Immobilization of UiO-66/Brown-rot fungi (BRF) in PVA-SA matrix and its performance for methylene blue decolorization

Dye pollution is an environmental problem faced by many countries. Dyes such as methylene blue (MB) are harmful and toxic to the environment and human health when they contaminate water. In this study, new composites were fabricated from brown rot fungus (BRF) and MOF UiO-66 immobilized in polyvinyl alcohol and sodium alginate (PVA-SA) matrix to degrade MB dye. BRF species used: Gloeophyllum trabeum (GT) and Daedalea dickinsii (DD), each species mixed with variations of UiO-66 60, 120, and 180 mg. The results showed that the MB decolorization percentages of UiO-66(180)/GT@PVA-SA and UiO-66(60)/DD@PVA-SA were better than the pure cultures (88.29 ± 0.38% and 72.05 ± 0.57%). While the maximum adsorption capacities (q_m) of UiO-66/GT@PVA-SA and UiO-66/DD@PVA-SA were 0.5510 mg g⁻¹ and 0.3290 mg g⁻¹, respectively, these values were still very low compared to UiO-66. The metabolic products of MB degradation by UiO-66/DD@PVA-SA were identified as C₁₆H₂₀N₃S (m/z 286), C₂₂H₃₂N₃O₅S (m/z 450), and C₁₂H₁₃N₃O₇ (m/z 311). Conversely, the degradation of MB by UiO-66/GT@PVA-SA granules produced two metabolites, C₁₆H₁₉N₃O₂S (m/z 318) and C₂₂H₃₂N₃O₅S (m/z 450). These results confirm that UiO-66/BRF immobilized on the PVA-SA matrix has the potential to decolorize MB.