Electrochemical reduction and kinetic analysis of oxidized mercury in wastewater by choosing titanium plate as cathode

Mercury is one of the important industrial resources, however, because the Minamata Convention restricts the exploitation of mercury resources, it is necessary to efficiently recycle mercury. In order to realize the resource utilization of mercury, the electrochemical method is used to remove the oxidized mercury in the liquid phase and collect the mercury resources. In this study, a titanium plate was used as a cathode to study the reduction of oxidized mercury. Through electrochemical characterization, it can be determined that the oxidized mercury is finally reduced to Hg 0 . The reduction efficiency of Hg 2+ can reach 90% after 24 h of electrolysis under certain conditions. The effects of reaction time, current density, stirring rate, electrode spacing and initial Hg 2+ concentration on the reduction efficiency were also studied. The optimal conditions can be obtained through research: current density 10 mA/cm 2 , no stirring, electrode spacing 20 mm, and electrolyte concentration 10 mg/L HgSO 4 -10% H 2 SO 4 50 mL. The kinetic analysis shows that this reaction accords with the first-order reaction kinetics.