A membrane process for metal recovery from aqueous solutions was studied. Metal ions diffused from the feed compartment to the stripping compartment through an hybrid Donnan dialysis which consists to combine two ion exchange membranes with solvent impregnated resin (SIR). The aim of this work is to study the recovery of Pb(II), Ag(I) and Cu(II) from nitrate solutions by using SIR combined with classical Donnan dialysis. The resin has been prepared by impregnating the Amberlite XAD-4 using three different extractants namely: di-2-ethyl hexyl phosphine acide (D<sub>2</sub>EHPA), tris-octyl phosphine oxide (TOPO) and Diphenylthiourea (DPT). Experiments were performed as a function of nature of the extractant impregnated on the XAD-4 resin as well as the concentration in the resin phase, the stripping pH, the concentration ratio of metal ions in the feed compartment and the nature of the counter ions in strip compartment. The results show that the D2EHPA is the better extractant for the metal ions used in this work, and it’s shown a good selectivity for the separation between ions
El-Abed is one of the largest historical and abandoned mining operations for Pb–Zn deposits in northwestern Algeria, leaving large amounts of mining wastes accumulating under the influence of wind erosion. This study aims to verify the concentrations and sources of heavy metals for fifty-six (56) surface samples of environmental media (soil, sediments and mining residues).Chemical analyzes were performed using an optical emission spectrophotometer. A set of environmental quality indicators and multivariate statistical methods with geographic information system was obtained. In this study the mean values of the concentrations of trace metals are: (As = 30,82), (Pb = 1219,27), (Zn = 2855,94), (Cu = 5,3),mg/Kg, and the order as following : Zn > Pb > As > Cu. Based on these results, all trace metals except Copper (Cu) bypassed the the Geochemical background value in the Earth's crust. The results of the multivariate census indicated that there is a strong relationship for pollution indicators for trace elements lead (Pb), zinc (Zn) and arsenic (As). This factors indicate that they are from human sources, and a weak relationship for pollution indicators for trace elements copper (Cu), which is a natural source. Using Geographic Information System and based on spatial distribution maps, many hotspots have been identified. All sampling sites indicate general pollution, poor site quality and environmental hazards.
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