Absolute kinetics and reaction efficiencies of hydroxyl-radical-induced degradation of methyl isothiocyanate (MITC) in different quality waters

作者：Swancutt Katy L; Dail Michelle K; Mezyk Stephen P^*; Ishida Kenneth P

来源：Chemosphere, 2010, 81(3): 339-344.

DOI：10.1016/j.chemosphere.2010.07.027

• Methyl isothiocyanate
• MITC
• Free radicals
• Kinetics
• Degradation efficiencies

Methyl isothiocyanate (MITC), a toxic and corrosive skin and respiratory irritant, is a common soil fumigant byproduct which has become an atmospheric, aqueous, and soil contaminant The work described here examines the degradation and potential removal of MITC from contaminated waters via free radical reactions We have measured the oxidizing hydroxyl radical (OH) reaction rate constant with MITC overt range of temperatures relevant to wastewater treatment conditions, determining a room temperature value of (5 69 +/- 0 56) x 10(8) M(-1) s(-1) and a corresponding Airhenius activation energy of 12.90 +/- 0 82 kJ mol(-1) Hydroxyl radical reaction efficiencies with MITC in pure water, an associated matrix of model real-world waters, and a reverse osmosis permeate water have also been determined While solutions containing these constituents had significantly decreased MITC removal efficiencies (5.5-14 7%) as compared to pure water (54 4 +/- 3 4%). relative rate calculation corrections showed that the OH radical efficiencies for solutions containing DOM were the same as in pure water However,

• 出版日期2010-9