Microbial Inactivation in Water Using Pulsed Electric Fields and Magnetic Pulse Compressor Technology

Abstract

Pulsed electric field (PEF) disinfection is a promising technology for the nonthermal disinfection of water. Magnetic pulse compressors due to their high repetition rates and lifetimes, appear to be a promising alternative to the existing pulse forming circuits used for sterilization applications. The application of these systems for the purification of water has yet to be explored. The use of the short duration electrical pulses from the magnetic pulse compressor for inactivation of spores, bacteria (Escherichia coli) and viruses in drinking water is being investigated at the University of Missouri, Columbia. The test cell designed herein allows flowing tests for pulsewidths of 130-500 ns. The coupling of the magnetic modulator with the test cell and the inactivation protocols that aim at effective inactivation under optimal conditions are discussed. A 4 log reduction was seen for (Escherichia coli) E. coli at field strengths of 110 kV/cm and 70 pps, with a total energy consumption of 40 J/cm3. A comparative study of different parameters, e.g., pulsewidth, electrode gap, frequency, and electric field, which effect the microbial inactivation are also presented