title: Carbofuran removal in continuous-photocatalytic reactor: Reactor optimization, rate-constant determination and carbofuran degradation pathway analysis.
abstract: Carbofuran (CBF) removal in a continuous-flow photocatalytic reactor with granular activated carbon supported titanium dioxide (GAC-TiO2) catalyst was investigated. The effects of feed flow rate, TiO2concentration and addition of supplementary oxidants on CBF removal were investigated. The central composite design (CCD) was used to design the experiments and to estimate the effects of feed flow rate and TiO2concentration on CBF removal. The outcome of CCD experiments demonstrated that reactor performance was influenced mainly by feed flow rate compared to TiO2concentration. A second-order polynomial model developed based on CCD experiments fitted the experimental data with good correlation (R2∼ 0.964). The addition of 1 mL min-1hydrogen peroxide has shown complete CBF degradation and 76% chemical oxygen demand removal under the following operating conditions of CBF ∼50 mg L-1, TiO2∼5 mg L-1and feed flow rate ∼82.5 mL min-1. Rate constant of the photodegradation process was also calculated by applying the kinetic data in pseudo-first-order kinetics. Four major degradation intermediates of CBF were identified using GC-MS analysis. As a whole, the reactor system and GAC-TiO2catalyst used could be constructive in cost-effective CBF removal with no impact to receiving environment through getaway of photocatalyst.
authors.affiliation: a Department of Chemical Engineering , National Institute of Technology Calicut , Kerala , India.
authors.forename: M A
authors.initials: MA
authors.lastname: Vishnuganth
authors.affiliation: b School of Infrastructure , Indian Institute of Technology , Bhubaneswar , Odisha , India.
authors.forename: Neelancherry
authors.initials: N
authors.lastname: Remya
authors.affiliation: c Department of Civil Engineering , Indian Institute of Technology Madras , Tamil Nadu , India.
authors.forename: Mathava
authors.initials: M
authors.lastname: Kumar
authors.affiliation: a Department of Chemical Engineering , National Institute of Technology Calicut , Kerala , India.
authors.forename: N
authors.initials: N
authors.lastname: Selvaraju
mesh_terms: D057919:Biological Oxygen Demand Analysis; D002235:Carbofuran / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D002384:Catalysis; D002606:Charcoal; D004785:Environmental Pollutants / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D004867:Equipment Design; D008401:Gas Chromatography-Mass Spectrometry; D006861:Hydrogen Peroxide / Q000737:chemistry; D007700:Kinetics; D058433:Photobioreactors; D010782:Photolysis; D014025:Titanium / Q000737:chemistry; D014466:Ultraviolet Rays
chemical_list: D004785:Environmental Pollutants; C009495:titanium dioxide; D002606:Charcoal; D006861:Hydrogen Peroxide; D014025:Titanium; D002235:Carbofuran
keywords: Carbofuran; GAC supported TiO2; central composite design; photocatalysis; pseudo-first-order reaction model