The understanding of the gaseous adsorption process and the parameters of volatile organic compounds such as organic solvents or fuels onto soils is very important in the analysis of the transport or fate of these chemicals in soils. Batch adsorption experiments with six different treatments were conducted to determine the adsorption of isohexane, a gaseous aliphatic, onto volcanic ash soil (Ta...

An improved particle swarm optimization (IPSO) was proposed and the intelligent algorithms such as IPSO, genetic algorithm (GA), and simulated annealing algorithm (SA) were introduced to determine parameters of Van Genuchten (VG) model for soil water retention curve (SWRC) of four typical agricultural soil textures (clay, clay loam, silt loam and sand loam) in China. For comparison, the SWRC in...

OBJECTIVES To quantify personal time-weighted average respirable dust and quartz exposure on a sandy, a sandy loam, and a clay soil farm in the Free State and North West provinces of South Africa and to ascertain whether soil type is a determinant of exposure to respirable quartz. METHODS Three farms, located in the Free State and North West provinces of South Africa, had their soil type conf...

With global change expected to alter aspects of the carbon (C) cycle, empirical data describing how microorganisms function in different environmental conditions are needed to increase predictive capabilities of microbially-driven decomposition models. Given the importance of accelerated C fluxes during early decay in C cycling, we characterized how varying litter qualities (maple vs. oak) and ...

Although groundwater quality depends on microbial processes in the soil treatment area (STA) of onsite wastewater treatment systems (OWTS), our understanding of the development of these microbial communities is limited. We examined the bacterial communities of sand, sandy loam, and clay STAs at different depths in response to septic tank effluent (STE) addition using mesocosms. Terminal restric...

Estimation of changes in crop yields is currently based on projections of atmospheric General Circulation Models (GCM) and the use of crop simulators. Crop simulators require daily input of environmental variables. GCMs produce monthly projections of climatic variables. Our objective was to explore the possibility of using monthly weather projections in yield estimates. We considered atmospheri...

Bacteria transport in soils primarily occurs through soil mesopores and macropores (e.g., biopores and cracks). Field research has demonstrated that biopores and subsurface drains can be hydraulically connected. This research was conducted to investigate the importance of surface connected and disconnected (buried) biopores on Escherichia coli (E. coli) transport when biopores are located near ...