Transport of chromium(VI) through a supported liquid membrane containing tri-n-octylphosphine oxide

Journal Article · Tue Sep 01 04:00:00 EDT 1998 · Separation Science and Technology

DOI:https://doi.org/10.1080/01496399808545037· OSTI ID:292994

Huang, T C; Huang, C C; Chen, D H ^[1]

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1. National Cheng Kung Univ., Tainan (Taiwan, Province of China). Dept. of Chemical Engineering

In this study the transport of chromium(VI) from aqueous solutions of pH 2--4 through a supported liquid membrane (SLM) with tri-n-octylphosphine oxide (TOPO) dissolved in kerosene as a mobile carrier was investigated. The transport flux of Cr(VI) increased with an increase in the concentrations of Cr(VI) in the feed phase and of TOPO in the membrane phase, but with a decrease in pH of the feed phase. Considering the equilibria of various Cr(VI) species in the aqueous phase and of the Cr(VI)-TOPO complexes formed in the membrane phase, a permeation model including the aqueous film diffusion of HCrO{sub 4}{sup {minus}} and Cr{sub 2}O{sub 7}{sup 2{minus}} toward the membrane, the interfacial chemical reaction between them and TOPO, and the membrane diffusion of the Cr(VI)-TOPO complexes ({ovr H{sub 2}CrO{sub 4}{center_dot}(TOPO)} and {ovr H{sub 2}Cr{sub 2}O{sub 7}{center_dot}(TOPO){sub 3}}) was proposed to describe the transport of Cr(VI) through the SLM. By best fitting the transport flux equations of Cr(VI) with the experimental data using the Rosenbrock method, the apparent mass-transfer coefficients of HCrO{sub 4}{sup {minus}} and Cr{sub 2}O{sub 7}{sup 2{minus}} across the aqueous film, and those of {ovr H{sub 2}CrO{sub 4}{center_dot}(TOPO)} and {ovr H{sub 2}Cr{sub 2}O{sub 7}{center_dot}(TOPO){sub 3}} across the membrane phase, were obtained. This work helps to clarify the transport mechanism of Cr(VI) through an SLM.

• Sponsoring Organization: USDOE
• OSTI ID: 292994
• Journal Information: Separation Science and Technology, Journal Name: Separation Science and Technology Journal Issue: 13 Vol. 33; ISSN 0149-6395; ISSN SSTEDS
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
54 ENVIRONMENTAL SCIENCES
CHROMIUM
EXPERIMENTAL DATA
MATHEMATICAL MODELS
MEMBRANE TRANSPORT
SUPPORTED LIQUID MEMBRANES
SURFACE WATERS
TOPO
WASTE WATER
WATER POLLUTION CONTROL
WATER TREATMENT