Review: Synthesis of Biomass-Based Silica Gel-Supported Metallic Nanoparticles for Disinfection of Drinking Water

This review work highlights the eco-friendly synthesis and application of biomass-derived silica gel (SG)-supported metallic nanoparticles (MNPs), primarily focusing on their potential for sustainable drinking water disinfection and utilizing abundant biomass waste, such as agricultural residues, to extract silica through processes like pyrolysis, chemical treatment, or hydrothermal methods, creating a versatile support with high surface area, porosity, and biocompatibility. MNPs, notably silver, copper, zinc, etc., are immobilized onto these silica frameworks via green synthesis techniques, including plant extract-mediated methods, chemical reduction, and sol–gel processes, resulting in nanocomposites with controlled size, distribution, and enhanced stability. These MNPs are known for their potent antimicrobial activity, capable of inactivating a broad spectrum of pathogens like Staphylococcus aureus and Escherichia coli. Silica gel supports mitigating issues such as nanoparticle aggregation and leaching, thus improving reusability and environmental safety. The synthesis parameters of nanoparticle size, concentration, surface chemistry, and contact time directly influence disinfection efficacy, while biomass-based supports offer advantages including cost-effectiveness, environmentally benign production, and minimal pollution. Incorporating biomass-derived silica gel-supported AgNPs into water treatment systems presents a promising, sustainable alternative to conventional chemical methods like chlorination and ultraviolet (UV) irradiation, which can generate hazardous byproducts. These nanocomposites demonstrate significant potential in resource-limited settings due to their high surface area, porosity, and reusability, although concerns such as nanoparticle leaching, toxicity, scalability, and environmental impact warrant further investigation. Overall, biomass-supported MNPs represent an innovative frontier in water purification technology, aligning with principles of green chemistry and sustainability. Emphasizing the importance of optimizing synthesis protocols and assessing long-term safety, this review underscores their capacity to advance eco-friendly water disinfection strategies that can improve public health and promote sustainable water management practices worldwide.