RESUMO
The present article reports the treatment of resorcinol using a catalytic wet peroxidation (CWPO) process in the presence of copper impregnated granular activated carbon (Cu/GAC) with a bench-scale batch reactor. The typical physico-chemical properties of synthesized catalyst were characterized with different equipment and methods. 90% resorcinol removal and 81% of TOC removal was achieved at optimum conditions (pHâ¯=â¯6, the stoichiometric ratio of H2O2/resorcinolâ¯=â¯1.2, catalyst doseâ¯=â¯0.5â¯g/L, initial concentration of resorcinolâ¯=â¯100â¯mg/L, temperatureâ¯=â¯70⯰C and time tâ¯=â¯4â¯h). Fourier-transform infrared spectroscopy (FTIR) measurements revealed that GAC posses various conjugated hydrocarbon groups including aromatic hydrocarbons, carboxylic groups, carboxyl and carbonate. Cu/GAC catalyst has a surface smoother than that of pristine GAC. At neutral or natural pH (â¼6.4) of resorcinol, CWPO of resorcinol is favorable by Cu/GAC catalyst. Catalyst stability study revealed that Cu/GAC sustain its catalytic reactivity to over 76% in the five cycles without any regeneration. The thermogravimetric analysis confirmed that 350⯰C temperature found to be optimum for calcination of Cu/GAC without any major losses. The mineralization mechanism was proposed based on intermediates identified during CWPO reaction.
Assuntos
Cobre/química , Resorcinóis/química , Poluentes Químicos da Água/química , Adsorção , Carbono , Carvão Vegetal , Peróxido de Hidrogênio , OxirreduçãoRESUMO
Cerium supported SBA-15 (Ce/SBA-15) was synthesized by two-step synthesis method in acidic medium. It was further characterized by various characterization techniques such as X-ray diffraction, field-emission scanning electron microscopy, Fourier transform infrared spectroscopy and N2 adsorption-desorption pore size distribution analysis. The Ce/SBA-15 showed highly ordered meso-structure with pore diameter≈70-100Ǻ and pore volume≈0.025cm(3)/g. Ce/SBA-15 was further evaluated as a catalyst for the oxidation of highly toxic and non-biodegradable material, pyridine, by catalytic wet-peroxidation method. The effects of various operating parameters such as catalyst dose (0.5-6g/l), stoichiometric ratio of H2O2/pyridine (1-6), initial pyridine concentration (50-800mg/l) and temperature (313-358K) have been evaluated and optimized. Ce/SBA-15 showed stable performance during reuse for six cycles with negligible cerium leaching. Kinetic and thermodynamic parameters and operation cost have also been determined.