Investigating the Recovery of PVDF/TiO2 Photocatalyst for Methylene Blue Degradation

The increasing environmental concerns over and demand for sustainable solutions have driven research into the efficient recovery and reuse of waste materials, particularly from photocatalysts used in wastewater treatment. This study addresses the critical challenge posed by used PVDF/TiO2 photocatalysts, which, if not properly managed, contribute to environmental pollution. A practical recovery technique based on the phase inversion method was developed to separate and purify PVDF, TiO2, and the solvent NMP from used composite materials. This method led to recovery rates of 95.17% for PVDF, 98.35% for NMP, and 67% for TiO2. The recycled photocatalyst was then reassembled and tested for its ability to degrade methylene blue, a common dye pollutant. A Box–Behnken design was employed to optimize the treatment conditions, ensuring the process was both efficient and reproducible. The regenerated material achieved up to 99.6% efficiency in the first cycle, with a slight reduction in efficiency observed across subsequent cycles, maintaining over 92% efficiency after 10 cycles. These findings confirm that effective recovery of photocatalytic materials is not only feasible but also beneficial in reducing waste and maintaining high treatment performance.