Disinfection of viable Pseudomonas stutzeri in ultrapure water with ion exchange resins

This study describes the disinfection of gram-negative bacteria, Pseudomonas stutzeri, isolated from ultrapure water (total organic carbon 5 ppb; effluent resistivity, > 18 M Omega cm at 25 degrees C) with ion exchange resins using a batchwise procedure. A single bed of strong base anion exchange resin (SBAER) in OH- form shows disinfection ability; however, a bed of strong acid cation exchange resin (SACER) in H+ form does not. Adsorption of bacteria on SBAERs occurs mainly due to the electrostatic attraction between positively charged SBAERs and negatively charged bacteria. In addition, hydrophilic interactions between SBAERs and bacteria are considered based on the results of adsorption isotherms. Since the positively charged SBAERs in Cl- form have no bactericidal effect, OH- ions are utilized for disinfection. Acrylic SBAERs in OH- form were more effective at disinfection than styrenic SBAERs. A mixed bed of SBAERs in OH- form and SACERs in H+ form also disinfects bacteria more effectively.