Antimicrobial activity of immobilized CuNPs, Cu₂ONPs and CuONPs for continuous water purification

Chlorination is the most widely used method for water disinfection, but it is believed to be toxic for human consumption. Therefore, there is a great need to develop an environmentally friendly purification method that can prevent bacterial contamination in water supply systems. It is possible to replace conventional water treatment methods with more promising, modern technologies which combine polymers with antibacterial agents such as copper and its oxides as nanoparticles (NPs). Such NPs are known to exhibit high antibacterial, antifungal and antiviral properties. In our research we developed a continuous water disinfection process using polymeric composites composed of immobilized NPs of copper, cuprous oxide and copper oxide. The obtained composites exhibited high antibacterial activity and showed low release of copper ions into the aqueous phase, reducing health risks due to possible copper-ion consumption. The CuNP and Cu₂ONP composites were active against S. aureus for seven days, and against E. coli for 22 days, in a continuous flow regime. The composites with the highest antibacterial activity are potential materials for tap-water disinfection.