Heavy metal pollution is a major environmental issue, with industrial and agricultural activities increasing metal concentrations in water. Effective treatment methods are crucial, and adsorption is one of the most efficient techniques. This study combines microbial proteins (MPs) from waste cheese whey permeate with biodegradable cellulose acetate to create nanocomposite mats via electrospinning. The resulting mats exhibit high adsorption capacity for lead (66.23 mg/g) and stability, demonstrating their potential as sustainable bio-adsorbents for wastewater treatment. The material's reproducibility, high efficiency, and eco-friendly nature make it a promising solution for heavy metal removal.