Papers Published

1. Shemer, Hilla and Sharpless, Charles M. and Elovitz, Michael S. and Linden, Karl G., Relative rate constants of contaminant candidate list pesticides with hydroxyl radicals, Environmental Science and Technology, vol. 40 no. 14 (2006), pp. 4460 - 4466 [es0602602] .
   (last updated on 2007/04/09)

   Abstract:
   The objective of this study was to establish the relative rate constants for the reactions of selected pesticides (linuron, diuron, prometon, terbacil, diazinon, dyfonate, terbufos, and disulfoton) listed on the U.S. EPA Contaminant Candidate List with UV and hydroxyl radicals (·OH). Batch experiments were conducted in phosphate buffered solution at pH 7. All pesticides were found to be very reactive toward ·OH as indicated by rate constant values above 10⁹ M^-1 s^-1. Using molinate as a reference compound, k_OH ranged from 2.7 × 10⁹ to 12.0 × 10⁹ M^-1 s^-1 for the contaminants while slightly higher values from 2.9 × 10⁹ to 14.3 × 10⁹ M^-1 s^-1 were obtained using nitrobenzene as a reference compound. A method was established that accounts for direct photolysis when calculating k_OH using UV/H₂O₂ process for compounds which degrade significantly by a direct photolysis mechanism. © 2006 American Chemical Society.

   Keywords:
   Rate constants;pH effects;Photolysis;Solutions;