Vinasse degradation using Pleurotus sajor-caju in a combined biological – Electrochemical oxidation treatment

Abstract Industrial wastewater treatment, by combined processes, has recently been seen as a novel and economically attractive strategy. The use of Pleurotus sajor-caju , followed by electrochemical oxidation (EO) for sugarcane vinasse degradation was investigated. Vinasse degradation treatment with P. sajor-caju yielded efficient color removal (97%), turbidity (99%), chemical oxygen demand (COD) (50.6%), and total organic carbon (TOC) (57.3%). Ligninolytic enzyme production was seen, and the highest laccase activity were obtained after 12th day of fermentation (varying between 341–400 UI L –1 ) and for peroxidase manganese the highest activity was seen between the 9th and 12th day of fermentation (varying between 1400–1494 UI L –1 ). Concomitantly, the mycelial biomass presented a high concentration (13.63 g L –1 ) on the 15th day of growth. In optimized conditions, the EO using as anode Ti/(RuO 2 ) 0.7 (IrO 2 ) 0.1 (Sb 2 O 3 ) 0.2 further degraded vinasse, reaching a final color removal of 100%, COD of 66% and TOC of 61%. This additional procedure allowed the elimination of vinasse toxicity reaching 0% lethality for Lactuca sativa and Raphidocelis subcapitata.