Emulsion liquid membranes for wastewater treatment. Equilibrium models for some typical metal-extractant systems

Journal Article · Wed Jun 01 04:00:00 EDT 1994 · Environmental Science and Technology; (United States)

DOI:https://doi.org/10.1021/es00055a018· OSTI ID:7165172

Raghuraman, B; Tirmizi, N; Wiencek, J ^[1]

---

1. Rutgers Univ., Piscataway, NJ (United States)

Emulsion liquid membranes are capable of extracting metals from dilute waste streams to levels much below those possible by equilibrium-limited solvent extraction. Binary equilibrium data are reported for copper, nickel, and zinc with extractants that can be used in emulsion liquid membrane formulations. Predictive models that incorporate aqueous-phase nonidealities and all aqueous-phase ionic reactions have been developed. For the Cu-LIX and Zn-D2EHPA systems, a single value for the equilibrium constant (K) is accurate over a large range of pH and ionic strength. For the Ni-D2EHPA system, an average single K value was obtained for loadings (fraction of D2EHPA dimers complexed to the metal in the organic phase) less than 0.1. At higher loadings, the organic-phase nonidealities become significant, and the equilibrium constant was fitted as an exponential function of the loading. Emulsion liquid membrane extractions of Cu, Ni, and Zn from aqueous phases were successfully carried out. The effects of various parameters such as mixing speed, stripping reagent concentration, and extractant concentration on the extraction process are reported. 36 refs., 10 figs., 1 tab.

• OSTI ID: 7165172
• Journal Information: Environmental Science and Technology; (United States), Journal Name: Environmental Science and Technology; (United States) Vol. 28:6; ISSN ESTHAG; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400105* -- Separation Procedures
400201 -- Chemical & Physicochemical Properties
COLLOIDS
COPPER COMPOUNDS
DISPERSIONS
EMULSIONS
EQUILIBRIUM
EXTRACTION
HYDROGEN COMPOUNDS
LIQUID WASTES
MANAGEMENT
MEMBRANES
NICKEL COMPOUNDS
OXYGEN COMPOUNDS
PH VALUE
PROCESSING
SEPARATION PROCESSES
TRANSITION ELEMENT COMPOUNDS
WASTE MANAGEMENT
WASTE PROCESSING
WASTE WATER
WASTES
WATER
ZINC COMPOUNDS