Effects of combined and sequential addition of dual oxidants (H 2O2/S2O82-) on the aqueous carbofuran photodegradation

Wei Chu, Tim K. Lau, Sai C. Fung

Research output: Journal article publicationJournal articleAcademic researchpeer-review

62 Citations (Scopus)

Abstract

Carbofuran (2,3-dihydro-2,2-dimethylbenzofuran-7-yl methylcarbamate) (CBF) is a widely used insecticide. Traditional methods like hydrolysis and direct photolysis cannot remove CBF effectively. In this study, the photodecay of 0.1 mM CBF in UV/H2O2, UV/S2O82-, and UV/H2O2/S2O82- and sequential addition of a second oxidant were studied under UV light at 254 nm. The degradations of CBF follow pseudo-first-order decay kinetics. Direct photolysis was slow, but the corresponding degradation rate was increased with the addition of hydrogen peroxide (H2O2) or potassium peroxydisulfate (K2S2O8). In the UV/H2O2 reaction, the optimum reaction rate was 0.9841 min-1 at 10 mM H2O2 (pH 7); however, retardation is observed if H2O2 is overdosed. Such retardation is not observed in the UV/S2O82- system, but a nonlinear increment of removal efficiency is identified. The UV/H2O2/S2O82- process on the other hand shows the best performance in CBF degradation, but it has a less effective mineralization than that of the sole UV/S2O 82- reaction.
Original languageEnglish
Pages (from-to)10047-10052
Number of pages6
JournalJournal of Agricultural and Food Chemistry
Volume54
Issue number26
DOIs
Publication statusPublished - 27 Dec 2006

Keywords

  • Advanced oxidation process
  • Carbofuran
  • Endocrine disruptor
  • Mineralization
  • Photolysis

ASJC Scopus subject areas

  • Chemistry(all)
  • Agricultural and Biological Sciences(all)

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