Photodecomposition of carbaryl in the presence of silver-doped zeolite Y and Suwannee River natural organic matter.
The synthesis and characterization of a novel catalyst for the photodecomposition of carbaryl (1-naphthyl, N-methylcarbamate) is reported. In the absence of a catalyst, but in the presence of UV light a 30 ppm solution of carbaryl decomposes with a first-order rate constant of (5.6 +/- 0.3) x 10(-5) s(-1) (298 K) and a quantum efficiency of 4.8 x 10(-3) molecules/photon. In the presence of the Ag-zeolite Y catalyst with 2.42% Ag by weight, the photodecomposition rate becomes 80 times faster. The addition of Suwannee River natural organic matter (NOM), which can inactivate photocatalysts, has a minimal effect on this system. In the presence of three different concentrations of NOM and 30 ppm carbaryl, our results indicate that the NOM increases or decreases the catalytic photodecomposition rate by only a factor of 3 at most.
Kanan
Marsha C
MC
Department of Chemistry and Laboratory for Surface Science & Technology, University of Maine, Orono, Maine 04469, USA.
Kanan
Sofian M
SM
Austin
Rachel N
RN
Patterson
Howard H
HH
D012721:Carbaryl / Q000737:chemistry / Q000528:radiation effects; D002384:Catalysis; D004787:Environmental Pollution / Q000517:prevention & control*; D009930:Organic Chemicals / Q000737:chemistry; D010777:Photochemistry; D012834:Silver / Q000737:chemistry*; D014466:Ultraviolet Rays; D017641:Zeolites / Q000737:chemistry*
D009930:Organic Chemicals; D017641:Zeolites; D012834:Silver; D012721:Carbaryl