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United States Department of Agriculture

Agricultural Research Service

Research Project: THERMOCHEMICAL PROCESSING OF AGRICULTURAL WASTES TO VALUE-ADDED PRODUCTS AND BIOENERGY Title: Sorption of organophosphate and triazine agrochemicals on biochars and soils

Author
item Uchimiya, Sophie

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 17, 2012
Publication Date: N/A

Technical Abstract: Biochars are known to strongly sorb polar and nonpolar organic compounds, and biochar soil amendment can have counteracting impacts on the efficacy of, and runoff contamination by agrochemicals. This study investigated the sorption-desorption isotherms and kinetics of triazine (deisopropylatrazine) and organophosphorus (malathion, parathion, diazinon) pesticides on various soil types ranging from sandy acidic to clayey alkaline, as well as unactivated and activated biochars having a wide range of BET surface areas. Regardless of feedstock and pyrolysis condition, an increase in Freundlich distribution coefficient and isotherm nonlinearity was observed for deisopropylatrazine as a function of BET surface area at low surface coverage. Sorption of deisopropylatrazine was strongly hysteric on biochars and soils, and competition was observed with CuII in binary-solute experiments. Fate of organophosphate pesticides were strongly influenced by their stability, and the following general increasing trend was observed for the sorption on different soil samples: deisopropylatrazine<malathion<diazinon<parathion.

Last Modified: 12/21/2014
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