Estudo da biodegradação de efluente kraft por fungos ligninolíticos

Abstract

Even with all the technological advances available, the pulp and paper industry is one of the biggest water consumer, presenting an effluent rich in lignin compounds, organic matter, color and toxicity. The present work aimed to study the capacity and efficiency of ligninolytic fungi to degrade compounds present in kraft wastewater. Experiments were conducted first on solid medium and after in liquid medium, in a sequence of four steps. The first study carried out the physico-chemical characterization of the effluent. In the second, different concentrations of the effluent (from 0 % to 100 %) mixed with agar (1,5%) were distribuited on Petri in order to evaluate its effect on mycelial growth of Phanerochaete chrysosporium ATCC 24725, Agaricus bisporus ABI 25 and Pleurotus florida PSP 1. Considering the results , the third experiment was conducted in liquid medium, in a factorial experiment 23, varying glucose, pH and concentration of effluent. In this experiment biomass, ligninic compounds , color and toxicity to Daphnia magna and Lactuca sativa were evaluated. In the final step a ten day kinetic was conducted, monitoring parameters every two days. Mycelial growth on solid medium showed best results for Pleurotus florida and Phanerochaete chrysosporium. In ligd medium best results were obtained for P. florida cultivated on 10% of effluent Kraft , pH 7 and by adding 10 g / L glucose. Result of removing color removal was about 65% and ligninic compounds around 95%. Regarding the kinetic assay correlation was observed between lignin and color removal and the formation of biomass. Production of manganese peroxidase was 593.98 U/mL. Pleurotus florida showed potential for biodegradation of compounds present in wastewater Kraft, but further studies should be conducted.