Extraction Equilibria of Copper(II) with D2EHPA in Kerosene from Aqueous Solutions in Acetate Buffer Media

Abstract

Extraction equilibria of copper(II) from aqueous acetate buffer solutions with di-(2-ethylhexyl)phosphoric acid (D2EHPA) dissolved in kerosene and the stripping equilibria were investigated. Results showed that acetate ions can greatly improve the copper(II) extraction efficiency. The distribution coefficients were significantly dependent on the concentration of acetate ions and the pH value in the aqueous phase because of various mechanisms of extraction and complex formation in the organic phase. With the initial pH value of 4.44 and the acetate ion concentration of 0.18 mol·L-1, the maximum distribution coefficient was observed. In addition, mechanisms of copper(II) extraction in acetate buffer media were established. In the stripping process, the ability to back-extract copper(II) from the organic phase is HCl > H2SO4 > H3PO4.

Extraction of Cu(II) from aqueous solutions by vegetable oil-based organic solvents

“…2). This suggests that D2EHPA, an organophophorus acid, is a highly effective extractant for Cu(II) as reported by Ren et al [12] and Gherrou et al [13]. Being a cation extractant, D2EHPA extracts Cu(II) by a cation exchange process between Cu(II) from the aqueous phase and H + derived from D2EHPA in the organic phase [8].…”

“…The extractant acts as an active component to extract specific metal ions, while the diluent controls the solvent conditions such as the hydrophobicity or water content of the region around the extractant molecules, which can affect the extractability of the extractant molecules [9,10]. Among the various types of extractants, di-2-ethylhexylphosphoric acid (D2EHPA) has been reported as an effective extractant for the separation of Cu(II) from aqueous solutions [11][12][13]. The application of D2EHPA in the removal of other metal ions such as Cd(II) [14], Zn(II) [15], Fe(III) and Ti(IV) [16], as well as other dye stuff [17] from aqueous solutions has also been reported.…”

Removal of copper and zinc from aqueous solutions and industrial effluents using emulsion liquid membrane technique

“…When the initial pH of the aqueous phase equals 4.44, a maximum distribution coefficient of 186 occurred for copper solution which is reported. [31] The pH of the aqueous solution depends on the ratio of acetic acid and sodium acetate in the buffer solution. At lower pH, the media becomes more acidic, more H + ions present in the aqueous phase favors the formation of Cu 2+ from CuR 2 and metal is released from the organic phase to aqueous phase.…”

Base Metal Ion Extraction and Stripping from WEEE Leachate by Liquid-liquid Extraction

“…Using H 2 SO 4 as stripping agent is entirely accepted among several researchers for metal extraction by the dimeric carrier in aliphatic solvents while exceptionally it is reported that HCl efficiency for stripping of copper extraction system is preferred over H 2 SO 4 . [28][29][30][31]…”