Removal of Cyanides in Wastewater by Pulsed High Voltage Discharge

Removal of cyanides by the pulsed discharge plasma using a needle-plate reactor has been investigated. Effects of some factors were studied, including treatment modes, pH values, treatment time, and bubbling gases. The results of experiment indicate that the removal efficiency of cyanide increased greatly when air or nitrogen was injected into the reaction region during the discharge process, and was higher with the addition of air than the addition of nitrogen. The pH value was an important factor that affected the removal rate of cyanide. At a pH of 9, a highest removal rate of 99% was achieved after discharge 120 min. The specific energy consumption for the discharge reactor is 31.25kWh/m³.