Pb/Fe SEPARATION AND RECOVERY FROM AUTOMOBILE BATTERY WASTEWATERS BY SELECTIVE ION EXCHANGE

Laboratory scale investigation has been carried out For the optimization of a new process for separation and recovery of Pb/Fe species from automobile battery manufacturing wastewaters. The innovation, based on ion exchange, allows for separation and recovery of the mentioned species by the use of a commercial weak anion resin (Duolite A7 from Rohm&Haas Co, USA), as selective sorbent for the ferric species, and a weak cation resin with carboxylate functionality (Purolite C106 from Purolite Co.,UK) for removal and recovery of lead species. Cl-form anion resin was eluted with real automobile battery wastewaters (pH 3; Fes= 4BV/h; influent Fe concentration: 2 mg/L) for a column throughput exceeding 200 BV (Bed Volumes) with Fe leakage steadily below 0.2 mg/L, (ten times lower the maximum allowable concentration, MAC, for discharge in closed water bodies, enforced by EU legislation). Lead species were removed and recovered on Na/H-form cation resin (pH 6; Fexh=20 BV/h; influent Pb concentration: 4 mg/L) for a column throughput exceeding 15,000 BV at average Pb leakage below 0.03 mg/L (MAC=0.2 mgPb/L). Both sorbents were regenerated by limited amounts of 1M HCl. Specifically, resin Duolite A7 was eluted with 5 BV (Freg=2BV/h), and carboxylate resin was eluted with 30BV