Description of Transport Mechanism During the Elimination of Copper (II) from Wastewaters Using Supported Liquid Membranes and ACORGA M5640 as Carrier

摘要

The kinetics of copper facilitated transport through a\udflat-sheet supported liquid membrane is investigated, using\udthe commercially available oxime Acorga M5640 as\udionophore, as a function of hydrodynamic conditions,\udstripping phase composition, concentration of copper(II),\udand pH of the source phase and carrier concentration in the\udmembrane phase. The performance of the system is also\udcompared using organic diluents of different nature (aliphatic\udor aromatic) and against other available oxime extractants\ud(LIX 860, LIX 622, LIX 973N and LIX 84-I). A model is\udpresented that describes the transport mechanism, consisting\udof diffusion through source side aqueous diffusion layer,\uda fast interfacial chemical reaction, and diffusion carrier and\udits metal complex through the organic membrane. The\udorganic membrane diffusional resistance (¢org) and aqueous\uddiffusional resistances (¢aq) were calculated from the\udproposed model, and their values were 9.3 10-7 and 46565\uds/cm, respectively. It was observed that the copper flux\udacross the membrane tends to reach a plateau at\udhigh concentration of copper or low concentration of H+\udowing to carrier saturation within the membrane and leads\udto a diffusion-controlled process. The values of the\udapparent diffusion coefficient (Dorg\uda) and limiting metal\udflux (Jlim) were calculated from the limiting conditions and\udfound to be 5.2 10-11 and 1.9 10-9 mmol/cm2 s,\udrespectively. The values of the bulk diffusion coefficient\ud(Db,org) and diffusion coefficient (Dorg) calculated from the\udmodel were 4.8 10-10 and 1.3 10-10 cm2/s, respectively.\udThe method had proven its feasibility to recover\udcopper(II) from wastewaters.