Treatment of Organophosphate Pesticides on the EPAContaminant Candidate List Using Ozonation

摘要

Four organophosphate pesticides, I.e. diazinon, dyfonate (fonofos),rnterbufos and disulfoton, which are on the EPA drinking waterrnContaminant Candidate List, were screened for their relative reactivityrnagainst the ozonation process using batch-scale experiments at pH 8.2.rnOzone kinetics followed first-order decay, with a decay constant ofrn(1.14 ± 0.20)*10-3 sec-1 -at initial ozone concentration of 2.3-2.4 mg/L.rnRates of pesticides degradation were in the order of: disulfoton >～rnterbufos > dyfonate > diazinon. The relative decay rates werernassociated with the number and location of sulfur molecules on thernpesticide structures. The use of O3/H2O2 AOP seems unnecessary forrnthe treatment of terbufos and disulfoton but is necessary for thernefficient removal of diazinon and dyfonate.