Construção e estudos de perfomance de um reator fotoquímico tipo CPC ("Compound Parabolic Concentrator")

Abstract

Recebido em 13/1/04; aceito em 27/1/05; publicado na web em 30/6/05 CONSTRUCTION AND PERFORMANCE STUDIES OF A CPC TYPE PHOTOCHEMICAL REACTOR. A CPC (Compound Parabolic Concentrator) reactor was projected and constructed aiming to promote the degradation of the organic matter present in considerable volumes of aqueous effluents, under the action of solar radiation. The essays were done using a model effluent which consists of a mixture of fragments of a sodium salt of lignosulphonic acid possessing a mean molecular weigth of 52,000 Daltons, and a real effluent, from a chip board industry. The volume of effluent in each test was about 50 L. The tests involved heterogeneous (TiO 2 P25 Degussa and formulations made from the association of TiO 2 with a photosensitiser), and homogeneous (thermal and photochemical Fenton reactions) catalysis of the effluents. The results demonstrate the viability of application of this kind of reactor even when the load of organic pollutants is high.

Potential Applications for Solar Photocatalysis: From Environmental Remediation to Energy Conversion

“…Advanced Oxidation Processes (or Advanced Oxidative Technologies) stand out among the new technologies potentially useful for the minimization of environmental impacts to biota (Ismail et al, 2009), and, among these technologies, are the photocatalytic degradation of contaminants in the environment, especially using solar radiation Ziolli & Jardim, 1998;Machado et al, 2003a;Duarte et al,2005;Augugliaro et al, 2007;Machado et al, 2008). They are characterized by being able to degrade a wide range of organic contaminants into carbon dioxide, water and inorganic anions through reactions involving oxidizing species, particularly hydroxyl radicals which have a high oxidizing power (E o =2.8 V) (Nogueira & Jardim, 1998;Machado et al, 2003a;Machado et al, 2008;Kumar & Devi, 2011).…”

“…The great potential of heterogeneous photocatalysis has been demonstrated mainly in the treatment of industrial effluents and wastewater through the degradation of contaminants (Malato et al, 1997;Andreozzi et al, 1999;Malato et al, 2002;Sattler et al, 2004aSattler et al, , 2004bDuarte et al, 2005;Pons et al, 2007;Palmisano et al, 2007a;Machado et al, 2008). A significant number of these studies have focused on the photocatalytic properties of TiO 2 , suggesting a promising use of this material in heterogeneous photocatalysis (Mills & Hunte, 1997;Malato et al, 2002;Mills et al, 2002;Machado et al, 2003a;Machado et al, 2003b;Sattler et al, 2004aSattler et al, , 2004bDuarte et al, 2005;Palmisano et al, 2007a;Pons et al,2007;Machado et al, 2008;Oliveira et al, 2012) .…”

“…A significant number of these studies have focused on the photocatalytic properties of TiO 2 , suggesting a promising use of this material in heterogeneous photocatalysis (Mills & Hunte, 1997;Malato et al, 2002;Mills et al, 2002;Machado et al, 2003a;Machado et al, 2003b;Sattler et al, 2004aSattler et al, , 2004bDuarte et al, 2005;Palmisano et al, 2007a;Pons et al,2007;Machado et al, 2008;Oliveira et al, 2012) .…”

“…The possibility of utilization of solar radiation, because they have the range of absorption expanded to the visible, makes it possible achieve important contributions in solving problems concerning effluent treatment (Machado et al,2008). Machado and coworkers (2003b;2011;Duarte et al, 2005) have studied composites prepared by the association between zinc phthalocyanine (ZnPc) and titanium dioxide, obtained by coating TiO 2 particles using a solution of zinc phthalocyanine followed by controlled drying of the organic suspension (Machado et al, 2008). These materials have been intensively characterized (Machado et al, 2008;Batista et al, 2011).…”

Construção de câmara de luz ultravioleta para fotopolimerização de fases estacionárias monolíticas

“…Estes aparelhos incluem desde reatores fotoquímicos, capelas germicidas até fornos de microondas, que vêm sendo utilizados nos laboratórios. [1][2][3] Tal eficiência está relacionada ao fato de que determinados sistemas químicos podem absorver energia eletromagnética de forma mais efetiva do que, por exemplo, energia térmica. Entretanto, os equipamentos de emissão de ondas eletromagnéticas para laboratório são geralmente caros e nem sempre oferecem características desejadas, como dimensões e potência compatíveis.…”