Kinetics of ozonation of 2-mercaptothiazoline in an electroplating solution

The reaction kinetics of ozonation of 2-mercaptothiazoline (2-MT) in the acid-based electroplating solution of the printed wiring board industry is studied. The substrate prescription of a typical 19 electroplating solution is with [CuSO4.5H(2)O] of 200 g(.)L(-1), [H2SO4] of 60 g(.)L(-1), [Cl-] of 0.03 g(.)L(-1), and pH of 0.18-0.42. Multistep reaction kinetics in terms of ozone, 2-MT, and total organic carbons is proposed to describe the ozonation progress of 2-MT. The enhancement effect of chemical reactions on the ozone gas-liquid mass transfer is considered along with the reaction kinetics. The proposed ozonation kinetics is useful for the treatment of 2-MT via ozonation in the electroplating solution of the printed wiring board industry. The removal of the aged organic additives such as 2-MT can assist the recovery and reutilization of the discarded aged electroplating solution.