Less Chemicals and More Power: Pulsed Electric Field-Treatment for Reduction of Microorganisms

Decisions on the implementation of innovative concepts and technologies into automotive pre-treatment lines are regularly marked by uncertainty regarding trade-offs between economic, ecological and technical aspects. Large amounts of water are consumed during the production in car body painting plants. It is hardly possible to avoid that certain microorganisms (MOs) proliferate in process water and pre-treatment bath tanks. If the bacterial load increases too much, the quality of the paint finish is likely to be impaired. Therefore, chemical biocides are regularly used in pre-treatment and dip coating plants. However, repeated use of the same biocides can lead to resistance of some MOs strains. In addition, stricter legislation is gradually withdrawing certain biocides from the market, making it more difficult to obtain approval for newly designed active substances. Hence, conventional decontamination methods might no longer work in the future. The Pulsed Electric Field (PEF)-Treatment is an innovative technology within the field of pre-treatment lines. By applying high voltage pulses (kV range, µs duration), a high field strength is generated in the process fluid, across the cell membrane of the MOs, which permeabilises the cell membrane. As a result, the MOs lose their cell interior (cytoplasm), and most likely die.