Study of new organophosphorus derivates carriers on the selective recovery of M (II) and M (III) metals, using supported liquid membrane extraction

This paper studies different organophosphorus extractants for the selective recovery of metal ions such as Cu (II), Co (II), Ni (II), Pb (II), Fe (III), Cd (II) from effluents resulting from the metal finishing at the time of industry process. In a first step, a commercial extractant such as di(2-ethylhexyl)phosphoric acid (D2EHPA) was used as carrier for SLM extraction. Combining D2EHPA and TOPO (tri-octylphosphine oxide) leads to enhanced extraction of Cu (II), Ni (II) and Co (II). The influence of other critical parameters such as pH, ionic strength and mass transfer resistance of the feed was investigated as well as the diffusion of metal ions and membrane permeation. D2EHPA showed good extraction efficiency for Pb (II) (91%) in the mixture, whereas it is lower for Cu (II) (9%). When TOPO was added to D2EHPA, the extraction efficiency of copper increases up to 57%. In a second step, new organophosphorus extractants, synthesized by microwave irradiation, were tested in SLM extraction of metal ions. Di[p-(1,1′,3,3′-tetramethylbutyl)phenyl] phosphoric acid (DOPPA) and 1,12-(4,9-dioxatrisdecanyl)diphosphonic acid (DOTDDA), selectively extracted Cu (II) and Co (II) (100%) from Fe (III), Cd (II), Pb (II) and Ni (II) in the mixture (0%), whereas methylenediphosphonic acid (MDPA) is a good carrier for Cd (II) (83%), Pb (II) (69%) and Ni (II) (63%) extraction. However 1,13-diamino-4,7,10-trioxatridecanyltetramethylene phosphonic acid (DATOMPA) is useful for extraction of trace metals (Fe (III); 72%). For a selective extraction of Co (II) and Cu (II) from other metals, DOPPA shows the highest extraction efficiency for these two cations, whereas the rest of heavy metals tested are not extracted.