Biosorption of uranium from water on polymethylmethacrylate microplastic immobilized with Saccharomyces cerevisiae: a sustainable approach

Sequestration of uranium from water requires the development of effective materials coupled with an innovative and sustainable approach. In this regard, we propose an inventive design of an adsorbent material involving microplastic-microbe synergy. The non-pathogenic microbe Saccharomyces cerevisiae was immobilized on polymethylmethacrylate (PMMA), a widely used thermoplastic. PMMA in its pure form and acrylic microplastic waste were used separately to synthesize biosorbents for the removal of uranium. The active functional groups on the yeast cell wall embedded in the acrylic plastic ensured effective binding of the metal on the biosorbent. The detailed results from SEM-EDAX, TGA, XPS, FTIR, and BET analysis of the biosorbent elucidated our understanding of the mechanistic interactions involved in the adsorption process. The Langmuir maximum adsorption capacities obtained for the biosorbents from pure PMMA and acrylic microplastic were 200 and 197 mg g-1, respectively, at pH 5.0. The selectivity, regeneration, and application studies suggest that these biosorbents are versatile waste-to-value materials useful for environmental remediation in alignment with UN Sustainable Development Goals 2030.