J Agric Food Chem
Sunchon National University, Suncheon, Jeonnam 540-742, Korea.
Published: April 2003
Photocatalytic degradation of pesticides with titanium dioxide (TiO(2)) and other catalysts has shown promise as a potential water remediation method. Titanium-based powders have been used in photocatalytic degradation studies but have limitations. The objective of this study was to determine picloram degradation in water using various UV light sources and low-pressure metal organic chemical vapor deposition titanium dioxide alumina beads (TDABs) as a catalyst. A triple-annular, flow-through photoreactor was used as a degradation chamber. A picloram test solution of 50 microg/mL was introduced to the photoreactor inlet and recycled for 10 h at a flow rate of 50 mL/min. Three ultraviolet light sources were compared for their photocatalytic capacity (UV-A, UV-B, and UV-C) both with and without TDABs. TDABs were added to the photoreactor at 1.8 g/cm(3). Dark treatments with and without TDABs were included to quantify hydrolysis or adsorption. A 500-microL aliquot was taken from the test solution 14 times during the 10-h recycling period. Sampling times ranged from 0 to 600 min (10 h). These aliquots were placed in a vial and analyzed by high performance liquid chromatography equipped with a photodiode array detector. Picloram was not significantly hydrolyzed or adsorbed to TDABs during the experiment. The picloram degradation rate with UV-A and TDABs (t(1/2) = 119.5 min) was greater than the degradation rate of UV-A alone (t(1/2)=2288 min). Picloram degradation was not enhanced by the presence of TDABs with either UV-B or UV-C. This may be attributed to inadequate TDAB densities and/or poor light penetration in the photoreactor. Rapid picloram degradation occurred with both UV-B and UV-C, regardless of the presence of TDABs with mean half-lives ranging from 7 to 18 min. These rates were 8 to 16 times faster than picloram degradation using UV-A with TDABs. TDABs' greatest photocatalytic effect was with the lowest energy light source (UV-A). However, picloram degradation was not enhanced when TDABs were combined with more powerful, shorter wavelength light.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/jf026232u | DOI Listing |
PLoS One
November 2024
Department of Botany and Ecology, Institute of Biosciences, Federal University of Mato Grosso, Cuiabá, Mato Grosso, Brazil.
Many countries widely use pesticides to increase crop productivity in agriculture. However, their excessive and indiscriminate use contaminates soil and other environments and affects edaphic microbial communities. We aimed to examine how the pesticides carbofuran and picloram affect the structure and functionality of soil microbiota using cultivation-independent methods.
View Article and Find Full Text PDFEnviron Res
December 2024
UMR 7372, Centre D'Études Biologiques de Chizé, La Rochelle Université & CNRS, 79360, Villiers en Bois, France.
Intensive use of synthetic pesticides in conventional agriculture may harm non-target organisms through sublethal effects on life-history traits. Farmland birds are exposed throughout their life cycle, but the fate of non-persistent pesticide mixtures in wild birds remains unknown. In this study, we investigated changes in pesticide contamination levels in Montagu's harrier (Circus pygargus) nestlings during their growth.
View Article and Find Full Text PDFSci Rep
July 2024
Aerospace Research Institute, Ministry of Science Research and Technology, Tehran, 14665-834, Iran.
Physalis alkekengi L. is a valuable medicinal plant from the Solanaceae family and has multiple therapeutic applications. This study aimed to develop an optimized protocol for callogenesis in P.
View Article and Find Full Text PDFMolecules
January 2024
Innovation Center of Pesticide Research, Department of Applied Chemistry, College of Science, China Agricultural University, Beijing 100193, China.
Thirty-eight new 4-amino-3,5-dicholo-6-(1-indazolyl)-2-picolinic acids and 4-amino-3,5-dicholo-6-(2-indazolyl)-2-picolinic acids were designed by scaffold hopping and synthesized to discover potential herbicidal molecules. All the new compounds were tested to determine their inhibitory activities against and the root growth of five weeds. In general, the synthesized compounds exhibited excellent inhibition properties and showed good inhibitory effects on weed root growth.
View Article and Find Full Text PDFMAbs
May 2023
Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL, USA.
Camelid heavy-chain-only antibodies are a unique class of antibody that possesses only a single variable domain (termed VHH) for antigen recognition. Despite their apparent canonical mechanism of target recognition, where a single VHH domain binds a single target, an anti-caffeine VHH has been observed to possess 2:1 stoichiometry. Here, the structure of the anti-caffeine VHH/caffeine complex enabled the generation and biophysical analysis of variants that were used to better understand the role of VHH homodimerization in caffeine recognition.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!
© LitMetric 2025. All rights reserved.