High Voltage Underwater Discharge and ITs Application

Summary form only given. A spark discharge has been researched in the past for various applications. A spark discharge in water can produce shock wave, ultraviolet radiation and radical. Destroying kidney stones in human by shock wave is a special application. A spark discharge was generated by applying a pulsed high voltage of V=10~30 kV to electrodes in water. For controlling charged energy in a capacitor bank (30 nF) and discharge frequency, thyratron switch and air gap switch were used. When spark discharge occur in water voltage and current was measured by oscilloscope with high voltage probe and Rogowski coil. As a material of electrodes a tungsten tip and coaxial stainless steel was used. In this study, sewage sludge and freshwater algae was treated by the spark discharge. Sewage sludge is composed of organic materials, bacteria and mostly water. The object of the sewage sludge treatment, reducing water content and destroying sludge bacteria cell membrane, is minimize the final sludge. A measuring method for investigating the treatment result is chemical oxygen demand (COD). Algae in freshwater can cause serious effect on underwater ecosystem and human health. Being on ponds, lakes and dams, if a surrounding condition is good, algae is starting to be active. Algae treatment which was carried with a condition of pulsed spark discharge and pulsed non-spark discharge was compared by electronic microscope.