An investigation into advanced oxidation of three chlorophenoxy pesticides in surface water

摘要

The performance of Fenton’s reagent in removing 2,4-D, MCPA and mecoprop from surfacenwater has been evaluated here. Initial trials were undertaken at a pesticide concentration ofn4.5 ￡ 1025 mol l21 in deionised water at pH 3 and two different stoichiometric ratios ofnpesticide: Fe(II): H2O2 (1:1:10, 1:10:10) were evaluated. At the 1:1:10 ratio, ,10 minutes werenrequired to achieve a 50% removal of the pesticide. At the higher ratio the removal achievednafter 1 minute, was .90%. Subsequent experiments studied the performance of Fentonn(4.5 ￡ 1024 mol l21 Fe(II): 4.5 ￡ 1024 mol l21 H2O2) in surface water spiked with pesticides andnthe impact of pH on the rate and degree of pesticide degradation was investigated. The removalnwas significantly improved at pH 3 in comparison to pH 6.5. The effect of Fenton on DOC removalnfrom surface water was followed. Experiments investigated the performance of Fenton atnpesticide concentrations of 7.5 ￡ 1029 mol l21 in surface water. Fenton was shown to benan effective treatment for removing low levels of pesticides from surface waters at pH 3 & 4.