Electrochemical characterization of gold mining wastewater for recovery of mercury using electrochemical method

Abstract

An experimental study to determine optimum operating conditions for mercury recovery from gold mining wastewater has been conducted. Electrochemical characterization of gold mining wastewater was carried out by using steady-state polarization experiment in a batch system. The polarization curves obtained were then utilized to determine the optimum operating conditions. The polarization experiments were conducted by an electrochemical cell with two electrodes of copper (Cu), carbon (C), or stainless steel (SS) and an electrolyte solution of the wastewater. Variations of electrodes used were pairs of copper (Cu), carbon (C) and stainless steel (SS) which were arranged randomly. To obtain the polarization curves, the electrical potentials between 0 V and 3 V were applied and its corresponding currents were recorded at an interval potential of 0.1 V. The highest current density was achieved on electrode pairs of stainless steel-carbon (SS-C) and carbon-carbon (C-C). This is an early indication that the most optimum electrode pairs for mercury recovery possibly are SS-C and C-C. EDX analysis confirmed the presence of mercury in the deposited materials, this leads to a conclusion that mercury can be deposited on to carbon electrode from the wastewater using electrochemical method which then eventually it can be recovered.