Development of low-cost styrofoam-based membranes incorporating micro-activated carbon for removal of microalgae

The accumulation of styrofoam waste poses a major environmental issue due to its non-biodegradable nature and limited recyclability. This study introduces an upcycling approach by fabricating flat-sheet filtration membranes from waste styrofoam incorporating micro-activated carbon to enhance performance. Membranes with varying carbon loadings (0–0.4 wt %) were assessed for water flux, porosity, contact angle, morphology and microalgal rejection. Increasing activated carbon content improved permeability from 10.98 to 46.16 LMH bar−1, while contact angle decreased to 63.2°, indicating enhanced hydrophilicity. Porosity increased to 90%, and SEM revealed higher pore density and surface roughness. All membranes achieved 100% rejection of Spirulina platensis with permeate turbidity of 0 NTU. The EPS-AC 0.4 membrane demonstrated the best overall performance. These results confirm that styrofoam waste can be effectively converted into sustainable, high-performance filtration membranes, offering both environmental and technological benefits.