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Journal of Contaminant Hydrology

Stephane K Ngueleu, Fereidoun Rezanezhad, Riyadh I Al-Raoush, Philippe Van Cappellen
Considerable activities from the oil and natural gas sector have risen some concerns about the pollution of soil and groundwater by petroleum hydrocarbons (PHCs) in (semi)-arid coastal regions. The understanding of the fate and transport of PHCs in these regions is therefore necessary to develop strategies for remediation. To quantify the sorption rates of PHCs in (semi)-arid coastal soil environments, we conducted a series of controlled-laboratory batch experiments under variable temperature and salinity conditions...
November 3, 2018: Journal of Contaminant Hydrology
Ya Wu, Zhaohui Luo, Wei Luo, Teng Ma, Yanxin Wang
Karst water is an important resource for drinking water supply. To determine the impacts of urbanization on karst water quality, we performed a case study in the rapidly urbanized Guiyang-Anshun region, Guizhou province, southwestern China. We interpret data from regional reconnaissance and long-term monitoring related to major ion chemistry, stable isotopes (Sr, C, S (for SO4 2- ), and N and O (for NO3 - )), remote sensing, and socio-economic development. We identify groundwater SO4 2- and NO3 - sources by combined use of δ34 S and Ca2+ /Na+ molar ratio and δ15 N and NO3 - /Na+ ratio, respectively...
October 27, 2018: Journal of Contaminant Hydrology
Brianne N Hicknell, Kevin G Mumford, Bernard H Kueper
In situ thermal treatment (ISTT) technologies have been applied at sites impacted by non-aqueous phase liquids (NAPLs). There is a need to establish expectations for the treatment of semi-volatile NAPLs, including those consisting primarily of polycyclic aromatic hydrocarbons (PAHs), and the potential benefits and limitations of partial NAPL removal. A series of laboratory experiments was conducted to investigate NAPL removal and soil concentrations during the heating of creosote-impacted sand, as well as aqueous concentrations during post-heating dissolution...
October 16, 2018: Journal of Contaminant Hydrology
María Laura Vázquez Juiz, Diego Soto Gómez, Paula Pérez Rodríguez, Marcos Paradelo, José Eugenio López Periago
Tunable Resistive Pulse Sensing, TRPS, is an emerging technique used in quantification and measuring the size (particle-by-particle) of viruses, exosomes and engineered colloidal spheres in biological fluids. We study the features of TRPS to enhance size characterization and quantification of submicron-sized microplastics, also called plastic microparticles, MP, in freshwater environments. We report alterations on the detection of the resistive pulses in the TRPS caused by humic acids, HA, during the size measurement of polystyrene microspheres used as MP surrogate...
October 16, 2018: Journal of Contaminant Hydrology
Bowen Li, Chunpeng Zhang, Yan Li, Chunyu Wen, Jun Dong, Meng Yao, Liming Ren
Recent laboratory studies have shown the injection of colloidal Mg(OH)2 could provide an effective and low cost alternative as a long term pH buffering system. In this study, Mg(OH)2 was modified by Tween 80 and SDS and the modified suspension had the properties of high stability, small particle size (the average particle diameter D50 was smaller than 1 μm) and negative charge (zeta potential = -14.26 mV at pH = 10.54). All of these properties demonstrated that colloidal Mg(OH)2 may have satisfactory transport performance in porous media...
October 15, 2018: Journal of Contaminant Hydrology
Li Meng, Rui Zuo, Jin-Sheng Wang, Jie Yang, Yan-Guo Teng, Rong-Tao Shi, Yuan-Zheng Zhai
Comparative analysis was performed of changing groundwater quality over ten years (2006-2016) by source apportionment and spatial distribution characteristics. This shallow groundwater in a typical riverside groundwater resource area was studied using principal component analysis (PCA) and factor analysis (FA), coupled with the absolute principal-component-score multiple-linear-regression (APCS-MLR) receptor model. The relationship among land-use types, hydro-chemical composition, and evolution of the quality of groundwater from natural and anthropogenic sources was demonstrated...
October 15, 2018: Journal of Contaminant Hydrology
N Sihota, B McAlexander, M Lyverse, K U Mayer
The changing landscape of fuel consumption related, in part, to increased engine efficiency and the inexpensive supply of natural gas, has led to the closure of multiple refineries. As the operational lifetime of many refineries exceeds 100 years, historical releases of oil and refined products is common. To evaluate remediation and rehabilitation options, there is a need to understand the rate and distribution of natural hydrocarbon mass losses across these large properties. Here, surficial CO2 flux measurements were used to evaluate naturally occurring hydrocarbon mass losses at a large-scale former refinery that has been closed since 1982...
October 13, 2018: Journal of Contaminant Hydrology
Agustín Spaltro, Matías Pila, Sandra Simonetti, Silvia Álvarez-Torrellas, Juan García Rodríguez, Danila Ruiz, Andres Díaz Compañy, Alfredo Juan, Patricia Allegretti
In this study, commercial activated carbons (GAB and CBP) were successfully used for the removal of two phenoxy acetic class-herbicides, 4-chloro-2-methyl phenoxy acetic acid and 2.4-dichlorophenoxy acetic acid (MCPA and 2.4-D) from aqueous solution. The adsorbent materials were characterized, and their equilibrium adsorption capacity was evaluated. The results suggest that the microporous properties of GAB activated carbon enhanced the adsorption capacity, in comparison to CBP carbon. Thus, the increasing in the ionic strength favored the adsorption removal of both pesticides, indicating that electrostatic interactions between the pollutant and the adsorbate surface are governing the adsorption mechanism, but increasing pH values decreased adsorption capacity...
October 12, 2018: Journal of Contaminant Hydrology
Gláucia da P Lima, Jessica R Meyer, Kamini Khosla, Kari E Dunfield, Beth L Parker
Dissolved phase contaminants, transported by diffusion into the low permeability matrix of fractured sedimentary rock, pose a challenge to groundwater cleanup efforts because this stored mass may persist even when the upgradient source zone is removed. In this context, if contaminant biodegradation takes place within the low permeability matrix, plume persistence may be substantially reduced. Therefore, it is important to characterize microbial communities within the low permeability, rock matrix pores, instead of only from groundwater samples, which represent biomass from fast flowing fractures...
October 4, 2018: Journal of Contaminant Hydrology
Malcolm S Field, William E Schiesser
A two-dimensional model for solute migration, transformation, and deposition in a phreatic solution conduit penetrating a karst aquifer is presented in which the solute is anthropogenic to the natural system. Transformation of a reacting solute in a solution conduit has generally been accepted as likely occurring but actual physical measurements and mathematical analyses of the suspected process have been generally minimally investigated, primarily because of the logistical difficulties and complexities associated with solute transport through solution conduits...
September 26, 2018: Journal of Contaminant Hydrology
Paul B Hatzinger, James F Begley, David R Lippincott, Adria Bodour, Rose Forbes
1,2-Dibromoethane (ethylene dibromide; EDB) is a probable human carcinogen that was historically added to leaded gasoline as a scavenger to prevent the build-up of lead oxide deposits in engines. Studies indicate that EDB is present at thousands of past fuel spill sites above its stringent EPA Maximum Contaminant Level (MCL) of 0.05 μg/L. There are currently no proven in situ options to enhance EDB degradation in groundwater to meet this requirement. Based on successful laboratory studies showing that ethane can be used as a primary substrate to stimulate the aerobic, cometabolic biodegradation of EDB to <0...
September 25, 2018: Journal of Contaminant Hydrology
Michael C Brooks, A Lynn Wood, Jaehyun Cho, Christine A P Williams, William Brandon, Michael D Annable
Source strength functions (SSF), defined as contaminant mass discharge or flux-averaged concentration from dense nonaqueous phase liquid (DNAPL) source zones as a function of time, provide a quantitative model of DNAPL source-zone behavior. Such information is useful for calibration of screening-level models to assist with site management decisions. We investigate the use of historic data collected during long-term monitoring (LTM) activities at a site in Rhode Island to predict the SSF based on temporal mass discharge measurements at a fixed location, as well as SSF estimation using mass discharge measurements at a fixed time from three spatially distributed control planes...
September 21, 2018: Journal of Contaminant Hydrology
Allen M Shapiro, Rebecca J Brenneis
Contaminants diffusing from fractures into the immobile porosity of the rock matrix are subject to prolonged residence times. Organic contaminants can adsorb onto organic carbonaceous materials in the matrix extending contaminant retention. An investigation of spatial variability of the fraction of organic carbon (foc ) is conducted on samples of rock core from seven closely spaced boreholes in a mudstone aquifer contaminated with trichloroethene (TCE). A total of 378 samples were analyzed at depths between 14 and 36 m below land surface...
September 13, 2018: Journal of Contaminant Hydrology
Charles J Paradis, Ji-Won Moon, Dwayne A Elias, Larry D McKay, Terry C Hazen
Polyfluorinated benzoic acids (PBAs) can be used as non-reactive tracers to characterize reactive mass transport mechanisms in groundwater. The use of PBAs as non-reactive tracers assumes that their reactivities are negligible. If this assumption is not valid, PBAs may not be appropriate to use as non-reactive tracers. In this study, the reactivity of two PBAs, 2,6-difluorobenzoic acid (2,6-DFBA) and pentafluorobenzoic acid (PFBA), was tested in situ. A series of two single-well push-pull tests were conducted in two hydrogeologically similar, yet spatially distinct, groundwater monitoring wells...
September 5, 2018: Journal of Contaminant Hydrology
Saeid Shafieiyoun, Neil R Thomson, Andrew P Brey, Chris M Gasinski, William Pence, Mike Marley
Methods to remediate soil and groundwater contamination at former manufactured gas plant (FMGP) sites are scarce. The objective of this study was to investigate the ability of two chemical oxidants (persulfate and permanganate) to degrade FMGP residuals in a dynamic system representative of in situ conditions. A series of physical model trials supported by aqueous and slurry batch experiments using impacted sediments collected from a FMGP site were conducted. To explore treatment expectations a screening model constrained by the experimental data was employed...
September 4, 2018: Journal of Contaminant Hydrology
Esa Puukko, Jukka Lehto, Antero Lindberg, Mikko Voutilainen
This study aims to determine upscaling factors for the radionuclides' distribution coefficients (Kd ) on crushed rocks to intact rock for the safety analysis of radionuclide migration from spent nuclear fuel in bedrock towards biosphere. Here we report the distribution coefficients for intact rock determined by electromigration sorption experiments and compare the results with those from recently performed batch sorption experiments. In total 34 rock samples, representing three typical rock types from Olkiluoto Finland, were studied in order to determine distribution coefficients, effective diffusion coefficients and porosities using the electromigration sorption experiments, formation factor experiments and porosity measurement...
September 2, 2018: Journal of Contaminant Hydrology
Vagner Tebaldi de Queiroz, Mariane Martins Azevedo, Iana Pedro da Silva Quadros, Adilson Vidal Costa, Atanásio Alves do Amaral, Gleissy Mary Amaral Dino Alves Dos Santos, Ronie Silva Juvanhol, Lucas Arthur de Almeida Telles, Alexandre Rosa Dos Santos
The extensive use of pesticides in agricultural practices has been associated with human health problems and environmental contamination worldwide. Brazil is the largest consumer of pesticides in the world and Espírito Santo State stands out as the second Brazilian producer of coffee. However, there is no information about environmental impact of coffee producing at Itapemirim River Basin (IRB) region, Espírito Santo State, Brazil; hence a simple and quick method using open access softwares (AGROSCRE and ARAquá Web) to estimate surface entrainment and pesticide leaching potential was carried out...
August 30, 2018: Journal of Contaminant Hydrology
Beiyi Xu, Guangcai Wang, Qiang Yang, Yan Zheng
Shallow groundwater in alluvial plains is vulnerable to contamination due to infiltration of pollutants from anthropogenic activities. In the alluvial plain of the Yangtze River near Poyang Lake, a silicone monomer industrial park was found to discharge undisclosed amount of effluents containing high levels of hydrochloric acid and total dissolved solids into ponds and ditches that in turn, displayed characteristics of acidic water with high total dissolved solids. However, most shallow groundwater (n = 35, depth 5...
August 27, 2018: Journal of Contaminant Hydrology
Noelia Muskus, Ronald W Falta
A semi-analytical/numerical method for modeling matrix diffusion in heterogeneous and fractured groundwater systems is developed. This is a significant extension of the Falta and Wang (2017) method that only applied to diffusion in an aquitard of infinite thickness. The current solution allows for the low permeability matrix to be embedded within a numerical gridblock, having finite average thickness, a specified volume fraction and a specified interfacial area with the high permeability domain. The new formulation also allows for coupled parent-daughter decay reactions with multiple species that each have independent retardation factors, decay rates, and yield coefficients in both the high and low permeability parts of the system...
November 2018: Journal of Contaminant Hydrology
Jun Zhou, Xiaosi Su, Geng Cui
Groundwater reactive transport models that consider the coupling of hydraulic and biochemical processes are vital tools for predicting the fate of groundwater contaminants and effective groundwater management. The models involve a large number of parameters whose specification greatly affects the model performance. Thus model parameters calibration is crucial to its successful application. The Bayesian inference framework implemented by Markov chain Monte Carlo (MCMC) sampling provides a comprehensive framework to estimate the model parameters...
September 2018: Journal of Contaminant Hydrology
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