Chlorinated solvents such as trichloroethene (TCE) and tetrachloroethene (PCE) are widespread groundwater contaminants often released as dense nonaqueous phase liquids (DNAPLs). These contaminants are difficult to remediate, particularly their source zones. This review summarizes the progress made in improving DNAPL source zone remediation over the past decade, and is structured to highlight th...

The impact of industrial effluent on the Oruku River in southwestern region of Nigeria was investigated. Surface water, sediment, ground water and industrial effluent samples were obtained bimonthly for 18 months (March 2005 to September 2006). Effluent characteristics varied widely with averages of DO (4.25±1.3 mg/L), BOD (27.5±43 mg/L), Pb (0.41±0.26 mg/L), Cr (0.26±0.48 mg/L) and Ni (0.19±0....

The contribution of macropore flow to phosphorus (P) loadings in tile-drained agricultural landscapes remains poorly understood at the field scale, despite the recognized deleterious impacts of contaminant transport via macropore pathways. A new subroutine that couples existing matrix-excess and matrix-desiccation macropore flow theory and a modified P routine is implemented in the Agricultural...

Recharge and contamination of karst aquifers often occur via the unsaturated zone, but the functioning of this zone has not yet been fully understood. Therefore, irrigation and tracer experiments, along with monitoring of rainfall events, were used to examine water percolation and the transport of solutes, particles, and fecal bacteria between the land surface and a water outlet into a shallow ...

Purkinje cells of the cerebellar cortex and neurons in the deep cerebellar nuclei (DCN) were among the first central neurons to be studied extensively through the use of in vitro preparations. Yet, the degree to which the patterns of action potential (“spike”) output recorded in these cells in vitro match those recorded in vivo has been a matter of debate and uncertainty. We have identified rel...

Method 200.8 is a well-established method promulgated by the U.S. Environmental Protection Agency (EPA) for the analysis of ground waters, surface waters, drinking waters, and wastewaters by inductively coupled plasma mass spectrometry (ICP-MS). The method was first published in 1990 to support the National Primary Drinking Water Regulations (NPDWR), which specified maximum contaminant levels (...

Purely stochastic methods can yield useful prediction models of contaminant arrival-time distributions derived from advective-dispersive transport in a variety of one-dimensional environments. Two different models are considered, both relating to dispersion of a brief pulse of conservative contaminant in a steady flow system. The first model considers the arrival-time of a contaminant pulse in ...

solute transport in unsaturated porous media can be viewed as a coupled phenomenon with waterand heat transport, together with mechanical behaviour of media. in this paper, solute transport is formulatedmathematically considering heat and water flow in deformable porous media. advection, dispersion anddiffusion of chemical species in the liquid phase are considered. convection and conduction fo...

UNLABELLED In case contaminants are found in enclosed environments such as aircraft cabins or buildings, it is useful to find the contaminant sources. One method to locate contaminant sources is by inverse computational fluid dynamics (CFD) modeling. As the inverse CFD modeling is ill posed, this paper has proposed to solve a quasi-reversibility (QR) equation for contaminant transport. The equa...

Electrokinetic extraction is an emerging technology that has shown considerable potential for efficient and effective removal of both inorganic and organic contaminants from fine-grained soils of low hydraulic conductivity and large specific area when conditions are favorable. The cleanup technology is basically the application of a direct-current electric field across contaminated soils throug...