Recovery of acid and some metals in waste spent solution used in surface cleaning in metal coating (galvanized) process

Within the scope of this master dissertation, the recovery of hydrochloric acid, zinc and iron ions in the waste pickling solutions of metal plating enterprises was investigated. The waste generated as a result of the pickling process not only damages the environment but also causes economic losses. In this context, the waste piclink solution was suplied from the Tekno Bağlantı Elemanları A.Ş. company wich does galvanizing business. The metal ions such as Zn2+ and Fe2+ extracted by solvent extraction method with tri-butyl phosphate (TBP) and di-(2-ethylhexyl) phosphoric acid (HDEHP); On the other hand, HCl(aq) recovery studies were carried out by distillation, membrane distillation and ion exchange resin methods. The recovery of zinc and iron ions increases depending on the phosphate concentration, the optimum recovery is 60% TBP and 60% HDEHP. The recovery of Fe(II) is 99.54% and the recovery of Zn(II) is %77,82 at 60% TBP and the recovery of Fe(II) was 99.72% and the recovery of Zn(II) was 99.32% at 60% HDEHP. In the recovery of HCl(aq), the initial waste picling acid concentration changes from 3.90 M to 4.90 M with ordinary distillation, 5.25 M with membrane distillation (MD) and 5.85 M with ion exchange resin.