In the present world, raw materials are in greater demand but are becoming ever scarcer. To imply the sign of criticality, knowing that there is a high risk of supply shortage and economic impact, the European Commission formally adopted a list of specific raw materials designated as 'critical raw materials' (CRMs) as represented in Fig. 1. Regulatory policies are being implemented to bring down the extraction/mining trend for ultimately extending the lifetime of CRMs. On the other hand, advanced recycling systems are being practiced to promote and establish a core circular economy context by recycling, recovering, and separating CRMs. These recycling approaches are mostly aimed at the recovery of various metals such as palladium, gallium, germanium, copper, which are critical raw materials for the technology sector. There are also a specific group of CRMs including Phosphorus (P), natural phosphate rock and Magnesium (Mg) representing major primary, and secondary resources for industrial applications of high economic value (Loganathan et al., 2017; Yan et al., 2018). Crucially only P and Mg are deemed suitable candidate CRM's for recovery from waste streams through effective separation and recycling strategies. Further, its supply-demand status and substitutability risks have driven the requisites for resource supplementing technology through effective recovery and recycling strategies.

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 ~0.2 µm. 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.