Continuous Lab-Scale Fungal Bioreactors for Post-Treatment of Weak Black Liquor Effluents from Kraft Pulp Mills

摘要

The purpose of this work was to evaluate and compare two continuous, lab scale bioreactors for the post-treatment of anaerobically-pretreated weak black liquor (herein after named anaerobic effluent, AnE, which still contains significant concentrations of recalcitrant organic matter). One unit was a packed bed bioreactor (PBBR) loaded with Trametes versicolor (TV) immobilized in small cubes of holm oak wood (biocubes); the second one was a fluidized bed bioreactor (FBBR) also loaded with biocubes of holm oak wood colonized by Lentinus edodes {Le). The influent was AnE with pH adjusted to 4.5 and continuously fed to both bioreactors, which were operated for 60 days at 5 day hydraulic retention time. Sterile air was continuosly sparged into reactors for providing oxygen. Response variables monitored were unit, net removal efficiency and unit, net, specific removal efficiency (r|un y rsun respectively) of COD, color, and ligninoids, and enzymatic activities of manganeseperoxidase (MnP), ligninoperoxidase (LiP), laccase (Lac) and proteases.