Produção de Quitosana por Absidia corymbifera em meio de baixo custo e aplicação na descoloração de efluente industrial

Abstract

This work was evaluated the ability of commercial chitosan as sorbent powder and biotechnologically processed microspheres in the decoloration of industrial wastewater, being used at a concentration of 0.514 g per 50 ml of effluent. The results showed a significant reduction of COD (Chemical Oxygen Demand) by chitosan microspheres (99%) than powder (96%), during 168 hours of contact. Similar results were obtained during the decolorization of the industrial effluent; it was revealed a color removal of wastewater to 98% and 96%, respectively, for microspheres and chitosan powder in the same period of contact. The results obtained with chitosan powder were used for the studies with the microbial production of chitosan by Absidia corymbifera, considering the low cost of that process. The experiments were carried out using a 23 full factorial design, with variables such as industrial waste corn steep liquor (obtained from milling of corn), glycerin (obtained from excess of production of biodiesel) and urea, with the variables response and biomass production of chitosan. The results indicated the maximum yield of biomass of 21g/L and 88mg/g of chitosan. The microbiological polymer was characterized by absorption spectra of the infrared ray and X-ray diffraction, indicating 90.3% of deacetylation and a crystallinity index of 21%. The efficiency of chitosan powder in adsorption was evaluated using a 2² factorial design, with variables like the concentration of chitosan and agitation in the response variable discoloration. The results showed a removal process of 100.0% of the color of the effluent from industry of soft drinks and juices, and a COD reduction of 99.8% and 90.0% of TSS (total suspended solids). Thus, the results confirmed the effectiveness of microbiological chitosan powder in the biotechnological process of decolorization of effluent, suggesting that an alternative method to minimize pollution of receiving waters and water reuse