPP test, excluding any influence of aquitards bounding the tested aquifer, and ignored the wellbore storage of the chaser and rest phases in the SWPP test. Such simplification might be questionable in field applications when test durations are relatively long because solute transport in or out of the bounding aquitards is inevitable due to molecular diffusion and cross-formational advective transport. Here, a new SWPP model is developed in an aquifer–aquitard system with wellbore storage, and the analytical solution in the Laplace domain is derived. Four phases of the test are included: the injection phase, the chaser phase, the rest phase and the extraction phase. As the permeability of the aquitard is much smaller than the permeability of the aquifer, the flow is assumed to be perpendicular to the aquitard; thus only vertical dispersive and advective transports are considered for the aquitard. The validity of this treatment is tested against results grounded in numerical simulations. The global sensitivity analysis indicates that the results of the SWPP test are largely sensitive (i.e., influenced by) to the parameters of porosity and radial dispersion of the aquifer, whereas the influence of the aquitard on results could not be ignored. In the injection phase, the larger radial dispersivity of the aquifer could result in the smaller values of breakthrough curves (BTCs), while there are greater BTC values in the chaser and rest phases. In the extraction phase, it could lead to the smaller peak values of BTCs. The new model of this study is a generalization of several previous studies, and it performs better than previous studies ignoring the aquitard effect and wellbore storage for interpreting data of the field SWPP test reported by Yang et al. (2014).

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New Model of Reactive Transport in Single-Well Injection-Withdrawal Test with Aquitard Effect

10.5194/hess-2019-699 ◽

2020 ◽

Author(s):

Quanrong Wang ◽

Wenguang Shi ◽

Hongbin Zhan

Keyword(s):

Reactive Transport ◽

Molecular Diffusion ◽

Breakthrough Curves ◽

Advective Transport ◽

New Model ◽

Single Well ◽

Radial Dispersion ◽

Injection Phase ◽

Extraction Phase

Abstract. The model of single-well injection-withdrawal (SWIW) test has been widely used to investigate reactive radial dispersion in remediation or parameter estimation of the in situ aquifers. Previous analytical solutions only focused on a completely isolated aquifer for the SWIW test, excluding any influence of aquitards bounding the tested aquifer. This simplification might be questionable in field applications when test durations are relatively long, because solute transport in or out of the bounding aquitards is inevitable due to molecular diffusion and cross-formational advective transport. Here, a new SWIW model is developed in an aquifer-aquitard system, and the analytical solution in the Laplace domain is derived. Four phases of the test are included: the injection phase, the chaser phase, the rest phase and the extraction phase. The Green's function method is employed for the solution in the extraction phase. As the permeability of aquitard is much smaller than the permeability of the aquifer, the flow is assumed to be perpendicular to the aquitard, thus only vertical dispersive and advective transports are considered for aquitard. The validity of this treatment is tested by a numerical solution. The sensitivity analysis demonstrates that the influence of vertical flow velocity and porosity in the aquitards, and radial dispersion of the aquifer is more sensitive to the SWIW test than other parameters. In the injection phase, the larger radial dispersivity of the aquifer could result in the smaller values of breakthrough curves (BTCs), while greater values of BTCs of the chaser and rest phases. In the extraction phase, it could lead to the smaller peak values of BTCs. The new model of this study performs better than previous studies excluding the aquitard effect for interpreting data of the field SWIW test.

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Solute transport analysis of bromide, uranin and LiCl using breakthrough curves from aquifer sediment

Journal of Contaminant Hydrology ◽

10.1016/s0169-7722(99)00033-9 ◽

1999 ◽

Vol 39 (1-2) ◽

pp. 7-34 ◽

Cited By ~ 16

Author(s):

H Vereecken ◽

U Jaekel ◽

O Esser ◽

O Nitzsche

Keyword(s):

Solute Transport ◽

Breakthrough Curves ◽

Transport Analysis

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VALIDATION OF SOLUTE TRANSPORT EVALUATING METHOD WITH AMBIENT GROUNDWATER FLOW FOR SINGLE-WELL INJECTION-WITHDRAWAL TESTS

Journal of Japan Society of Civil Engineers Ser C (Geosphere Engineering) ◽

10.2208/jscejge.72.224 ◽

2016 ◽

Vol 72 (3) ◽

pp. 224-238

Author(s):

Shintaro NOHARA ◽

Takuma HASEGAWA ◽

Yasuharu TANAKA

Keyword(s):

Groundwater Flow ◽

Solute Transport ◽

Single Well ◽

Ambient Groundwater ◽

Evaluating Method

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Direct characterization of solute transport in unsaturated porous media using fast X-ray synchrotron microtomography

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2011716117 ◽

2020 ◽

Vol 117 (38) ◽

pp. 23443-23449 ◽

Cited By ~ 3

Author(s):

Sharul Hasan ◽

Vahid Niasar ◽

Nikolaos K. Karadimitriou ◽

Jose R. A. Godinho ◽

Nghia T. Vo ◽

...

Keyword(s):

Solute Transport ◽

High Speed ◽

Three Dimensional ◽

Concentration Field ◽

Solute Concentration ◽

Breakthrough Curves ◽

Pore Scale ◽

X Ray ◽

Long Tails ◽

Computed Microtomography

Solute transport in unsaturated porous materials is a complex process, which exhibits some distinct features differentiating it from transport under saturated conditions. These features emerge mostly due to the different transport time scales at different regions of the flow network, which can be classified into flowing and stagnant regions, predominantly controlled by advection and diffusion, respectively. Under unsaturated conditions, the solute breakthrough curves show early arrivals and very long tails, and this type of transport is usually referred to as non-Fickian. This study directly characterizes transport through an unsaturated porous medium in three spatial dimensions at the resolution of 3.25 μm and the time resolution of 6 s. Using advanced high-speed, high-spatial resolution, synchrotron-based X-ray computed microtomography (sCT) we obtained detailed information on solute transport through a glass bead packing at different saturations. A large experimental dataset (>50 TB) was produced, while imaging the evolution of the solute concentration with time at any given point within the field of view. We show that the fluids’ topology has a critical signature on the non-Fickian transport, which yet needs to be included in the Darcy-scale solute transport models. The three-dimensional (3D) results show that the fully mixing assumption at the pore scale is not valid, and even after injection of several pore volumes the concentration field at the pore scale is not uniform. Additionally, results demonstrate that dispersivity is changing with saturation, being twofold larger at the saturation of 0.52 compared to that at the fully saturated domain.

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Comparative analyses of alternative breakthrough curves from cumulative mass column testing of soil–bentonite backfills

Canadian Geotechnical Journal ◽

10.1139/cgj-2019-0468 ◽

2020 ◽

Vol 57 (8) ◽

pp. 1197-1214 ◽

Cited By ~ 1

Author(s):

Charles D. Shackelford ◽

Catherine S. Hong

Keyword(s):

Steady State ◽

Solute Transport ◽

Breakthrough Curves ◽

Retardation Factor ◽

Dimensionless Time ◽

Mass Ratio ◽

Column Tests ◽

Cutoff Walls ◽

Cumulative Mass ◽

Linear Regressions

The results of eight cumulative mass column tests were analyzed via several different methods to evaluate the dispersion coefficient, D, and the retardation factor, Rd, governing the migration of chloride (Cl−), potassium (K), and zinc (Zn) through soil–bentonite backfills for vertical cutoff walls. Regression of the measured relative (effluent) concentration (RC) breakthrough curves (BTCs) resulted in relatively accurate determinations of Rd, but relatively inaccurate determinations of D for all three solutes. Values of Rd based on dimensionless time, T, corresponding to an RC of 0.5 were underestimated for all three solutes due to the significance of diffusion on solute transport. With a few exceptions, Rd for K and Zn based on analyses of the steady-state portions of measured cumulative mass ratio (CMR) BTCs and T – CMR BTCs were relatively accurate, whereas analysis of measured T – CMR BTCs was more accurate for determining Rd of Cl−. Overall, there is no advantage to analyzing the results of cumulative mass column tests in the form of RC BTCs, whereas the CMR and T – CMR BTCs offer the advantage of determining Rd based on simple linear regressions of the steady-state portions of the BTCs, i.e., provided steady-state solute transport has been established.

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Review of Physical and Chemical Properties of Perfluorooctanyl sulphonate (PFOS) with Respect to its Potential Contamination on the Environment

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.518-523.2183 ◽

2012 ◽

Vol 518-523 ◽

pp. 2183-2191 ◽

Cited By ~ 5

Author(s):

Sheng Zhang ◽

David N Lerner

Keyword(s):

Chemical Properties ◽

Hydrocarbon Fuel ◽

The United States ◽

Breakthrough Curves ◽

Film Forming ◽

Perfluorinated Surfactants ◽

Blood Banks ◽

Single Well ◽

Physical And Chemical ◽

By Products

Perfluorinated surfactants have emerged as priority environmental contaminants due to their detection in environmental and biological matrices as well as concerns regarding their persistence and toxicity. They have been found in groundwater, particularly at sites used for training firefighters. They do not biodegrade easily in groundwater, and are not retarded during transport. The most common chemical is Perfluorooctanyl Sulphonate (PFOS), which is mainly used in aqueous film forming foam (AFFF) to extinguish hydrocarbon-fuel fires. It is also used in many herbicide and insecticide formulations, cosmetics, greases and lubricants, paints, polishes, and adhesives. PFOS and related fluoro-organic chemicals have been used since the 1950s. A quantity of fluorosurfactants and related products are still in use all over the world. Intensive studies over the last few years discovered that PFOS and certain by-products were both ubiquitous in the environment and highly persistent. PFOS does not biodegrade in the environment and very limited degradation has been observed in wastewater treatment. The breakthrough curves of a single-well push-pull test indicated that there was no retardation for PFOS as well. It was detected in part-per-billion levels in blood samples obtained from blood banks in the United States, Japan, Europe, and China. There have been more and more reports on the accumulation and effect of PFOS in wild animals’ liver, serum and muscle as well. This suggests that PFOS can bioaccumulate to higher levels of the food chain.

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