Catalytic ozonation of metolachlor under continuous operation using nanocarbon materials grown on a ceramic monolith

• Published in: Journal of hazardous materials 2012-11, Vol.239-240, p.249-256
• Main Authors: Restivo, J., Órfão, J.J.M., Armenise, S., Garcia-Bordejé, E., Pereira, M.F.R.
• Format: Article
• Language: English
• Subjects: Acetamides - chemistry; Acetamides - toxicity; Aliivibrio fischeri - metabolism; byproducts; carbon; Carbon nanomaterials; carbon nanotubes; Catalysis; catalysts; Catalytic ozonation; ceramics; Ceramics - chemistry; combs (social insects); Emerging organic micropollutants; Herbicides - chemistry; Herbicides - toxicity; Luminescence; Metolachlor; mineralization; Monolith; nanofibers; Nanofibers - chemistry; Nanotubes, Carbon - chemistry; Oxidants - chemistry; ozonation; Ozone - chemistry; toxicity; Vibrio fischeri; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - toxicity; Water Purification - methods
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2012.08.073

► Catalytic ozonation of metolachlor was compared to single ozonation. ► Carbon nanomaterials, in powder form or grown on a macrostructure, were used. ► Higher mineralization and lower toxicity were attained in catalytic ozonation. ► Formation of organic acids and release of inorganic ions were evaluated. ► Macrostructured catalysts have potential applications in practical ozonation processes. The catalytic ozonation of the herbicide metolachlor (MTLC) was tested using carbon nanomaterials as catalysts. Multiwalled carbon nanotubes were used in semi-batch experiments and carbon nanofibres grown on a honeycomb cordierite monolith were tested in continuous experiments. The application of the carbon catalyst was shown to improve the mineralization degree of MTLC and to decrease the toxicity of the solution subject to ozonation. Degradation by-products were also followed in order to compare the two processes. The application of the carbon coated monolith to the continuous ozonation process was shown to have potential as it improved the TOC removal from 5% to 35% and decreased the inhibition of luminescent activity of Vibrio Fischeri from 25% to 12%.