Low-dose ozonation enables rapid biodegradation of bio-based filtration membranes

The widespread use of polymer membranes poses emerging environmental concerns, necessitating sustainable alternatives beyond land disposal. While biodegradation offers a green solution, its time-consuming nature prompts exploration of more efficient techniques. Present study investigated the use of low-dose ozonation as a pre-treatment before biodegradation for the demineralization of polymer membranes. Initially, ozonated membranes were characterized using various analytical techniques such as scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD), surface zeta potential and mechanical strength analysis to examine changes in their physio-chemical properties. These changes suggest a disruption in the structure of complex polymer compounds and reduced mechanical strength, making them more biocompatible. Post ozonation, biodegradation was carried out using the commonly used microorganisms such as fungi Trametes versicolor and bacteria Escherichia coli MG1655 in anaerobic conditions. Complete degradation in cellulose acetate (CA) and polycaprolactone (PCL) based mixed matrix membranes was achieved after ozone consumption of 19.73 ± 8.98% g ozone/g membrane, followed by fungi-assisted biodegradation within 30 days. The combined process resulted in 39.4 ± 2.8% degradation with E. coli MG1655 -assisted biodegradation. This study highlights the effectiveness of low-dose ozonation followed by biodegradation as an eco-friendly, scalable with minimal environmental impacts approach for polymer membranes demineralization.