Combined electric field treatment with copper and silver for water disinfection
摘要
Domestic water is of great importance to our modern lives and yet opportunistic pathogens like Legionella, Cryptosporidium, and Giardia are the largest cause of outbreaks and illnesses in our potable water supply. Previously, electric field treatment (EFT) in combination with copper (Cu) was studied at the microscale and found to have synergistic performance enhancing the inactivation of bacteria. In this study, a lab-on-a-chip device is used to better understand, observe, and quantify the synergistic effect when combining EFT with Cu and Ag for water disinfection. Staphylococcus epidermidis is studied as a model bacterium. Using Cu and/or Ag ions with various concentrations as the chemical disinfection agents and EFT as the physical disinfection aid, we can ultimately reduce the metal ion concentration and energy required to achieve effective inactivation of bacteria. In this study, the highest synergies were measured using EFT with Cu and Ag together, for example, achieving > 95 % inactivation using only 34 kV/cm electric field strength, 200 µg/L Cu, and 10 µg/L Ag. These results can be used to optimize and customize the disinfection performance of EFT devices to adapt for its various point-of-use applications.