Use of Fenton's Reagent for Removal of Pesticides from Industrial Wastewater

The process of pesticide (γ-HCH and inactive isomers α- and β-HCH, DDT, DMDT, fenitrothion and chlorfenvinphos) removal from industrial wastewater using Fenton's reaction has been analysed. Most of the pesticides were completely degraded at H₂O₂ concentration of 2.5 g/dm³; however, only at 5 g/dm³ were all the examined pesticides completely removed and the results repeatable. The most effective process was for fenitrothion (from 98.5 to 100%) and chlorfenvinphos (from 97.1 to 100%), whereas organochlorine pesticides were removed with efficiency of more than 90%. The optimum ratio of [Fe²⁺] to [H₂O₂] was from 1:3 to 1:2 while the optimum pH was from 3.0 to 3.5. Tests based upon a bioluminescent bacteria Vibrio fischeri NRRL B-11177, at optimized Fenton's reaction parameters, show the reduction of toxicity to non-toxic levels.