Abstract
This study investigated remediation of copper (Cu²⁺) contamination in wastewater through the creation of a sustainable adsorbent derived from coal fly ash (CFA), an industrial byproduct, and assesses its dual functionality in heavy metal removal and antimicrobial applications. A zeolite produced by hydrothermal treatment of CFA exhibited exceptional Cu²⁺ adsorption effectiveness (99.99% at pH 6, with a starting concentration of 50 mg/L) due to its mesoporous structure (surface area: 174.4 m²/g). It has also had a negatively charged surface over a wider pH range which favoured cation uptake. Adsorption conformed to the Freundlich isotherm, indicating multilayer interactions, and exhibited pseudo-second-order kinetics, implying chemisorption. A thermodynamic study validated a spontaneous, exothermic reaction. The functionalisation of the Cu²+-loaded zeolite with silver nanoparticles (AgNPs), produced using a Moringa Oleifera extract, improved its antibacterial effectiveness against E. coli, resulting in an 18 mm inhibitory zone. The characterisation techniques ((SEM (Scanning electron microscopy), TEM (Transmission electron microscopy), XRD (X-ray diffraction), FTIR (Fourier-transform infrared spectroscopy), BET (Brunauer-emmett-teller)) confirmed the structural development, Cu²⁺ inclusion, and AgNPs coating. The zeolite nanoabsorbent's dual functionality—effective Cu²⁺ removal and antibacterial properties—underscores a circular economy strategy, recycling exhausted adsorbents to reduce secondary pollution. This study highlights the potential of waste-derived materials in sustainable water treatment and biomedical applications, connecting environmental engineering with green nanotechnology.