Design and Development of Pulsed Electric Field Treatment Chamber for Bacterial Inactivation

Abstract

vii newlineABSTRACT newlineBacteria free liquid food products are the customers prioritized need newlineand clean water is very crucial to every human being for drinking, cooking and newlineother everyday uses. The availability of clean water is of utmost importance, newlinewhich will lead human beings to a healthier life. Tap water may seem clear but newlinemay contain a lot of bacteria and viruses. The presence of viable pathogens in newlineliquid food and water may pose a greater threat to human health. In order to newlinedecontaminate water from the most prevalent bacterial loads viz., Escherichia newlinecoli and Faecal coliform, and to inactivate Staphylococcus aureus, a viable newlinefood borne pathogen, present research has focussed on design and newlinedevelopment of a Pulsed Electric Field (PEF) treatment chamber, where newlinetitanium electrodes were used for pulsed power applications. Initial research newlinewas made on simulating several treatment chamber designs, where a newlinemethodology was adopted to repetitively model the electrodes and the newlinechamber till an optimized design was obtained. Electrode configurations inside newlinethe chamber were modelled to analyze (i) The electric field distribution based newlineon electrode shapes (ii) The induced transmembrane potential across the cell newlineplasma membrane, when a biological cell model is placed in the interelectrode newlinegap (For parallel square, parallel circular and coaxial electrodes) (iii) The newlinepercentage reduction of electric field on electrodes edges (For near bruce newlineprofile electrodes). Microorganisms such as Staphylococcus aureus and newlineEscherichia coli were modelled and analyzed for critical field requirement. For newlineexperimental studies, the following specific microorganisms were chosen for newlineinactivation viz., Escherichia coli MTCC 433, Faecal coliform and newlineStaphylococcus aureus ATCC 25923. The study projects the significant newlineadvantages of using titanium electrodes over stainless steel, and promote the newlineuse of titanium for water decontamination. The study also has highlighted the newlinesignificance of combined treatments (Blue irradiation and PEF) in providing newlineenhanced ef