This three volume report describes the conceptualization, measurement and use of the partition (or distribution) coefficient, Kd, parameter. It describes the geochemical aqueous solution and sorbent properties that are most important in controlling adsorption/retardation behavior of selected contaminants.

These technical reports are designed for EPA and other organizations who are responsible for site remediation and waste management decisions. The three volume report was a collaborative effort of EPA's Office of Emergency and Remedial Response, Office of Radiation and Indoor Air, and the Department of Energy's Office of Environmental Restoration.

Understanding Variation in Partition Coefficient, Kd, Values: Volume I (pdf) (2.58 MB, 402-R-99-004a)
Volume I discusses the technical issues associated with the measurement of Kd values and its use in formulating the retardation factor, Rf. The Kd concept and methods for measurement of Kd values are discussed in detail in Volume I.

Understanding Variation in Partition Coefficient, Kd, Values: Volume II (pdf) (2.49 MB, 402-R-99-004b)
Volume II provides a ""thumb-nail sketch"" of the key geochemical processes affecting the sorption of selected inorganic contaminants, and a summary of Kd values given in the literature for these contaminants under oxidizing conditions. Important aqueous speciation, (co)precipitation/dissolution, and adsorption reactions are discussed for each contaminant.

Understanding Variation in Partition Coefficient, Kd, Values: Volume III (pdf) (837.92 KB, 402-R-04-002c)
Volume III describes: (1) the conceptualization, measurement, and use of the partition coefficient parameter; and (2) the geochemical aqueous solution and sorbent properties that are most important in controlling adsorption/retardation behavior of selected contaminants.