Treatment of Thiocyanate Wastewater by Iron-Carbon Microelectrolysis-Fenton Process and Study of Its Mechanism
Thiocyanate in industrial wastewater is a toxic substance that jeopardizes the environment and human health,and its characteristics such as difficult degradation increase the difficulty of wastewater treatment.In the article,the efficient pretreatment of thiocyanate(SCN-)wastewater was achieved by coupling iron-carbon micro-electrolysis with Fenton oxida-tion and optimizing the process parameters.Through the methods of one-factor experiment and kinetic analysis,it was deter-mined that the SCN-concentration could be reduced from 508.3 mg/L to 16.8 mg/L by controlling the pH of the reaction system between 3 and 4 for 90 min at the aeration of iron-carbon micro-electrolysis of 1.5 L/min,removing the water at the end of the reaction and adding 8 mL/L of 30％H2O2 solution,and magnetically stirring the reaction for 30 min.The SCN-concentration was reduced from 508.3 mg/L to 16.8 mg/L with a removal rate of 96.7％,and the SCN-was completely removed by continuing the reaction for 60 min.The small amount of OH generated by micro-electrolysis oxidized part of Fe2+to Fe3+,formed the complex Fe(NCS)63-with SCN-,which was oxidized to form a trace amount of CN-,which was further mineralized to NH3 and CO2.The large amount of OH generated in the Fenton stage oxidized the remaining CN-and all SCN-to CNO-,and finally mineralized to NO3-and N2.This study provides a new pretreatment method for thiocya-nate-containing wastewater,revealing the mechanism of the enhanced pretreatment of thiocyanate by iron-carbon Fenton technology.mechanism of pretreatment of thiocyanate.
万方数据
维普
