Aqueous two-phase extraction of lead from contaminated aqueous solutions

Abstract

Aqueous two-phase extraction is an ecologically safe method for heavy metal recovery and regeneration from contaminated aqueous solutions. Investigation has been carried out experimentally for the extraction of lead from aqueous solutions using Polyethylene Glycol 1500-Ammonium sulfate two-phase system. The extracting agent used is sodium chloride. Aqueous two-phase extraction experiments for Pb(II) have been performed in batch mode according to the central composite design under Response Surface Methodology. The effect of independent parameters as to the extractant concentration, initial salt solution pH, and initial salt phase metal concentration on the extraction efficiency has been studied experimentally. The results indicate that all the three independent parameters studied have significant effect on extraction efficiency. A second-order polynomial model has been used to fit the dependent variable in the experimental range of parameters. The maximum extraction efficiency obtained from the model is about 51% atinitial salt solution pH of 2.8, NaCl concentration of 49.9mmol/Land initial salt phaselead concentration of 9.8 mg/L. This is in agreement with the results obtained from the experiment conducted at optimum conditions.

Extraction of Lead Ions and Partitioning Behavior in Aqueous Biphasic Systems Based on Polyethylene Glycol and Different Salts

“…The highest extraction efficiency of 74.7% was observed for the ATPS containing (NH 4 ) 2 SO 4 . Compared with the previous studies summarized in Table 1, this result is significantly higher than that for other ATPS based on polyethylene glycol 24,25 but lower than some ATPS based on octyl phenol ethoxylate. 23 The second-highest extraction was achieved for the MgSO 4 system.…”

“…To the best of our knowledge, there is only one report on using aqueous biphasic systems based on polyethylene glycol, namely, PEG1500/(NH 4 ) 2 SO 4 and PEG1500/ NaCl, to extract lead ions. 25 The authors reported that the maximum extraction yield was 51.8%.…”

“…In addition, Kaustab Ghosh et al studied the separation of no-carrier-added (NCA) 203 Pb (lead radionuclide) from proton irradiated nat Tl 2 CO 3 target and found that about 60% of NCA 203 Pb was extracted by using an ionic liquid, 1-butyl-3-methylimidazolium chloride ([bmim]Cl), and K 2 HPO 4 salt ATPS system. To the best of our knowledge, there is only one report on using aqueous biphasic systems based on polyethylene glycol, namely, PEG1500/(NH 4 ) 2 SO 4 and PEG1500/NaCl, to extract lead ions . The authors reported that the maximum extraction yield was 51.8%.…”

Optimizing the extraction of cobalt ions under response surface methodology and without organic solutions

“…The initial concentration of the salt phase was 9.8 g/L. [46] Shahrokhi et al investigated copper extraction in aqueous two-phase systems using polyethylene glycol-zinc sulphate in the presence of ammonium thiocyanate extractant. According to the reports provided by the design of the central composite experiment, the highest extraction efficiency of copper ions was obtained under the specified conditions of pH = 4.7, the molecular weight of polyethylene glycol 6000, the concentration of polyethylene 20, and the salt concentration of 15, 93.3%.…”