Showing papers in "Journal of Contaminant Hydrology in 1992"

TL;DR: In this article, a sequence of redoxe zones is identified from groundwater chemical analysis from an old municipal landfill allowing leachate, rich in dissolved organic carbon, to enter a shallow sandy aerobic aquifer, and the redox zone sequence is believed to be key in controlling the fate of reactive pollutants leached from the landfill.

TL;DR: In this article, the authors reviewed several reactions pertinent to remediating contaminated groundwaters via hydrogen peroxide (H2O2) addition, including microbial catalase and several inorganic catalysts such as iron oxide species.

TL;DR: In this paper, the metal removal process from acid mine drainage was studied in an experimental constructed wetland in the Idaho Springs-Central City mining district of Colorado, which was designed to passively remove heavy metals from the mine drainage flowing from the Big Five Tunnel.

TL;DR: In this article, the first 20 m of leachate pollution plume are methanogenic/sulfidogenic, judged on the chemistry of the groundwater, followed by a significant ferrogenic zone exhibiting a substantial capacity to degrade the organic compounds.

TL;DR: In this paper, three natural-gradient injection experiments in the Borden aquifer (Ontario, Canada) (∼ 100-300 days in duration) and a 452-day laboratory microcosm experiment were performed to evaluate the biotransformation of BTEX (benzene, toluene, ethyl benzene and o -, m -, p -xylenes) derived from gasoline under anaerobic, denitrifying conditions.

TL;DR: In this paper, three types of experiments were conducted to assess the potential for enhancing the in situ biodegradation of nine aromatic hydrocarbons in anaerobic leachate-impacted aquifers at North Bay, Ontario, and at Canada Forces Base Borden.

TL;DR: In this article, a series of experiments were performed to characterize the morphologic distribution of nonaqueous-phase liquids (NAPL's) at residual saturation, as a function of porous medium size.

TL;DR: In this paper, a large number of field plot experiments were performed to characterize the downward flow of three pesticides (atrazine, napropamide and prometryn) under various soil water regimes and soil surface conditions.

TL;DR: In this article, a laboratory diffusion-test estimation of the diffusion coefficient (D ) and the adsorption coefficient (K d ) for several volatile organic species in a saturated, relatively undisturbed, clayey soil is presented.

TL;DR: A published hysteretic saturation-pressure (S-P) model, which predicts fluid distributions before and after subsurface contamination by a nonaqueous phase liquid (NAPL), is tested in this paper.

TL;DR: In this article, the impact of variations in pore-water velocity on the nonequilibrium sorption and transport of organic chemicals was investigated and the results of the experiments were analyzed by using a one-dimensional advectivedispersive transport model, wherein sorption is considered instantaneous for a fraction of the sorbent and rate-limited for the remainder.

TL;DR: Fractures significantly increased the amount of microsphere transport; 80–99% of the spheres were retained in experiments with tubes inserted compared to 99–100% without tubes; these observations have implications for monitoring colloid transport in natural systems.

TL;DR: Sorption of hexadecyltrimethylammonium chloride (HDTMA), a cationic surfactant, on aquifer material from Columbus AFB, Mississippi, U.S.A., was examined in this article.

TL;DR: In this paper, the authors used both laboratory-column and field-column experiments to estimate retardation coefficients of five halogenated hydrocarbons (bromoform, carbon tetrachloride, tetrACHloroethylene, 1,2-dichlorobenzene and hexachloroethane) in the Borden aquifer.

TL;DR: In this article, the diffusion coefficients for four volatile organic compounds of environmental concern, benzene, trichloroethylene, toluene and chlorobenzene, were measured on cores of saturated, unweathered glaciolacustrine clay obtained from boreholes at a hazardous waste disposal site near Sarnia, Ontario.

TL;DR: In this paper, anionic surfactants and their biodegradation intermediates were isolated from field samples by ion exchange and fractionated by solvent extraction and adsorption chromatography.

TL;DR: In this article, an approach based on electrode kinetics to interpreting measured redox potentials is presented, and sensitivity analysis of the effects of these unknown parameters on the potential is presented.

TL;DR: In this article, the vaporization modes of single and binary hydrocarbon liquids held in homogeneous and heterogeneous porous media during air venting were delineated using a two-dimensional apparatus which allowed visual observation of the evolving geometry of the liquid contaminant pool.

TL;DR: In this article, the LEACHM model was evaluated using data from a field experiment conducted in Lancaster County, Pennsylvania, U.S.A. Many of the parameter input values were the means of determinations for soil samples from the field site.

TL;DR: In this article, the authors investigated the associations of free-living bacteria (FLB) and dissolved organic contaminants in a 4 km-long plume of sewage-contaminated groundwater.

TL;DR: In this paper, a method is proposed to measure Pc−S drainage and imbition relationships for TCE-air and TCEwater systems at points along a 1m-long column with the help of a γ-radiation system and from knowledge of the fluid pressure distributions at hydraulic equilibrium.

TL;DR: In this article, it is suggested that intensive irrigation with water imported from the Sea of Galilee induced flow in old fractures and in solution channels developed in the underlying chalks, which reached groundwater and ultimately flowed into the adjacent sandy Coastal Plain aquifer.

TL;DR: In this article, the dissolution and transport of trapped nonaqueous phase liquid hydrocarbon (oil) was examined in a laboratory column study using aquifer material from a site contaminated with aviation gasoline.

TL;DR: In this article, a study was conducted to identify the processes affecting the distribution of nitrate in the unsaturated and saturated zones beneath an agricultural field and to assess how each process is influenced by factors associated with slope position.

TL;DR: In this paper, a waterworks at Fuhrberg, Germany, was used to obtain samples of humic substances, which had a bimodal molecular size distribution with ∼40% of the total carbon in the 50,000,100,000-D (nominal molecular weight, NMW, in daltons) size fraction and ∼50% of all the carbon in <10,000 -D (nondimensional molecular size fraction).

TL;DR: A review of recent advances in the chemistry of abiotic redox transformations of organic pollutants in anaerobic ecosystems is presented in this article, where the types of functional groups that undergo reaction and the findings concerning physical and chemical parameters of ecosystems that govern the rates and products of reductive transformations are discussed.

TL;DR: In this paper, the authors investigated the prolongation of in situ remediation due to aquifer heterogeneities in a series of Monte Carlo simulations and proposed a deterministic reactive transport model for each aquifer realization with a coupled two-dimensional numerical model accounting for concentration changes due to advection, dispersion and aerobic microbial growth.

TL;DR: In this article, the spreading coefficient, C sp, determines whether an organic immiscible liquid, OIL, will form a lens (C sp C sp > 0) on a water surface, and the influence of such interfacial spreading phenomena on OIL infiltration in a pristine vadose zone, was tested in glass-bead columns, moistened with water, by using OIL's with different C sp.

TL;DR: In this paper, a tracer experiment demonstrated higher downward water and solute transport in the fracture fill beneath the fissure relative to adjacent sediments and the corresponding moisture velocities in fissured sediments ranged from 10 to 70 mm yr −1.