journal
MENU ▼
Read by QxMD icon Read
search

Journal of Contaminant Hydrology

journal
https://www.readbyqxmd.com/read/28641890/a-comparative-research-of-different-ensemble-surrogate-models-based-on-set-pair-analysis-for-the-dnapl-contaminated-aquifer-remediation-strategy-optimization
#1
Zeyu Hou, Wenxi Lu, Haibo Xue, Jin Lin
Surrogate-based simulation-optimization technique is an effective approach for optimizing the surfactant enhanced aquifer remediation (SEAR) strategy for clearing DNAPLs. The performance of the surrogate model, which is used to replace the simulation model for the aim of reducing computation burden, is the key of corresponding researches. However, previous researches are generally based on a stand-alone surrogate model, and rarely make efforts to improve the approximation accuracy of the surrogate model to the simulation model sufficiently by combining various methods...
June 15, 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28651901/benchmarking-numerical-codes-for-tracer-transport-with-the-aid-of-laboratory-scale-experiments-in-2d-heterogeneous-porous-media
#2
Fadji Hassane Maina, Philippe Ackerer, Anis Younes, Alberto Guadagnini, Brian Berkowitz
We present a combined experimental and numerical modeling study that addresses two principal questions: (i) is any particular Eulerian-based method used to solve the classical advection-dispersion equation (ADE) clearly superior (relative to the others), in terms of yielding solutions that reproduce BTCs of the kind that are typically sampled at the outlet of a laboratory cell? and (ii) in the presence of matches of comparable quality against such BTCs, do any of these methods render different (or similar) numerical BTCs at locations within the domain? To address these questions, we obtained measurements from carefully controlled laboratory experiments, and employ them as a reference against which numerical results are benchmarked and compared...
June 7, 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28645723/doublet-tracer-tests-to-determine-the-contaminant-flushing-properties-of-a-municipal-solid-waste-landfill
#3
N D Woodman, T C Rees-White, R P Beaven, A M Stringfellow, J A Barker
This paper describes a programme of research investigating horizontal fluid flow and solute transport through saturated municipal solid waste (MSW) landfill. The purpose is to inform engineering strategies for future contaminant flushing. Solute transport between injection/abstraction well pairs (doublets) is investigated using three tracers over five separate tests at well separations between 5m and 20m. Two inorganic tracers (lithium and bromide) were used, plus the fluorescent dye tracer, rhodamine-WT. There was no evidence for persistent preferential horizons or pathways at the inter-well scale...
June 7, 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28583424/conservative-strategy-based-ensemble-surrogate-model-for-optimal-groundwater-remediation-design-at-dnapls-contaminated-sites
#4
Qi Ouyang, Wenxi Lu, Jin Lin, Wenbing Deng, Weiguo Cheng
The surrogate-based simulation-optimization techniques are frequently used for optimal groundwater remediation design. When this technique is used, surrogate errors caused by surrogate-modeling uncertainty may lead to generation of infeasible designs. In this paper, a conservative strategy that pushes the optimal design into the feasible region was used to address surrogate-modeling uncertainty. In addition, chance-constrained programming (CCP) was adopted to compare with the conservative strategy in addressing this uncertainty...
May 31, 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28595989/volume-reduction-outweighs-biogeochemical-processes-in-controlling-phosphorus-treatment-in-aged-detention-systems
#5
Asmita Shukla, Sanjay Shukla, Michael D Annable, Alan W Hodges
Stormwater detention areas (SDAs) play an important role in treating end-of-the-farm runoff in phosphorous (P) limited agroecosystems. Phosphorus transport from the SDAs, including those through subsurface pathways, are not well understood. The prevailing understanding of these systems assumes that biogeochemical processes play the primary treatment role and that subsurface losses can be neglected. Water and P fluxes from a SDA located in a row-crop farm were measured for two years (2009-2011) to assess the SDA's role in reducing downstream P loads...
May 29, 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28619599/impact-of-sulfuric-and-nitric-acids-on-carbonate-dissolution-and-the-associated-deficit-of-co2-uptake-in-the-upper-middle-reaches-of-the-wujiang-river-china
#6
Qi-Bo Huang, Xiao-Qun Qin, Peng-Yu Liu, Lian-Kai Zhang, Chun-Tian Su
Carbonate weathering and the CO2 consumption in karstic area are extensive affected by anthropogenic activities, especially sulfuric and nitric acids usage in the upper-middle reaches of Wujiang River, China. The carbonic acid would be substituted by protons from sulfuric and nitric acids which can be reduce CO2 absorption. Therefore, The goal of this study was to highlight the impacts of sulfuric and nitric acids on carbonate dissolution and the associated deficit of CO2 uptaking during carbonate weathering...
May 25, 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28495233/sorption-and-speciation-of-iodine-in-groundwater-system-the-roles-of-organic-matter-and-organic-mineral-complexes
#7
Junxia Li, Hailing Zhou, Yanxin Wang, Xianjun Xie, Kun Qian
Characterizing the properties of main host of iodine in soil/sediment and the geochemical behaviors of iodine species are critical to understand the mechanisms of iodine mobilization in groundwater systems. Four surface soil and six subsurface sediment samples were collected from the iodine-affected area of Datong basin in northern China to conduct batch experiments and to evaluate the effects of NOM and/or organic-mineral complexes on iodide/iodate geochemical behaviors. The results showed that both iodine contents and kf-iodate values had positive correlations with solid TOC contents, implying the potential host of NOM for iodine in soil/sediment samples...
April 24, 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28434529/stochastic-multicomponent-reactive-transport-analysis-of-low-quality-drainage-release-from-waste-rock-piles-controls-of-the-spatial-distribution-of-acid-generating-and-neutralizing-minerals
#8
Daniele Pedretti, K Ulrich Mayer, Roger D Beckie
In mining environmental applications, it is important to assess water quality from waste rock piles (WRPs) and estimate the likelihood of acid rock drainage (ARD) over time. The mineralogical heterogeneity of WRPs is a source of uncertainty in this assessment, undermining the reliability of traditional bulk indicators used in the industry. We focused in this work on the bulk neutralizing potential ratio (NPR), which is defined as the ratio of the content of non-acid-generating minerals (typically reactive carbonates such as calcite) to the content of potentially acid-generating minerals (typically sulfides such as pyrite)...
April 12, 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28442237/long-term-ert-monitoring-of-biogeochemical-changes-of-an-aged-hydrocarbon-contamination
#9
David Caterina, Adrian Flores Orozco, Frédéric Nguyen
Adequate management of contaminated sites requires information with improved spatio-temporal resolution, in particular to assess bio-geochemical processes, such as the transformation and degradation of contaminants, precipitation of minerals or changes in groundwater geochemistry occurring during and after remediation procedures. Electrical Resistivity Tomography (ERT), a geophysical method sensitive to pore-fluid and pore-geometry properties, permits to gain quasi-continuous information about subsurface properties in real-time and has been consequently widely used for the characterization of hydrocarbon-impacted sediments...
April 10, 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28433208/elucidating-the-fate-of-a-mixed-toluene-dhm-methanol-and-i-propanol-plume-during-in-situ-bioremediation
#10
E Verardo, O Atteia, H Prommer
Organic pollutants such as solvents or petroleum products are widespread contaminants in soil and groundwater systems. In-situ bioremediation is a commonly used remediation technology to clean up the subsurface to eliminate the risks of toxic substances to reach potential receptors in surface waters or drinking water wells. This study discusses the development of a subsurface model to analyse the performance of an actively operating field-scale enhanced bioremediation scheme. The study site was affected by a mixed toluene, dihydromyrcenol (DHM), methanol, and i-propanol plume...
April 6, 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28442238/the-influence-of-small-scale-interlayer-heterogeneity-on-ddt-removal-efficiency-for-flushing-technology
#11
Xingwei Wang, Jiajun Chen
With an aim to investigate the influence of small-scale interlayer heterogeneity on DDT removal efficiency, batch test including surfactant-stabilized foam flushing and solution flushing were carried out. Two man-made heterogeneous patterns consisting of coarse and fine quartz sand were designed to reveal the influencing mechanism. Moreover, the removal mechanism and the corresponding contribution by foam flushing were quantitatively studied. Compared with surfactant solution flushing, the DDT removal efficiency by surfactant-stabilized foam flushing increased by 9...
April 5, 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28559008/modelling-mass-transfer-during-venting-soil-vapour-extraction-non-aqueous-phase-liquid-gas-mass-transfer-coefficient-estimation
#12
D Esrael, M Kacem, B Benadda
We investigate how the simulation of the venting/soil vapour extraction (SVE) process is affected by the mass transfer coefficient, using a model comprising five partial differential equations describing gas flow and mass conservation of phases and including an expression accounting for soil saturation conditions. In doing so, we test five previously reported quations for estimating the non-aqueous phase liquid (NAPL)/gas initial mass transfer coefficient and evaluate an expression that uses a reference NAPL saturation...
July 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28554827/field-scale-forward-and-back-diffusion-through-low-permeability-zones
#13
Minjune Yang, Michael D Annable, James W Jawitz
Understanding the effects of back diffusion of groundwater contaminants from low-permeability zones to aquifers is critical to making site management decisions related to remedial actions. Here, we combine aquifer and aquitard data to develop recommended site characterization strategies using a three-stage classification of plume life cycle based on the solute origins: aquifer source zone dissolution, source zone dissolution combined with back diffusion from an aquitard, and only back diffusion. We use measured aquitard concentration profile data from three field sites to identify signature shapes that are characteristic of these three stages...
July 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28549725/understanding-the-hydrologic-control-of-n-cycle-effect-of-water-filled-pore-space-on-heterotrophic-nitrification-denitrification-and-dissimilatory-nitrate-reduction-to-ammonium-mechanisms-in-unsaturated-soils
#14
C Mekala, Indumathi M Nambi
Irrigation practice will be effective if it supplies optimal water and nutrients to crops and act as a filter for contaminants leaching to ground water. There is always a scope for improving the fertilizer use efficiency and scheduling of wastewater irrigation if the fate and transport of nutrients particularly nitrogenous compounds in the soil are well understood. In the present study, nitrogen transport experiments for two different agricultural soils are performed under varying saturation 33, 57, 78% water filled pore space for sandy soil 1 and 52, 81 and 96% for loam soil 2...
July 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28545848/identification-of-immiscible-napl-contaminant-sources-in-aquifers-by-a-modified-two-level-saturation-based-imperialist-competitive-algorithm
#15
H R Ghafouri, M Mosharaf-Dehkordi, B Afzalan
A simulation-optimization model is proposed for identifying the characteristics of local immiscible NAPL contaminant sources inside aquifers. This model employs the UTCHEM 9.0 software as its simulator for solving the governing equations associated with the multi-phase flow in porous media. As the optimization model, a novel two-level saturation based Imperialist Competitive Algorithm (ICA) is proposed to estimate the parameters of contaminant sources. The first level consists of three parallel independent ICAs and plays as a pre-conditioner for the second level which is a single modified ICA...
July 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28545847/sources-and-behaviour-of-nitrogen-compounds-in-the-shallow-groundwater-of-agricultural-areas-poyang-lake-basin-china
#16
Evgeniya Soldatova, Natalia Guseva, Zhanxue Sun, Valeriy Bychinsky, Pascal Boeckx, Bai Gao
Nitrogen contamination of natural water is a typical problem for various territories throughout the world. One of the regions exposed to nitrogen pollution is located in the Poyang Lake basin. As a result of agricultural activity and dense population, the shallow groundwater of this area is characterised by a high concentration of nitrogen compounds, primarily NO3(-), with the concentration varying from 0.1mg/L to 206mg/L. Locally, high ammonium content occurs in the shallow groundwater with low reduction potential Eh (<100mV)...
July 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28528771/comparison-of-residual-napl-source-removal-techniques-in-3d-metric-scale-experiments
#17
O Atteia, F Jousse, G Cohen, P Höhener
This study compared four treatment techniques for the removal of a toluene/n-decane as NAPL (Non Aqueous Phase Liquid) phase mixture in identical 1 cubic meter tanks filled with different kind of sand. These four treatment techniques were: oxidation with persulfate, surfactant washing with Tween80®, sparging with air followed by ozone, and thermal treatment at 80°C. The sources were made with three lenses of 26×26×6.5cm, one having a hydraulic conductivity similar to the whole tank and the two others a value 10 times smaller...
July 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28479186/dissolution-enhancement-and-mathematical-modeling-of-removal-of-residual-trichloroethene-in-sands-by-ozonation-during-flushing-with-micro-nano-bubble-solution
#18
Menghau Sung, Chun-Hao Teng, Tsung-Hsien Yang
Soil flushing using micro-nano-sized bubbles (MNB) in water as the flushing solution was tested in laboratory sand columns for the cleanup of residual trichloroethene (TCE) non-aqueous-phase-liquid (NAPL). Experiments considering flushing with MNB as well as ozone MNB (OZMNB) in water to treat soils contaminated with residual TCE liquid were conducted to examine effects of ozone on dissolution enhancement. The degrees of residual TCE saturation in soils, ranging from 0.44% to 7.6%, were tested. During flushings, aqueous TCE concentrations at the column exit were monitored and TCE masses remained in the columns after flushing were determined...
July 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28412014/continuum-based-dfn-consistent-numerical-framework-for-the-simulation-of-oxygen-infiltration-into-fractured-crystalline-rocks
#19
Paolo Trinchero, Ignasi Puigdomenech, Jorge Molinero, Hedieh Ebrahimi, Björn Gylling, Urban Svensson, Dirk Bosbach, Guido Deissmann
We present an enhanced continuum-based approach for the modelling of groundwater flow coupled with reactive transport in crystalline fractured rocks. In the proposed formulation, flow, transport and geochemical parameters are represented onto a numerical grid using Discrete Fracture Network (DFN) derived parameters. The geochemical reactions are further constrained by field observations of mineral distribution. To illustrate how the approach can be used to include physical and geochemical complexities into reactive transport calculations, we have analysed the potential ingress of oxygenated glacial-meltwater in a heterogeneous fractured rock using the Forsmark site (Sweden) as an example...
May 2017: Journal of Contaminant Hydrology
https://www.readbyqxmd.com/read/28390700/effects-of-crude-oil-on-water-and-tracer-movement-in-the-unsaturated-and-saturated-zones
#20
Geoffrey N Delin, William N Herkelrath
A tracer test was conducted to aid in the investigation of water movement and solute transport at a crude-oil spill site near Bemidji, Minnesota. Time of travel was measured using breakthrough curves for rhodamine WT and bromide tracers moving from the soil surface through oil-contaminated and oil-free unsaturated zones to the saturated zone. Results indicate that the rates of tracer movement were similar in the oil-free unsaturated and saturated zones compared to the oily zones. These results are somewhat surprising given the oil contamination in the unsaturated and saturated zones...
May 2017: Journal of Contaminant Hydrology
journal
journal
29832
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"