Avaliação do potencial de reuso dos carvões ativados descartados após a utilização na purificação doméstica de água potável

Abstract

Activated carbons are commonly found in domestic drinking water filtration. After use, they are discarded. However, they may still have adsorptive characteristics. The objective of this study was to evaluate the adsorption potential of activated carbons from discarded domestic drinking water filters. The used carbons were obtained from a local dealer. Three different models of refills were evaluated. A new refill was purchased to provide the activated carbon that was used as a reference. The filters were opened and the activated carbon was removed for subsequent drying. The preliminary physicochemical characterization was performed by analyzing visual aspects, Fourier transform infrared spectroscopy (FTIR), nitrogen (N2) physisorption, apparent density and adsorption test, which includes iodine adsorption (iodine number in mgI2.g-1) and reactive black 5 textile dye adsorption. All results from the used carbons were compared with those from the new carbon. The results demonstrated that, even though they have already been used in water purification, the coals still preserve part of their porous characteristics and have adsorptive characteristics that allow their use in other adsorption processes, such as in the treatment of industrial effluents.