Abstract

The applicability of an alternative wastewater disinfection concept based on the pulsed electric field (PEF) treatment is tested with molecular biology techniques using clinical wastewaters.  Hospital wastewater was treated with the PEF technology. The inactivation efficiencies of bacteria were successfully monitored with real-time polymerase chain reaction (PCR). As the differentiation between living and dead bacterial cells is important for the determination of the disinfection efficiency, propidium monoazide (PMA) was applied. PMA selectively penetrates cells with compromised membranes and intercalates into the DNA inhibiting a subsequent PCR amplification.

The rates of reduction were examined for specific pathogens and wastewater populations using PCR-denaturing gradient gel electrophoresis. The results showed that the main part of the bacterial population could be inactivated efficiently with the PEF treatment. Moreover, it was demonstrated that naturally occurring nuclease activities were not affected by the PEF treatment in contrast to a thermal treatment.  The results indicated that the PEF treatment is an appropriate alternative disinfection concept for the treatment of clinical wastewaters and surpass the disadvantages of other disinfection methods. With the use of propidium monoazide for live–dead distinction, a new concept could be developed for the evaluation of disinfection methods.

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