Industrial solar collector vs alternative solar collector: Environmental impact comparison by LCA perspective / Colector solar industrial versus colector solar alternativo: Comparação do impacto ambiental por perspectiva LCA

Adequacy to sustainable development standards requires the use of methods and tools that enable the quantification and monitoring of environmental impacts related to production processes. As a subsidy to the potential reduction of impacts by solar collectors, this paper proposes an environmental evaluation, considering an alternative solar collector scenario to be compared with a commercial one, from the life cycle perspective. Using the Life Cycle Assessment (LCA) tool, the scenarios were evaluated using the SimaPro 8.5 software. The functional unit definition was defined with real system verification through the system preparation and operation in the laboratory, which is characterized as heating 26 L of water utilizing a thermosyphon system at a temperature greater than or equal to 38 ºC. Analyzing the LCA results, it was observed that the alternative system use offers environmental impacts reduction in all impact categories selected when compared to the commercial system. In addition, a sensitivity analysis was proposed considering a variation in polyester resin mass used in the alternative system. The simulation of changes in the resin resulted in even more decreases in the environmental impacts. Regarding thermal efficiency, the industrial system excelled in terms of absorption capacity and thermal reserve. Thus, the present paper using the analyzes proposed within the defined scope, allowed the comparison between the systems in such a way that it was possible to know whether the use of the alternative solar collector results in environmental advantages without losing thermal efficiency.

Porous ceramic supported TiO2 nanoparticles : enhanced photocatalytic activity for Rhodamine B degradation

Photocatalytic processes are an efficient and important technique to mineralize organic contaminants in aqueous effluents. However, it is paramount that there is a way to recover the catalyst after degradation. Based on this problem, this research seeks to evaluate the photocatalytic properties of TiO2 under porous ceramics support for the degradation of Rhodamine B (RhB). TiO2 was synthesized by sol-gel, dried at 100 ◦C and calcined at 400 ◦C. The morphological, optical and structural proprieties of the particles were characterized. The XRD patterns of samples calcined at 400 ◦C showed only the anatase phase, confirmed by Raman. Not heat-treated xerogel was amorphous. The agglomerates are composed of fine particles, in the nanometric scale of 15nm. The bandgap of the powder is 3.21 eV, and the surface area is 60.1m2 g−1. To evaluate its photocatalytic activity, the anatase TiO2 was supported in a porous ceramic substrate by a dip-coating process. The heterogeneous photocatalysis showed excellent results, with the degradation of up to 83% of RhB. It was possible obtained with successful an efficient technique for the treatment of wastewater with Anatase nanoparticles supported in the ceramic support obtained from of reuse of the residues.Los procesos fotocatalíticos son técnicas eficientes para la mineralización de contaminantes orgánicos en efluentes acuosos. Sin embargo, es fundamental que haya una forma de recuperar el catalizador después de la degradación. En base a este problema, esta investigación busca evaluar las propiedades fotocatalíticas del dióxido de titanio (TiO2) bajo el soporte de cerámica porosa para la degradación de la rodamina B (RhB). El TiO2 se sintetizó mediante sol-gel, se secó a 100 ◦C y se calcinó a 400 ◦C. Se caracterizaron las propiedades morfológicas, ópticas y estructurales de las partículas. Los patrones DRX de las muestras calcinadas a 400 ◦C mostraron solo la fase anatasa, confirmada por Raman. El xerogel no tratado térmicamente era amorfo. Los aglomerados están compuestos de partículas finas, en la escala de 15nm. El intervalo de banda es de 3,21 eV, y el área de superficie es de 60,1m2.g−1. Para evaluar la actividad fotocatalítica, se recubrió un sustrato cerámico poroso mediante el proceso de recubrimiento por inmersión. La fotocatálisis heterogénea mostró excelentes resultados, con la degradación de hasta el 83% de la RhB. Fue posible obtener con éxito una técnica eficiente para el tratamiento de aguas residuales con nanopartículas de anatasa soportadas en el soporte cerámico obtenido de la reutilización de los residuos