to examine hydraulics of lnapls in soil, the retention curves of diesel fuel and water were both determined by hanging column method. the soil retention parameters were obtained based on van genuchten, brooks-corey and campbell’s models. in addition, the soil hydraulic conductivity for both fluids were predicted based on mualem- brooks-corey, burdine- brooks-corey, mualem-van genuchten and camp...

When investigating the treatment of contaminated soils, the application of biotreatment is growing rapidly. Factors influencing this rapid growth include that the bioremediation processes are cost-efficient, safe, and nature-based. In the past, thermal, chemical, and physical treatment methods have failed to eliminate the pollution problem because those methods only shift the pollution to a new...

Interrelationships between pyrogenic polycyclic aromatic hydrocarbons (PAHs) were assessed in air, soil, water, sediment, and tree leaves by using multi-media monitoring data. Concurrent concentration measurements were taken bimonthly for a year for the multi-media at urban and suburban sites. PAH level correlations between air and other media were observed at the urban site but were less clear...

Soils are the major terrestrial reservoir of persistent organic pollutants, and thus net volatilization from soil, when it happens, may exert a control on the atmospheric occurrence and variability of organic pollutants. Here, we report and discuss the concentrations of legacy organochlorine pesticides (OCPs) such as hexachlorobenzene (HCB), hexaclorocyclohexanes (HCH) and dichlorodiphenyltrich...

Radon diffusion through soil and into air is investigated. The solution of the relevant diffusion equation is given using the explicit finite difference method. Results from a two-medium model (soil-air) are compared to those from a simplified single-medium model (soil alone). The latter are an underestimate in early stages of the diffusion process. Later on, the two models match closely and ei...

An experimental tracer addition of (84)Sr to an unpolluted temperate forest site in southern Chile, as well as the natural variation of (87)Sr/(86)Sr within plants and soils, indicates that mechanisms in shallow soil organic horizons are of key importance for retaining and recycling atmospheric cation inputs at scales of decades or less. The dominant tree species Nothofagus nitida feeds nearly ...

Urban areas are major contributors to air pollution and climate change, causing impacts on human health that are amplified by the microclimatological effects of buildings and grey infrastructure through the urban heat island (UHI) effect. Urban greenspaces may be important in reducing surface temperature extremes, but their effects have not been investigated at a city-wide scale. Across a mid-s...

(1) Airflow is induced in the subsurface by applying a pressure gradient through vertical or horizontal wells or horizontal trenches. In SVE, this is usually accomplished by withdrawal, rather than injection, of air. The SVE gas flow increases rates of contaminant mass transfer to air in the unsaturated zone by evaporation of NAPL, volatilization of contaminants dissolved in pore water, and des...

A new system for soil respiration measurement [P. Rochette, L.B. Flanagan, E.G. Gregorich. Separating soil respiration into plant and soil components using analyses of the natural abundance of carbon-13. Soil Sci. Soc. Am. J., 63, 1207-1213 (1999).] was modified in order to collect soil-derived CO2 for stable isotope analysis. The aim of this study was to assess the suitability of this modified...