Fabrication and Evaluation of Filtration Membranes from Industrial Polymer Waste

Polyvinylidene fluoride (PVDF) polymers are known for their diverse range of industrial applications and are considered important raw materials for membrane manufacturing. In view of circularity and resource efficiency, the present work mainly deals with the reusability of waste polymer 'gels' produced during the manufacturing of PVDF membranes. Herein, solidified PVDF gels were first prepared from polymer solutions as model waste gels, which were then subsequently used to prepare membranes via the phase inversion process. The structural analysis of fabricated membranes confirmed the retention of molecular integrity even after reprocessing, whereas the morphological analysis showed a symmetric bi-continuous porous structure. The filtration performance of membranes fabricated from waste gels was studied in a crossflow assembly. The results demonstrate the feasibility of gel-derived membranes as potential microfiltration membranes exhibiting a pure water flux of 478 LMH with a mean pore size of similar to 0.2 mu m. To further evaluate industrial applicability, the performance of the membranes was tested in the clarification of industrial wastewater, and the membranes showed good recyclability with about 52% flux recovery. The performance of gel-derived membranes thus demonstrates the recycling of waste polymer gels for improving the sustainability of membrane fabrication processes.

Automated summary

This study focuses on the reusability of waste polymer 'gels' produced during the manufacturing of PVDF membranes. Solidified PVDF gels were used to prepare membranes via the phase inversion process, and the fabricated membranes retained molecular integrity and exhibited a symmetric bi-continuous porous structure. The membranes fabricated from waste gels showed potential as microfiltration membranes with a pure water flux of 478 LMH and a mean pore size of about 0.2 μm. Additionally, the membranes demonstrated good recyclability in the clarification of industrial wastewater with a flux recovery of about 52%.