Jarvis, Nicholas
- Department of Soil and Environment, Swedish University of Agricultural Sciences
Abstract
Models used to assess leaching risks generally use organic carbon partition coefficient (k(OC)) values derived from batch experiments on topsoil samples to estimate pesticide sorption in subsoils of much smaller organic carbon contents. This can introduce significant errors in leaching risk calculations, because inorganic sorbents can play an important role for sorption in subsoil. The objectives of the present study were therefore to summarize the available literature data on pesticide sorption in subsoils and to test whether a simple alternative model could improve on the standard k(OC) approach used in risk assessment models for pesticide leaching. This model describes the sorption constant as a power law function of the organic carbon content. A database with the results of batch sorption experiments was collated from published studies that emphasized measurements in subsoils. This database contains 1029 data entries from 36 published studies with data for 29 active substances (11 nonionic compounds, 10 weak acids, 6 weak bases, one cation, and one zwitterion). The results show that whereas the constant k(OC) model proved to be an adequate model for 17 of the 63 individual datasets, the power law model gave acceptable fits (p
Keywords
Pesticides; Adsorption; Fate modeling; Leaching; Subsoil
Published in
Environmental Toxicology and Chemistry
2018, volume: 37, number: 3, pages: 755-761
Publisher: WILEY
SLU Authors
UKÄ Subject classification
Soil Science
Publication identifier
- DOI: https://doi.org/10.1002/etc.4011
Permanent link to this page (URI)
https://res.slu.se/id/publ/94372