Anaerobic treatment of real cosmetic wastewater in a lab-scale UASB using fungal biocatalysts: COD/TOC removal and methane yield (Pleurotus ostreatus vs Trametes versicolor)

Abstract

Real cosmetic wastewater is chemically complex and often difficult to treat using conventional processes. This study investigated continuous anaerobic treatment in a 3.0-L upflow anaerobic sludge blanket (UASB) reactor operated with polyurethane-immobilized white-rot fungi, Pleurotus ostreatus and Trametes versicolor. Real plant effluent was fed under hydraulic retention times (HRT) of 15, 30, and 45 h to evaluate pollutant removal and biogas performance. The reactor remained stable throughout operation, with effluent pH between 6.4 and 6.7 and intact fungal pellets. COD removal increased with HRT, reaching 84.0 % for P. ostreatus and 90.4 % for T. versicolor at 45 h. TOC removal followed a similar trend, attaining 78.0 % and 76.0 %, respectively. Color removal reached 68.7 % for P. ostreatus and 79.5 % for T. versicolor. Cumulative biogas production was 300 mL for P. ostreatus and 250 mL for T. versicolor, with methane fractions of 60 % and 55 %. Specific methane yields increased with HRT, achieving 178 and 165 mL CH4 g(-1) VS at 45 h. Overall, T. versicolor exhibited superior decolorization, whereas P. ostreatus produced more methane-rich biogas. These findings demonstrate the potential of fungal UASB systems as low-energy, biologically driven treatment options for dye-rich cosmetic wastewater.