SIMULTANEOUS REMOVAL OF CADMIUM AND LEAD FROM LAUNDRY WASTEWATER USING ZINC OXIDE NANOPARTICLES FUNCTIONALIZED WITH PLANTAIN PEEL BIOCHAR

ABSTRACT Wastewater from various sources contains various pollutants, these pollutants include heavy metals such as Cadmium and Lead. This study addresses the critical issue of heavy metal pollution in laundry wastewater, specifically targeting the simultaneous removal of cadmium (Cd²⁺) and lead (Pb²⁺). The wastewater was characterised by extremely high concentrations of Cd (30.978 mg/L) and Pb (4.779 mg/L), confirming the need for effective treatment. To this end, a novel adsorbent was developed by functionalizing zinc oxide nanoparticles with plantain peel biochar (ZnO@PPBiochar). The synthesized composite was thoroughly characterized using SEM-EDX, XRD, and FTIR. Batch adsorption experiments investigated the effects of pH, contact time, and adsorbent dosage. Optimal removal efficiencies of 96.56% for Cd and 95.44% for Pb were achieved at 150 minutes, pH 10, and a 0.15 g dosage. Kinetic analysis revealed that the adsorption process followed a pseudo-first-order model, while equilibrium data were best described by the Freundlich isotherm, indicating multilayer adsorption on a heterogeneous surface. Post-adsorption characterization confirmed the successful deposition of metals onto the adsorbent surface. The findings demonstrate that ZnO@PPBiochar is an efficient, stable, and sustainable material for remediating heavy metals from complex wastewater streams, offering a promising low-cost solution for environmental cleanup