Polycaprolactone-zinc oxide biocomposite membranes for wastewater treatment by ultrafiltration process: Synthesis, characterization and removal of inorganic pollutants

• Published in: Journal of environmental chemical engineering 2024-12, Vol.12 (6), p.114698, Article 114698
• Main Authors: Benhacine, Fayçal, Lounis, Feriel Meriem, Hadj-Hamou, Assia Siham, Toumi, Daoud Aboubekeur, Ferroukhi, Abdelmalek Chouaib
• Format: Article
• Language: English
• Subjects: Biocomposite; Poly (ε-caprolactone); Ultrafiltration membrane; Urban waste water treatment; Zinc oxide
• ISSN: 2213-3437
• DOI: 10.1016/j.jece.2024.114698

The severe droughts impacting North Africa have intensified the pressure on potable water supplies and agricultural irrigation, highlighting the urgent need for sustainable water management solutions. This study explores the potential of poly(ε-caprolactone)/zinc oxide (PCL/ZnO) biocomposites as ultrafiltration membranes for treating urban wastewater, with the goal of enabling water reuse in agriculture. PCL/ZnO membranes, fabricated using the solvent-casting method, were thoroughly characterized using FTIR, XRD, EDAX, SEM, AFM, DSC, TGA, and water contact angle (WCA) measurements. Key findings revealed that increasing ZnO content (1–4 wt%) significantly enhanced membrane thickness, crystallinity, mechanical robustness, and surface roughness, while lowering WCA values to improve hydrophilicity. These enhanced properties are critical for ultrafiltration, as they contribute to higher contaminant rejection and improved water permeability. Performance tests demonstrated ion retention rates of 32–61 % post-filtration, including for toxic metals, effectively reducing pollutant levels. Notably, the treated water met the Food and Agriculture Organization (FAO) standards for irrigation quality, indicating its suitability for agricultural applications. This work highlights the efficacy of PCL/ZnO membranes in facilitating sustainable wastewater recycling under drought conditions, presenting a promising, adaptable solution for water reclamation in water-scarce regions. The results underscore the potential of these biocomposite membranes to advance sustainable water treatment practices, supporting both environmental resilience and agricultural productivity. [Display omitted] •Biocomposite membranes of Poly (ε-caprolactone) (PCL) with zinc oxide nanoparticles (ZnO NPs) were developed by solvent casting.•ZnO NPs enhanced hydrophilicity, surface roughness, and mechanical properties, improving membrane performance.•High rejection rates of heavy metals (Pb²⁺, Cd²⁺) were achieved.•Treated wastewater quality met FAO standards for potential irrigation reuse.