Application of Heterogenous Catalysis with TiO2 Photo Irradiated by Sunlight and Latter Activated Sludge System for the Reduction of Vinasse Organic Load

Abstract

Vinasse is the main residue generated during alcohol, sugar and blue rum production by fermentation process. This residue is effluent that could cause serious environmental pollution due to high organic load when is not treated adequately. The aim of this work consists of evaluating the efficiency and application of heterogeneous photocatalysis with TiO 2 , followed by a biological treatment (activated sludge system) to reduce organic load in the referred effluent. Complete factorial designs indicated the best experimental conditions subsequent to photacatalytic and biological treatments providing a reduction of non-purgeable organic carbon (NPOC) as a variable response. After the photocatalytic process, the sample from the best experiment condition was treated by a biological process in order to verify the degradation efficiency of the effluent organic matter studied according to the hybrid system (Advanced Oxidation Process-Activated Sludge System). This system, which presented more efficiency, had a photochemical treatment of 180 minutes carried out in aerated solutions, pH 9 and effluent in natura, while the biological treatment was performed at pH 8 and sludge concentration of 5 gL -1 . The reduction of biochemical oxygen demand (BOD) was >80%. Load the percolation until underground waters, causing an incompatible salubrity for human and animal feeding [7,8].The purpose of this work consisted in evaluating both the efficiency and the application of heterogeneous photo-

The Application of a Surface Response Methodology in the Solar/UV-Induced Degradation of Dairy Wastewater Using Immobilized ZnO as a Semiconductor

“…A new experiment was conducted with the optimized parameters from this study and the ones found in [10], that is, pH of 8.0, ZnO coating thickness of 100 m, reaction time of 3 h, effluent concentration in natura, average radiation of 584.0 W/cm 2 , reaction temperature of 31 ∘ C, and average evaporation rate of 0.17 L/h. The TOC percentage removal was of 32% as obtained by [8,12,13], though the authors employed TiO 2 with lower organic load.…”

“…The immobilization of ZnO particles was carried out by the application of a coating containing the photocatalyst [8] by DuPont do Brasil S.A., in Guarulhos, Sao Paulo. Two identical 800 × 250 mm stainless steel plates with an area of 200 cm 2 were used each with a different thickness (50 and 100 m).…”

“…Two identical 800 × 250 mm stainless steel plates with an area of 200 cm 2 were used each with a different thickness (50 and 100 m). The coating containing ZnO was diluted until obtaining a sliding viscosity as described in [8]. Difference in thickness was obtained by applying an extra layer of the prepared ZnO paint to the 100 m plate.…”

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“…Quanto menor a quantidade de pigmento, maior a espessura requerida para se ter a massa desejada (no caso, 0,025 ou 0,05 g cm -²) e quanto maior a quantidade de pigmento, menor a espessura. Desta forma, foram realizados cálculos para a determinação da espessura ideal do filme, formado com 18 % de titânio e o teor de pigmento desejado dentro de uma área de 1 cm² (Carrocci et al, 2012). Conforme análises realizadas na própria DuPont, o filme da placa utilizada contendo anatase apresentou espessura variando de 55 a 65 µm.…”

Recovery of an agro-industrial vinasse by adsorption on different wood materials: Parametric study at laboratory scale

“…Agro-food industrial processes lead to large amounts of by-product as vinasse (Carrocci et al 2012;Christofoletti et al 2013). Vinasse is generally used as an additive for animal feed because it contains a large fraction of organics (proteins, pectins, polyphenols, and colored compounds) and as a fertilizer because its mineral composition is rich in NPK elements.…”