Effect of solution electric conductivity on surfactant treatment using nanosecond pulsed powers

Development of the treatment technology of household effluent and industrial wastewater is imperative for environment conservation. In this study, a solution of persistent surfactant: nonylphenol ethoxylate was treated by using streamer discharges generated with nanosecond pulsed powers. The effects of configuration of water treatment system and of electric conductivity of the surfactant solution on the treatment were investigated. The conductivity was changed by amount of KCl (potassium chloride) added in the surfactant solution. Decolorization of indigo carmine solution with eight inner electrodes system was faster than one inner electrode system. In the treatment experiment, the dependence of the surfactant treatment on the conductivity was not definite. Because a chemical reaction would happen with potassium hydroxide and a surfactant, the effects of solution conductivity on treatment was studied for indigo carmine solution instead of surfactant solution. Decolorization of indigo carmine solution became slow as the conductivity increased. However, the difference of decolorization ratio of indigo carmine solution on conductivity was small. This result shows that this treatment method was hardly affected by the conductivity. Therefore, in practical treatment for drainage water, this method would be more effective than the treatment method using underwater discharges which is easily influenced by the solution conductivity.