Immobilized nanoparticles of copper and copper oxides for water disinfection

Disinfection of drinking water has become an important global problem. Conventional methods of disinfection, such as filtration, ozonation and UV treatment, do not prevent microbial contaminations in water pipes, and chlorination is harmful due to release of toxic byproducts. In our research we propose an additional stage of water disinfection based on the incorporation of copper nanoparticles (CuNPs) and copper oxide nanoparticles (CuONPs and Cu₂ONPs) on polymeric tubes or in cartridges, which may be combined with conventional water treatments. Copper and copper oxide nanoparticles were immobilized onto polyethylene by thermal adhesion. Antimicrobial activity was tested against Gram-positive S. aureus and Gram-negative E. coli. The highest antibacterial activity was demonstrated by immobilized CuNPs and Cu₂ONPs within half an hour. The samples retained their bactericidal activity for at least 13 cycles of re-use. Immobilized CuONPs caused total eradication of S. aureus cells during two first cycles, whereas no activity was observed against E. coli cells. CuNPs and Cu₂ONPs immobilized onto a polymeric surface have the potential for being used in tap water disinfection.