Utilização de pleurotus sajor-caju na redução da concentração de compostos fenólicos presentes no efluente da indústria de papel e celulose

Abstract

Wastewaters originated at paper and cellulose industries (PCI) are characterized by the presence of the high content of phenolics compounds, which assign prejudicial for the microorganisms involved in the conventional treatments, imposing physical and/or chemical removal before the discharge to the aerobic (secondary) pond. This work deals with the degradation capacity of phenol and total phenols present in the PCI wastewater, in submerged cultivation, by the strain of Pleurotus sajor-caju PS-2001, commercially utilized for the output of mushrooms. In addition, changes in the COD concentration in PCI wastewaters of aerobic bacterial systems treated with fungus were evaluated. Analyses of activity of laccases, LiP, VAO and MnP, total phenols, pH, colour and DQO were carried out. The fungi and bacteria growth studies were carried out using shaking flask and bioreactor. The formulation of the medium for fungus growth had 92% of PCI wastewater, supplemented with salts, glucose and soy protein. In all trials was observed a reduction in the concentration of total phenols in the medium, that may be caused by the enzymatic activity of the fungus, which involves degradation and haste, adsorption in the fungus mass and non-biological activity due to the fact that activities of laccases, LiP, VAO and MnP were detected; the adsorption of total phenols by the micelles was observed as well as a decrease in the total phenols in the absence of microorganisms. The COD and total phenols trial analyses of wastewaters with aerobic bacteria showed a faster decrease when treated with fungus, compared to the trials without fungus. Furthermore, the removal of total phenols in the bacterial trial was availed by the fungus action due to fact that the removal of the phenol compounds was higher in the wastewater treated with the fungus. Based in the obtained results, it was concluded that the white-rot fungus P. sajor-caju PS 2001 activity can be used as a part of the PCI wastewater treatment associated to the bacterial treatment.