Electrocatalytic Oxidation Of Coking Wastewater With Pulse Electrolysis

In China, the steel industry plays an important role in the national economy, and itsdevelopment promotes the steady growth of the national economy. In addition, the rapiddevelopment of the steel industry has also led to the continuous expansion of the cokingproduction. However, the coking wastewater generated in the coking process will causeserious environmental pollution. Coking wastewater is toxic and complicated which isdifficult to treat. In recent years, the problem of treatment of coking wastewater has receivedwidespread concern. The treatment technology of coking wastewater is relatively backward inour country, an efficient and economical way process is to be urgently exploited and utilized.The traditional treatment of coking wastewater by electrochemical oxidation useddirect current as the power supply device. Electrochemical oxidation is restricted duringpractical application because of large consumption of energy. A low-voltage pulse-electrolysis which has the low energy cost was developed in this research.In this paper, we builted an low-voltage pulse system based on electrochemical oxidationto treat coking wastewater from the Wuhan Iron and Steel Plant. During the present work, theTi/RuO2-IrO2-SnO2electrode was used as the working anode and the Ti electrode was used asthe working cathode. By test method for single factor, effects of the degradation of cokingwastewater in different experimental conditions including the initial pH value of wastewater,concentration of NaCl as the electrolyte, voltage of pulse, frequency of pulse and duty ratio,was elucidated respectively. The experimental results indicated that after electrolysis of4hours under the optimal experimental condition of initial pH3, concentration of NaCl0g/L,voltage of pulse20V, frequency of pulse7kHz and duty ratio0.73, the removal efficiency ofCOD was83.52%, and NH3-N levels close to zero.GC-MS was applied to detect the organic compounds in the degradation of thecoking wastewater. Under the same voltage, initial pH, concentration of NaCl andelectrolysis time, the pulse power supply was nearly one-tenth of the direct current powersupply for energy consumption.