The use of pulsed electric fields for biofouling prevention and for medical applications

Summary form only given. Experimental studies of the effect of microsecond electric fields on aquatic nuisance species have shown that controlled stress can be induced in these macro-organisms. The effect is assumed to be due to an “electric breakdown” of the outer cell membranes, caused by charging the membrane to values far in excess of the resting voltage. Applications of this effect are the prevention of biofouling (attachment of aquatic nuisance species to surfaces), and debacterialization of liquids. In field experiments it could be shown that pulsed electric field filters at the entrance of cooling water systems prevent biofouling with electric fields as low as 1 kV/cm. The electrical energy consumption was 1 kWh for the treatment of 50000 gls of tidal water. Experiments with the goal to explore the effect of electric fields on the settlement of Zebra mussels, a nuisance species which has caused extensive biofouling problems in fresh water environments, are under way in the River Bend Nuclear Plant on the Mississippi River in St. Francisville, LA. Laboratory experiments in the PERI labs at Old Dominion University have concentrated on basic studies on the effect of pulsed electric fields on cells. A simple electrical equivalent circuit of a biological cell indicated that a reduction in pulse duration from microseconds to nanoseconds should shift the location of the cell damage from the outer membrane to the nucleus. Experiments on the survivability and electric field induced change in morphology of cancer cells have proven this hypothesis