Utilization of nickel-electroplating wastewaters in manufacturing of photocatalysts for water purification

A new route of purification/revalorization of nickel electroplating wastewaters is proposed. It is shown that chemical treatment of different nickel-electroplating wastewaters with aqueous dispersion of layered structure amorphous potassium polytitanate (PPT) successfully removed the nickel from the effluents. Moreover, the resulting solid products, obtained with optimal PPT doses, showed excellent and consistent photocatalytic properties in the visible range of solar radiation, which are independent on the characteristics of the wastewater i.e. pH, nickel contents or the presence of other heavy metals. On the other hand, after proper dilution, the resulting treated effluents can be returned to the municipal wastewater collectors. The mechanisms of the processes taking place during the treatment are analyzed.