Quebracho tannin treatment with Aspergillus tubingensis MUT 990 immobilized in polyurethane foam cubes in a novel submerged cage reactor

Quebracho tannin represents one of the most used tannin in industrial vegetable tanning process and one of the most recalcitrant compounds in tannery wastewaters. In this study treatment of a quebracho tannin solution in a 4 liters reactor (not sterile conditions) was carried out with a selected fungal strain, Aspergillus tubingensis MUT 990. The fungal strain was grown in polyurethane foam cubes carriers (2 cm size) submerged in a rotating cage inside an aerated reactor. The Hydraulic Residential Time (HRT) was 24 hours and the pH setpoint was 5.5. The experiment lasted two months (still ongoing) and the biofilm was maintained with about 20% removal of soluble COD. Furthermore, on-line and off-line respirometry were used to characterize fungal biomass activity.