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Global distillation or the Grasshopper effect is the geochemical process by which certain chemicals, most notably persistent organic pollutants (POPs), are vaporized and transported from warmer to colder regions of the Earth, particularly the poles and mountain tops, where they condense.
Soil vapor extraction (SVE) is a physical treatment process for in situ remediation of volatile contaminants in vadose zone (unsaturated) soils (EPA, 2012). SVE (also referred to as in situ soil venting or vacuum extraction) is based on mass transfer of contaminant from the solid (sorbed) and liquid (aqueous or non-aqueous) phases into the gas phase, with subsequent collection of the gas phase ...
Gas exchange is the physical process by which gases move passively by diffusion across a surface. For example, this surface might be the air/water interface of a water body, the surface of a gas bubble in a liquid, a gas-permeable membrane, or a biological membrane that forms the boundary between an organism and its extracellular environment.
Soil chemistry is the study of the chemical characteristics of soil.Soil chemistry is affected by mineral composition, organic matter and environmental factors. In the early 1870s a consulting chemist to the Royal Agricultural Society in England, named J. Thomas Way, performed many experiments on how soils exchange ions, and is considered the father of soil chemistry. [1]
Soil aeration is the mechanism of improving the exchange of gases between the atmosphere and soil. Through soil microbial activity and plant root respiration, certain gases such as oxygen will be depleted in the soil, while others, such as carbon dioxide, will build up in the soil. [1] Lack of oxygen in the soil can impact plant growth.
Soil gases (soil atmosphere [1]) are the gases found in the air space between soil components. The spaces between the solid soil particles, if they do not contain water, are filled with air. The primary soil gases are nitrogen, carbon dioxide and oxygen. [2] Oxygen is critical because it allows for respiration of both plant roots and soil ...
Cation-exchange capacity (CEC) is a measure of how many cations can be retained on soil particle surfaces. [1] Negative charges on the surfaces of soil particles bind positively-charged atoms or molecules (cations), but allow these to exchange with other positively charged particles in the surrounding soil water. [ 2 ]
a) top soil and colluvium b) mature residual soil c) young residual soil d) weathered rock Soil deposits are affected by the mechanism of transport and deposition to their location. Soils that are not transported are called residual soils —they exist at the same location as the rock from which they were generated.