Use of aqueous two-phase PEG-salt systems for the removal of anionic surfactant from effluents

Thermodynamic Investigation of the Aqueous Two-Phase Systems Formed by PEG 400 + Water + Either Sodium Carbonate or Potassium Carbonate at Different Temperatures: Experimental and Correlational Approaches

“…23,24 Its use in ATPSs offers the advantages of rapid formation of two phases and ease of handling due to its low viscosity. 21 Therefore, it is of considerable interest to obtain ATPSs formed by PEG 400 and other salts.…”

“…This information includes the binodal line that separates the biphasic and monophasic regions and the tie-lines that connect the polymer and salt compositions of the two phases in thermodynamic equilibrium. 21,23,24 In ATPS studies, in addition to the information provided by the phase diagram, understanding of the phase separation mechanism requires evaluation of the main parameters that influence the process, including temperature, the nature of the system components, and the tie-line lengths. 23,24,29 In this work, phase diagrams were obtained for the PEG 400 + Na 2 CO 3 + H 2 O and PEG 400 + K 2 CO 3 + H 2 O systems at 283.15, 298.15, and 313.15 K, and the influences of temperature and the cation salt on the segregation process were evaluated.…”

“…Polymer-salt ATPSs are most widely used for preparative-scale extractions. These ternary systems consist of two phases: a top phase enriched with a polymer or a salt and a bottom phase enriched with a different polymer or salt. ,, Although the literature includes several studies of polymer–salt systems containing poly­(ethylene)­glycol (PEG) and inorganic salts, ,,, investigations employing PEG 400 remain scarce. To the best of our knowledge, PEG 400 has only been used with sulfate salts (MgSO 4 , Na 2 SO 4 , and (NH 4 ) 2 SO 4 ). , Its use in ATPSs offers the advantages of rapid formation of two phases and ease of handling due to its low viscosity .…”

“…These ternary systems consist of two phases: a top phase enriched with a polymer or a salt and a bottom phase enriched with a different polymer or salt. ,, Although the literature includes several studies of polymer–salt systems containing poly­(ethylene)­glycol (PEG) and inorganic salts, ,,, investigations employing PEG 400 remain scarce. To the best of our knowledge, PEG 400 has only been used with sulfate salts (MgSO 4 , Na 2 SO 4 , and (NH 4 ) 2 SO 4 ). , Its use in ATPSs offers the advantages of rapid formation of two phases and ease of handling due to its low viscosity . Therefore, it is of considerable interest to obtain ATPSs formed by PEG 400 and other salts.…”

“…The application of an ATPS as a separation method requires construction of a phase diagram, which provides information fundamental for understanding the formation of the ATPS and its characteristics. This information includes the binodal line that separates the biphasic and monophasic regions and the tie-lines that connect the polymer and salt compositions of the two phases in thermodynamic equilibrium. ,, …”