Fenton-like disinfection properties of polyethyleneimine/polyaniline-modified SiO2-loaded copper composites and exploration of lab-scale continuous-flow reactor applications

Bacterial contamination in aquatic environments remains a persistent threat to public health. In this study, we synthesized copper nanoparticle-loaded polyethyleneimine/polyaniline-functionalized SiO2 composites (Cu/PEI/SiO2 and Cu/PANI/SiO2) as novel Fenton-like catalysts for water disinfection. The composites were systematically characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM), confirming the successful integration of copper nanoparticles into the matrix. Fenton-like disinfection experiments demonstrated that both composites achieved complete inactivation (7-log reduction) of Escherichia coli (E. coli), Ralstonia solanacearum (R. solanacearum), and Staphylococcus aureus (S. aureus) within 15, 20, and 25 min, respectively. Electron paramagnetic resonance (EPR) spectroscopy confirmed the presence of hydroxyl radicals (•OH) and superoxide radicals (•O2⁻) in both composites, verifying a radical-mediated disinfection mechanism. To assess practical applicability, we constructed a lab-scale continuous-flow reactor. Long-term tests revealed that both composites maintained consistent and effective bactericidal performance over a 4-hour continuous operation, exhibiting excellent stability and durability. These findings highlight the potential of Cu/PEI/SiO2 and Cu/PANI/SiO2 as efficient, sustainable materials for advanced water disinfection technologies.