title: Industrial and agroindustrial wastes: an echotechnological approach to the production of supported photocatalysts.
abstract: Agroindustrial wastes (rice husk, exhausted bark acacia, and tobacco dust) and foundry sands from the iron foundry industry were employed as a support source for photocatalysts. TiCl4 was used as the titanium precursor in the preparation of the supported photocatalysts. The solids were characterized by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), diffuse reflectance spectroscopy over the ultraviolet range (DRS-UV), X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), nitrogen adsorption-desorption at -196 °C and zeta potential (ZP) measurements. The systems were evaluated for the photodegradation of rhodamine B (RhB). Among the tested systems, the highest percentage of dye degradation was reached by the catalyst prepared with foundry sand supports, with values of 65% under ultraviolet and 39% under visible radiation, whereas under the same conditions, the catalyst prepared with rice husk showed the best photocatalytic performance among the samples prepared with agroindustrial wastes with values of 43% under ultraviolet and 38% under visible radiation. Strong Spearman's correlations among the photocatalytic activity, the zeta potential (ζp>0.900) and the band gap energy (ζp>0.895) were observed. Exploratory tests with tap water samples revealed that the system may be sensitive to other analytes present in these environmental samples.
authors.affiliation: Departamento de Engenharia Química, Universidade Federal do Rio Grande do Sul, Rua Eng. Luis Englert s/n, 90040-040 Porto Alegre, RS, Brazil.
authors.forename: William Leonardo
authors.initials: WL
authors.lastname: da Silva
authors.affiliation: Departamento de Engenharia Química, Universidade Federal do Rio Grande do Sul, Rua Eng. Luis Englert s/n, 90040-040 Porto Alegre, RS, Brazil.
authors.forename: Marla Azário
authors.initials: MA
authors.lastname: Lansarin
authors.affiliation: Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves n° 9500, 91501-970 Porto Alegre, Brazil E-mail: jhzds@iq.ufrgs.br.
authors.forename: João H Z
authors.initials: JH
authors.lastname: dos Santos
mesh_terms: D000383:Agriculture; D002384:Catalysis; D007220:Industrial Waste; D007501:Iron; D008027:Light; D019684:Magnoliopsida; D008669:Metallurgy; D008855:Microscopy, Electron, Scanning; D009584:Nitrogen; D010782:Photolysis; D012235:Rhodamines; D053838:Scattering, Small Angle; D013052:Spectrometry, X-Ray Emission; D014025:Titanium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification; D014961:X-Ray Diffraction
chemical_list: D007220:Industrial Waste; D012235:Rhodamines; D014874:Water Pollutants, Chemical; C025096:titanium tetrachloride; D014025:Titanium; D007501:Iron; C029773:rhodamine B; D009584:Nitrogen