DESENVOLVIMENTO DE ADSORVENTES OBTIDOS A PARTIR DE VAGEM DA MORINGA OLEÍFERA IMPREGNADAS COM LICOR PRETO

Abstract

The Brazilian textile industry has one of the largest and most complete textile chains in the West, being one of the main producers and consumers of jeans in the world. Textile production requires a high consumption of water, especially in the dyeing stage, which results in a large amount of waste, which is highly toxic and bulky and is often improperly disposed of. These residues contain synthetic dyes that do not completely fix to the fibers during the dyeing process, resulting in effluent contamination. The consequence is damage to water resources, since most dyes can be toxic and bioaccumulators, presenting risks to human health and the ecosystem. A practical and low-cost approach to effluent treatment is the use of adsorption techniques, especially with coal-type adsorbents. This material has high porosity and high adsorption capacity. In addition, charcoal obtained from plant origin, biochar, and industrial waste contributes to environmental preservation. In this context, the objective of this work was to produce adsorbents from Moringa oleifera pods impregnated with black liquor, for the treatment of wastewater containing methylene blue and indigo carmine, dyes used in the textile industry. The precursor material was characterized using the Fourier Transform Infrared technique, which showed the functional groups present in the pod before and after pyrolysis. Thermogravimetric analysis of the pod showed elimination of moisture and volatiles up to 140°C, followed by degradation of cellulose and hemicellulose. The low values of moisture content, 8.20%, and ash, 3.12%, indicate that the material is promising for biomass. All pyrolyzed material was evaluated in the adsorption of methylene blue and indigo carmine. The charcoal obtained from the pod impregnated with potassium hydroxide showed a maximum removal of 42.61%, and the sample of the pod impregnated with liquor, in the proportion 1:1, showed a removal of 38.50% for methylene blue and 15.85%, in the removal of indigo carmine. Therefore, studies have shown that the carbonaceous material obtained from the moringa pod performs better with cationic dyes and when impregnated with potassium hydroxide.