Distribution coefficients (K(d) values) describe contaminant partitioning between liquids and solids for linear sorption at equilibrium conditions. If experimentally-determined K(d) values do not represent sorption equilibria, errors are introduced in contaminant transport models. These errors may be further propagated when K(d) values are used to compare contaminant mobility under different ch...

Insects are integral to most freshwater and terrestrial food webs, but due to their accumulation of environmental pollutants they are also contaminant vectors that threaten reproduction, development, and survival of consumers. Metamorphosis from larvae to adult can cause large chemical changes in insects, altering contaminant concentrations and fractionation of chemical tracers used to establis...

Biota-sediment accumulation factors (BSAF) were calculated for Diporeia spp. and oligochaete worms exposed to polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) from field-collected sediment. These data were compared to the contaminant fraction extracted from sediment with Tenax resin using a 24 h extraction. A previous laboratory study suggested a linear relationship ...

This study includes isolation, purification, and identification of algae from different environmental places (Tigris River and canal around AlJadriah) during February 2008. Nine unialgal cultures were obtainedwhich included 4 species of blue-green algae, 4 species of green algae, and 1 species of diatoms. However, contaminant bacteria and fungi were isolated from 4 of these algal cultures which...

We report development of a novel parameter for quantifying the amount of humic and fulvic acids per unit surface area in a particular soil. This quantity, the "humic coverage index" (HCI), provides a measurement of the relative spatial extents and/or thicknesses of the humic/fulvic overlayers in different soils, and, therefore, can be used in modeling various soils' behavior in sequestration pr...

BACKGROUND The North American Great Lakes are home to > 140 types of fish and are famous for recreational and commercial fishing. However, the presence of toxic substances has resulted in the issuance of fish consumption advisories that are typically based on the most restrictive contaminant. OBJECTIVES We investigated whether these advisories, which typically neglect the existence of a mixtu...

Pollutants in groundwater aquifers may constitute a significant human health risk. A large variation in response may result among human populations experiencing the same level and duration of exposure to pollutants. Variability in response, as a result of exposure to a carcinogenic contaminant such as trichloroethylene (TCE), can be represented by a distribution function of safe doses. Spatial ...

In this study, an integrated in situ remediation technique which couples electrokinetics with adsorption, using locally produced granular activated carbon from date palm pits in the treatment zones that are installed directly to bracket the contaminated soils at bench-scale, is investigated. Natural saline-sodic clay soil, spiked with contaminant mixture (kerosene, phenol, Cr, Cd, Cu, Zn, Pb, a...

Metallic iron (Fe) is often reported as a reducing agent for environmental remediation. There is still controversy as to whether Fe plays any significant direct role in the process of contaminant reductive transformation. The view that Fe is mostly a generator of reducing agents (e.g. H, H2 and Fe) and Fe oxyhydroxides has been either severely refuted or just tolerated. The tolerance is based o...

In this study, a stand-alone sediment and contaminant model, SEDDEER (Sediment Deposition and Erosion), is presented. The model simulates one water box and underlying (multiple) sediment bed layers, and was developed for incorporation into water quality models. The processes incorporated in the model are: settling and deposition, resuspension, equilibrium adsorption/desorption, sediment-water i...