关键词: 金, 电化学, S₂O₃^2-, NH₃

Abstract: Heavy metals in industrial sewage are very serious pollution to the environment, especially to the soil and groundwater which cannot be ignored. So it is important to recover heavy metals from the sewage. At present, electrochemical method is widely used in the recovery of heavy metal elements from sewage. Aiming at the electrochemical corrosion process of gold (Au) in sewage, the electrochemical behavior of gold (Au) at different concentrations of S₂O₃^2- and NH₃ was analyzed by electrochemical test. The results show that S₂O₃^2- and NH₃ mainly affect the cathodic reaction process of gold (Au); with the increase of S₂O₃^2- and NH₃ concentration, the cathodic process changes from the limiting diffusion process to the activation control process; meanwhile, the electrochemical reaction process of gold (Au) no longer changes when the concentration of S₂O₃^2- and NH₃ reaches a certain value.

Key words: gold (Au), electrochemistry, S₂O₃^2-, NH₃