TY - JOUR
T1 - Kinetics and mechanism of abiotic decomposition of malodorous dimethyl disulfide under dark, oxic conditions
AU - Buchshtav, Tamir
AU - Amrani, Alon
AU - Kamyshny, Alexey
N1 - Publisher Copyright:
© 2019 CSIRO.
PY - 2019
Y1 - 2019
N2 - The presence of malodorous dimethyl polysulfides (DMPSs) has been documented in limnic systems as well as in tap water distribution systems. These compounds compromise the quality of drinking water. In this work, we studied kinetics and mechanisms of the decomposition reactions of the most abundant and stable DMPS, dimethyl disulfide (DMDS), in aqueous solutions in the presence of oxygen and absence of light. It was found that DMDS reacts with a hydroxyl ion and its decomposition leads to the formation of methyl mercaptan and other products. The decomposition reaction is of the first order with respect to both the concentration of DMDS and the activity of the hydroxyl ion, with an activation energy of 90 ± 8 kJ mol -1 . The half-life of DMDS under abiotic, dark, oxic conditions was observed to vary from thousands to hundreds of thousands of years depending on the pH and temperature. These results indicate that DMDS is decomposed by other chemical, photochemical and microbially-mediated pathways.
AB - The presence of malodorous dimethyl polysulfides (DMPSs) has been documented in limnic systems as well as in tap water distribution systems. These compounds compromise the quality of drinking water. In this work, we studied kinetics and mechanisms of the decomposition reactions of the most abundant and stable DMPS, dimethyl disulfide (DMDS), in aqueous solutions in the presence of oxygen and absence of light. It was found that DMDS reacts with a hydroxyl ion and its decomposition leads to the formation of methyl mercaptan and other products. The decomposition reaction is of the first order with respect to both the concentration of DMDS and the activity of the hydroxyl ion, with an activation energy of 90 ± 8 kJ mol -1 . The half-life of DMDS under abiotic, dark, oxic conditions was observed to vary from thousands to hundreds of thousands of years depending on the pH and temperature. These results indicate that DMDS is decomposed by other chemical, photochemical and microbially-mediated pathways.
KW - decomposition kinetics
KW - dimethyl polysulfides
KW - reduced sulfur compounds
KW - volatile organic sulfur compounds
UR - http://www.scopus.com/inward/record.url?scp=85062968472&partnerID=8YFLogxK
U2 - 10.1071/EN18206
DO - 10.1071/EN18206
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AN - SCOPUS:85062968472
SN - 1448-2517
VL - 16
SP - 165
EP - 170
JO - Environmental Chemistry
JF - Environmental Chemistry
IS - 3
ER -
