Special Issue "Contaminant Transport and Fate"

A special issue of Water (ISSN 2073-4441). This special issue belongs to the section "Hydrology and Hydrogeology".

Deadline for manuscript submissions: closed (31 January 2021).

Special Issue Editors

Prof. Dr. Thomas Boving
E-Mail Website
Guest Editor
Department of Geosciences & Department of Civil and Environmental Engineering, University of Rhode Island, Kingston, RI 02881, USA
Interests: Environmental Hydrogeology, Remediation, Water Resources, Riverbank Filtration
Special Issues and Collections in MDPI journals
Prof. Dr. William J. Blanford
E-Mail Website
Guest Editor
Queens College, City University of New York, Flushing, United States
Interests: Groundwater pollution; remediation; cyclodextrin; riverbank filtration; chemodynamics

Special Issue Information

Dear Colleagues,

This Special Issue seeks to highlight current contaminant transport and fate challenges. Contaminant transport in porous media is controlled by advection, dispersion, retardation, phase transfers, and transformation processes facilitated by biological, chemical, or physical agents. Contaminant mass transfer processes that redistribute solutes through subsurface phases or through engineered systems are of particular interest to remediation engineers, scientists, policy-makers, and the public.

Laboratory and field-scale studies are conducted to study these processes. The incorporation of contaminant transport and mass transfer processes into computational or numerical models enables scientists and site managers to develop conceptual frameworks, which are essential for efficacious management of polluted sites. Innovative technologies that accelerate contaminant extraction, destruction, seclusion, or management either in situ or ex situ can be used to deal with environmental pollution problems. The emergence of previously unknown or undetectable toxic chemicals amplifies the need for innovative remediation technologies and approaches. Many emerging contaminants are “site reopeners” because locations thought to be successfully cleaned up have to be re-examined. The detection of emerging contaminants may be improved by advanced diagnostic tools or the implementation of enhanced amendment delivery methods. Sustainable remediation technologies are sought to address the high cost and risks to human health of environments associated with these sites.

Prof. Dr. Thomas Boving
Prof. Dr. William J. Blanford
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Water is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2000 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Contaminant Fate and Transport
  • Environmental Hydrogeology
  • Innovative Remediation Technology
  • Sustainable and Green Remediation Technologies
  • Emerging Contaminants
  • Mass Transfer Processes
  • Enhanced Amendment Delivery Methods
  • Modeling
  • Site Reopeners
  • Advanced Diagnostic Tools
  • Conceptional Site Models

Published Papers (8 papers)

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Editorial

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Editorial
Contaminant Transport and Fate
Water 2021, 13(9), 1195; https://doi.org/10.3390/w13091195 - 26 Apr 2021
Viewed by 359
Abstract
This Special Issue highlights many of the predominant contaminant transport and fate processes that redistribute solutes through natural and engineered surface and subsurface environments [...] Full article
(This article belongs to the Special Issue Contaminant Transport and Fate)

Research

Jump to: Editorial

Article
Using Concentration–Discharge Relationships to Identify Influences on Surface and Subsurface Water Chemistry along a Watershed Urbanization Gradient
Water 2021, 13(5), 662; https://doi.org/10.3390/w13050662 - 28 Feb 2021
Cited by 1 | Viewed by 717
Abstract
Urban development within watersheds impacts the hydrology and water quality of streams, but changes to groundwater–surface water interactions in this “urban stream syndrome” are not yet well understood. This study focused on three stream systems in a northern Virginia (USA) protected area with [...] Read more.
Urban development within watersheds impacts the hydrology and water quality of streams, but changes to groundwater–surface water interactions in this “urban stream syndrome” are not yet well understood. This study focused on three stream systems in a northern Virginia (USA) protected area with 14.2, 31.7, and 66.1% developed land in their watersheds. Surface water was sampled weekly for nutrients, dissolved metals, sulfate, ancillary water quality parameters, and discharge over two non-consecutive years with the hyporheic zone sampled during the second year. Concentration–discharge relationships revealed largely chemostatic behavior in surface water solutes in the least urbanized stream, while in the two more urbanized streams, these relationships tended to have significant positive and negative slopes, indicating diverse delivery pathways depending on the constituent. In the least urbanized stream, linear regressions between discharge and solute concentrations in hyporheic water had exclusively negative slopes, indicating source-limited delivery, while the other two urbanized streams maintained largely chemostatic behavior. Average specific conductance and nitrate + nitrite concentrations in stream surface water reflected an urbanization gradient, while sulfate, Ca, K and Sr concentrations suggested a threshold effect: the stream with a mostly forested watershed had the lowest concentrations, while the other two were higher and similar. Specific conductance indicated salinization of both surface and groundwater at the two more urban streams, possibly threatening aquatic organisms. Metal concentrations in surface and subsurface water were often positively correlated with specific conductance and negatively correlated with pH, suggesting that they may originate from road salt and/or be mobilized by acid precipitation. These results indicate the importance of monitoring both baseflow and stormflow as pathways for pollution. Full article
(This article belongs to the Special Issue Contaminant Transport and Fate)
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Article
Evaluating Potential for Groundwater Contamination from Surface Spills Associated with Unconventional Oil and Gas Production: Methodology and Application to the South Platte Alluvial Aquifer
Water 2021, 13(3), 353; https://doi.org/10.3390/w13030353 - 30 Jan 2021
Cited by 1 | Viewed by 478
Abstract
Surface spills occur frequently during unconventional oil and gas production operations and have the potential to impact groundwater quality. A screening-level analysis using contaminant fate and transport simulations was performed to: (1) evaluate whether hypothetical (yet realistic) spills of aqueous produced fluids pose [...] Read more.
Surface spills occur frequently during unconventional oil and gas production operations and have the potential to impact groundwater quality. A screening-level analysis using contaminant fate and transport simulations was performed to: (1) evaluate whether hypothetical (yet realistic) spills of aqueous produced fluids pose risks to groundwater quality in the South Platte Aquifer, (2) identify the key hydrologic and transport factors that determine these risks, and (3) develop a screening-level methodology that could be applied for other sites and pollutants. This assessment considered a range of representative hydrologic conditions and transport behavior for benzene, a regulated pollutant in production fluids. Realistic spill volumes and areas were determined using publicly available data collected by Colorado’s regulatory agency. Risk of groundwater pollution was based on predicted benzene concentrations at the groundwater table. Results suggest that the risk of groundwater contamination from benzene in a produced water spill was relatively low in the South Platte Aquifer. Spill size was the dominant factor influencing whether a contaminant reached the water table. Only statistically larger spills (volume per surface area ≥12.0 cm) posed a clear risk. Storm events following a spill were generally required to transport typical (median)-sized spills (0.38 cm volume per surface area) to the water table; typical spills only posed risk if a 500 or 100 year storm (followed by little degradation or sorption) occurred right after the spill. This methodology could be applied to evaluate spills occurring over other aquifers. Full article
(This article belongs to the Special Issue Contaminant Transport and Fate)
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Article
Multi-Gene Genetic Programming Regression Model for Prediction of Transient Storage Model Parameters in Natural Rivers
Water 2021, 13(1), 76; https://doi.org/10.3390/w13010076 - 31 Dec 2020
Cited by 2 | Viewed by 659
Abstract
A Transient Storage Model (TSM), which considers the storage exchange process that induces an abnormal mixing phenomenon, has been widely used to analyze solute transport in natural rivers. The primary step in applying TSM is a calibration of four key parameters: flow zone [...] Read more.
A Transient Storage Model (TSM), which considers the storage exchange process that induces an abnormal mixing phenomenon, has been widely used to analyze solute transport in natural rivers. The primary step in applying TSM is a calibration of four key parameters: flow zone dispersion coefficient (Kf), main flow zone area (Af), storage zone area (As), and storage exchange rate (α); by fitting the measured Breakthrough Curves (BTCs). In this study, to overcome the costly tracer tests necessary for parameter calibration, two dimensionless empirical models were derived to estimate TSM parameters, using multi-gene genetic programming (MGGP) and principal components regression (PCR). A total of 128 datasets with complete variables from 14 published papers were chosen from an extensive meta-analysis and were applied to derivations. The performance comparison revealed that the MGGP-based equations yielded superior prediction results. According to TSM analysis of field experiment data from Cheongmi Creek, South Korea, although all assessed empirical equations produced acceptable BTCs, the MGGP model was superior to the other models in parameter values. The predicted BTCs obtained by the empirical models in some highly complicated reaches were biased due to misprediction of Af. Sensitivity analyses of MGGP models showed that the sinuosity is the most influential factor in Kf, while Af, As, and α, are more sensitive to U/U*. This study proves that the MGGP-based model can be used for economic TSM analysis, thus providing an alternative option to direct calibration and the inverse modeling initial parameters. Full article
(This article belongs to the Special Issue Contaminant Transport and Fate)
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Article
Comparison of Manganese Dioxide and Permanganate as Amendments with Persulfate for Aqueous 1,4-Dioxane Oxidation
Water 2020, 12(11), 3061; https://doi.org/10.3390/w12113061 - 01 Nov 2020
Cited by 1 | Viewed by 840
Abstract
Persulfate (PS) is widely used to degrade emerging organic contaminants in groundwater and soil systems, and various PS activation methods (e.g., energy or chemical inputs) have been considered to increase oxidation strength. This study investigates PS activation through manganese amendment in the form [...] Read more.
Persulfate (PS) is widely used to degrade emerging organic contaminants in groundwater and soil systems, and various PS activation methods (e.g., energy or chemical inputs) have been considered to increase oxidation strength. This study investigates PS activation through manganese amendment in the form of potassium permanganate (KMnO4) and manganese dioxide (MnO2) to subsequently degrade the emerging and recalcitrant groundwater contaminant 1,4-dioxane (1,4-D). The activation of PS by MnO2 was confirmed by radical trap and by product formation. The degradation kinetics of 1,4-D by PS was also compared with varying amendments of KMnO4 and MnO2. The results showed that MnO2 activated PS, which increased the degradation rate constant of 1,4-D. KMnO4 activation of PS was not observed even though the binary oxidant mixture did enhance the degradation of 1,4-D. These results have implications for applying in situ chemical oxidation in subsurface systems, especially for conditions wherein manganese exists naturally in groundwater or aquifer minerals to support possible PS activation. Full article
(This article belongs to the Special Issue Contaminant Transport and Fate)
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Article
A Modified HYDRUS Model for Simulating PFAS Transport in the Vadose Zone
Water 2020, 12(10), 2758; https://doi.org/10.3390/w12102758 - 03 Oct 2020
Cited by 7 | Viewed by 1009
Abstract
The HYDRUS unsaturated flow and transport model was modified to simulate the effects of non-linear air-water interfacial (AWI) adsorption, solution surface tension-induced flow, and variable solution viscosity on the unsaturated transport of per- and polyfluoroalkyl substances (PFAS) within the vadose zone. These modifications [...] Read more.
The HYDRUS unsaturated flow and transport model was modified to simulate the effects of non-linear air-water interfacial (AWI) adsorption, solution surface tension-induced flow, and variable solution viscosity on the unsaturated transport of per- and polyfluoroalkyl substances (PFAS) within the vadose zone. These modifications were made and completed between March 2019 and May 2019, and were implemented into both the one-dimensional (1D) and two-dimensional (2D) versions of HYDRUS. Herein, the model modifications are described and validated against the available literature-derived PFAS transport data (i.e., 1D experimental column transport data). The results of both 1D and 2D example simulations are presented to highlight the function and utility of the model to capture the dynamic and transient nature of the temporally and spatially variable interfacial area of the AWI (Aaw) as it changes with soil moisture content (Θw) and how it affects PFAS unsaturated transport. Specifically, the simulated examples show that while AWI adsorption of PFAS can be a significant source of retention within the vadose zone, it is not always the dominant source of retention. The contribution of solid-phase sorption can be considerable in many PFAS-contaminated vadose zones. How the selection of an appropriate Aaw(Θw) function can impact PFAS transport and how both mechanisms contribute to PFAS mass flux to an underlying groundwater source is also demonstrated. Finally, the effects of soil textural heterogeneities on PFAS unsaturated transport are demonstrated in the results of both 1D and 2D example simulations. Full article
(This article belongs to the Special Issue Contaminant Transport and Fate)
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Article
Nonlinear Autoregressive Neural Networks to Predict Hydraulic Fracturing Fluid Leakage into Shallow Groundwater
Water 2020, 12(3), 841; https://doi.org/10.3390/w12030841 - 17 Mar 2020
Cited by 11 | Viewed by 1005
Abstract
Hydraulic fracturing of horizontal wells is an essential technology for the exploitation of unconventional resources, but led to environmental concerns. Fracturing fluid upward migration from deep gas reservoirs along abandoned wells may pose contamination threats to shallow groundwater. This study describes the novel [...] Read more.
Hydraulic fracturing of horizontal wells is an essential technology for the exploitation of unconventional resources, but led to environmental concerns. Fracturing fluid upward migration from deep gas reservoirs along abandoned wells may pose contamination threats to shallow groundwater. This study describes the novel application of a nonlinear autoregressive (NAR) neural network to estimate fracturing fluid flow rate to shallow aquifers in the presence of an abandoned well. The NAR network is trained using the Levenberg–Marquardt (LM) and Bayesian Regularization (BR) algorithms and the results were compared to identify the optimal network architecture. For NAR-LM model, the coefficient of determination (R2) between measured and predicted values is 0.923 and the mean squared error (MSE) is 4.2 × 10−4, and the values of R2 = 0.944 and MSE = 2.4 × 10−4 were obtained for the NAR-BR model. The results indicate the robustness and compatibility of NAR-LM and NAR-BR models in predicting fracturing fluid flow rate to shallow aquifers. This study shows that NAR neural networks can be useful and hold considerable potential for assessing the groundwater impacts of unconventional gas development. Full article
(This article belongs to the Special Issue Contaminant Transport and Fate)
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Article
N-Nitrosodimethylamine Formation from Treatment of Seasonally and Spatially Varying Source Water
Water 2019, 11(10), 2019; https://doi.org/10.3390/w11102019 - 28 Sep 2019
Cited by 2 | Viewed by 1011
Abstract
N-nitrosodimethylamine (NDMA) is a disinfection by-product (DBP) that has been classified as a probable human carcinogen in multiple risk assessments. NDMA presence in drinking water is widespread and dependent on source water, disinfectant type, precursors, and water treatment strategies. The objectives of this [...] Read more.
N-nitrosodimethylamine (NDMA) is a disinfection by-product (DBP) that has been classified as a probable human carcinogen in multiple risk assessments. NDMA presence in drinking water is widespread and dependent on source water, disinfectant type, precursors, and water treatment strategies. The objectives of this study were to investigate NDMA formation potential in a modeled monochloramine water treatment plant (WTP) fed by seasonally and spatially varying source water; and to optimize DBP precursor removal by combining conventional and additional treatment techniques. After NDMA analysis, it was found that NDMA formation was significantly dependent on source water type and monochloramine contact time (CT); e.g., at 24 h CT, Cork Brook produced 12.2 ng/L NDMA and Bailey Brook produced 4.2 ng/L NDMA, compared with 72 h CT, Cork Brook produced 4.1 ng/L NDMA and Bailey Brook produced 3.4 ng/L NDMA. No correlations were found between traditional DBP precursors such as total organic carbon and total nitrogen, and the formation of NDMA. The laboratory bench-top treatment system was highly effective at removing traditional DBP precursors, highlighting the need for WTPs to alter their current treatment methods to best accommodate the complex system of DBP control. Full article
(This article belongs to the Special Issue Contaminant Transport and Fate)
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