title: Solar photocatalytic degradation of reactive blue 4 using a Fresnel lens.
abstract: The heterogeneous photocatalytic degradation of reactive blue 4 dye (RB4) solutions under Fenton reagent and TiO(2) assisted by concentrated solar light irradiation using a Fresnel lens has been studied. Multivariate experimental design was applied to study the kinetic process. The efficiency of photocatalytic degradation was determined from the analysis of color and total organic carbon (TOC) removal. Factorial experimental design allowed to determine the influence of four parameters (pH and initial concentrations of TiO(2), Fe(II) and H(2)O(2)) on the value of the decoloration kinetic rate constant. Experimental data were fitted using neural networks (NNs). The mathematical model reproduces experimental data within 86% of confidence and allows the simulation of the process for any value of parameters in the experimental range studied. Also, a measure of the saliency of the input variables was made based upon the connection weights of the neural networks, allowing the analysis of the relative relevance of each variable with respect to the others. Results showed that acidic pHs (pH=3.6) are preferred for the complete dye decoloration. The optimum catalyst concentration is 1.2g TiO(2)/l. The use of a low cost catalyst and its activation using a Fresnel lens to concentrate solar energy significantly accelerates the degradation process when compared with direct solar radiation alone and can offer an economical and practical alternative for the destruction of environmental organic compounds.
authors.affiliation: Department of Chemical Engineering, Escuela Técnica Superior de Ingenieros Industriales, University of Castilla-La Mancha, Avda. Camilo José Cela 3, 13071 Ciudad Real, Spain. antonio.duran@uclm.es
authors.forename: A
authors.initials: A
authors.lastname: Durán
authors.forename: J M
authors.initials: JM
authors.lastname: Monteagudo
mesh_terms: D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry; D010777:Photochemistry / Q000295:instrumentation / Q000379:methods*; D013472:Sunlight; D014227:Triazines / Q000737:chemistry* / Q000528:radiation effects; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000528:radiation effects; D018508:Water Purification / Q000379:methods
chemical_list: D014227:Triazines; D014874:Water Pollutants, Chemical; C036598:procion blue MX-R; D006861:Hydrogen Peroxide; D007501:Iron