Submitted to: Elsevier
Publication Type: Review Article
Publication Acceptance Date: October 6, 2005
Publication Date: October 1, 2006
Citation: Goldberg, S.R., Suarez, D.L. 2006. Prediction of anion adsorption and transport in soil systems using the constant capacitance model. In: J. Lutzenkirchen (ed.) Surface complexation modeling. Interface Science and Technology series, Elsevier, Amsterdam, Volume 11 p: 491-517. Technical Abstract: Adsorption of trace elements on soil surfaces is an important process in managing trace element toxicity or deficiency as well as concentrations in discharge waters. Increasing demands for high quality water in arid and semi arid regions are coupled with environmental concerns and constraints of the discharge of agricultural drainage waters. A major part of these environmental concerns in the southwestern United States and elsewhere are related to discharge of oxyanions Se, As and B. Agriculture must utilize low quality waters for irrigation in addition to drainage waters. The high concentrations of oxyanions may also adversely affect plant growth. Availability of trace elements to plants is affected by a variety of factors including soil pH, soil texture, soil moisture, temperature, oxide content, carbonate, content, and clay mineralogy. The adsorbing surfaces in soils are oxides, clay minerals, calcite, and organic matter. Quantification of soil solution trace element concentrations requires the characterization of trace element adsorption reactions on soil surfaces. There are currently restrictions on discharge of oxyanions from drainage waters into many surface streams and rivers in the southwestern US. There is a clear need to predict oxyanion concentrations in drainage waters including how changes in soil management will impact the subsurface adsorption and transport. In addition, water quality criteria for irrigation currently neglect the impact of adsorption to alter the soil solution composition, thus many drainage waters are considered unsuitable for reuse. As will be demonstrated, management options can utilize the non-steady state dynamics of adsorption and desorption.