Sustainable Bio-Nanotechnology for Water Purification: Synergistic Adsorption and Antimicrobial Effects of Pomegranate Peel and Green Tea Extract

Purpose: Water contamination by heavy metals and pathogenic microorganisms poses severe risks to human health and ecosystems, particularly in developing countries. The purpose of this study was to design and evaluate a sustainable bio-nanocomposite for dual-function water purification by integrating agro-waste and medicinal plant extracts. Methods: A chitosan-based nanocomposite incorporating pomegranate peel extract (PPE) and green tea extract (GTE) was simulated for adsorption of Pb²⁺, Cd²⁺, and As³⁺ ions, and antimicrobial activity against Escherichia coli and Staphylococcus aureus. Adsorption was modeled using Langmuir and Freundlich isotherms, and kinetics were fitted to pseudo-first- and pseudo-second-order models. Antimicrobial performance was evaluated through inhibition zone analysis and time–kill modeling. Results: The nanocomposite achieved maximum simulated adsorption capacities of ۴۴.۲ mg/g for Pb²⁺, ۴۱.۳ mg/g for Cd²⁺, and ۳۸.۲ mg/g for As³⁺. Antimicrobial simulations indicated >۹۰% bacterial reduction within ۳ hours, with inhibition zones of ۱۸ mm for E. coli and ۱۵ mm for S. aureus. Comparative analysis showed superior performance of PPE–GTE compared with conventional adsorbents. Reusability tests demonstrated retention of >۷۰% efficiency after five regeneration cycles. Conclusion: The PPE–GTE nanocomposite offers a green, low-cost, and effective strategy for simultaneous heavy metal removal and microbial disinfection. This approach highlights the potential of bio-nanotechnology in providing sustainable water purification solutions, particularly in resource-limited regions.

کلیدواژه ها:

Bio-nanotechnology ، Water purification ، Pomegranate peel ، Green tea extract ، Adsorption ، Antimicrobial