Alternatives for the determination of the soil adsorption coefficient, KOC, of non-ionicorganic compounds - a review

The determination of the soil adsorption behaviour of an environmental chemical is very important to the evaluation of potential dangers for man and nature. One of the major problems for European regulators working in the field of environmental protection and risk assessment is the lack of complete and comparable soil sorption data, e.g. K_oc values. The large number of existing chemicals makes it necessary to develop and apply fast methods as an alternative to classical batch or column studies. Based on this context numerous approaches to estimate K_oc have been published during the past two decades.

In this paper more than 200 existing relationships for K_oc estimations have been reviewed and divided into four categories. Regression equations for the most important classes of non-ionic organic environmental chemicals able to estimate soil adsorption coefficients are summarised, and the advantages and drawbacks of the different approaches are discussed briefly.

Due to the fact that a broad application of the proposed approaches is limited by the quality and comparability of the underlying experimental K_oc values reference soils are postulated to create a common basis for the comparison of soil adsorption coefficients.