Photodecomposition of Carbaryl in the Presence of Silver-Doped Zeolite Y and Suwannee River Natural Organic Matter

• Published in: Environmental science & technology 2003-05, Vol.37 (10), p.2280-2285
• Main Authors: Kanan, Marsha C, Kanan, Sofian M, Austin, Rachel N, Patterson, Howard H
• Format: Article
• Language: English
• Subjects: Applied sciences; Atoms & subatomic particles; Biological and physicochemical phenomena; Carbaryl - chemistry; Carbaryl - radiation effects; Catalysis; Decomposition; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environmental Pollution - prevention & control; Exact sciences and technology; Natural water pollution; Organic Chemicals - chemistry; Organic chemistry; Photochemistry; Pollution; Pollution, environment geology; Rivers; Silver; Silver - chemistry; Ultraviolet Rays; Water treatment and pollution; Zeolites; Zeolites - chemistry
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es026136+

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) × 10-5 s-1 (298 K) and a quantum efficiency of 4.8 × 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.