title: Monopersulfate photocatalysis under 365 nm radiation. Direct oxidation and monopersulfate promoted photocatalysis of the herbicide tembotrione.
abstract: Oxone(®) (potassium monopersulfate, MPS) has been used to oxidize the herbicide tembotrione in aqueous solution. Tembotrione elimination kinetics by MPS direct oxidation has been studied. The influence of the main operating variables affecting the process (MPS concentration, temperature and pH) has been evaluated. The process follows 2/3 and first orders in MPS and tembotrione concentrations, respectively. Optimal pH is located around circumneutral conditions. MPS decomposition in the presence of 365 nm UVA radiation and titanium dioxide has also been studied. A kinetic mechanism that simulates MPS decomposition has been proposed, showing the positive effect of titania load and MPS concentration. The system MPS/UVA/TiO2 significantly improves tembotrione and mineralization rate abatement if compared to runs conducted in the absence of MPS. Tembotrione total abatement was achieved in 20 min when 0.05 g L(-1) of titania and 10(-4) M of Oxone(®) were used. TOC conversion was roughly 70% in 90 min under similar operating conditions. An experimental design (Plackett-Burman) has been considered to study the influence of the main variables affecting tembotrione photocatalytic oxidation promoted by MPS.
authors.affiliation: Department of Chemical Engineering and Physical Chemistry, University of Extremadura, Av. Elvas s/n, 06006, Badajoz, Spain; University Institute of Water Research, Climate Change and Sustainability, IACYS. University of Extremadura, Av. Elvas s/n, 06006, Badajoz, Spain. Electronic address: rrodrig@unex.es.
authors.forename: Rafael R
authors.initials: RR
authors.lastname: Solís
authors.affiliation: Department of Chemical Engineering and Physical Chemistry, University of Extremadura, Av. Elvas s/n, 06006, Badajoz, Spain; University Institute of Water Research, Climate Change and Sustainability, IACYS. University of Extremadura, Av. Elvas s/n, 06006, Badajoz, Spain.
authors.forename: F Javier
authors.initials: FJ
authors.lastname: Rivas
authors.affiliation: Department of Chemical Engineering and Physical Chemistry, University of Extremadura, Av. Elvas s/n, 06006, Badajoz, Spain.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Tierno
mesh_terms: D002384:Catalysis; D003512:Cyclohexanones / Q000737:chemistry*; D004867:Equipment Design; D006540:Herbicides / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010084:Oxidation-Reduction; D055668:Photochemical Processes; D017680:Potassium Compounds / Q000737:chemistry*; D013431:Sulfates / Q000737:chemistry*; D013450:Sulfones / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry; D014466:Ultraviolet Rays; D014865:Waste Disposal, Fluid / Q000295:instrumentation / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry
chemical_list: D003512:Cyclohexanones; D006540:Herbicides; D017680:Potassium Compounds; D013431:Sulfates; D013450:Sulfones; D014874:Water Pollutants, Chemical; C009495:titanium dioxide; C009007:potassium persulfate; D014025:Titanium; C585552:tembotrione
keywords: Monopersulfate; Oxone; Photocatalysis; Tembotrione; UVA radiation