Behavior of hydrophobic ionic liquids as liquid membranes on phenol removal: Experimental study and optimization

Abstract

of hydrophobic ionic liquids as liquid membranes on phenol removal: Experimental study and optimization, Desalination 278(1-3) (2011) 250-258. AbstractRoom temperature ionic liquids show potential as an alternative to conventional organic membrane solvents mainly due to their properties of low vapor pressure, low volatility and they are often stable. In the present work, the technical feasibilities of room temperature ionic liquids as bulk liquid membranes for phenol removal were investigated experimentally. Three ionic liquids with high hydrophobicity were used and their phenol removal efficiency, membrane stability and membrane loss were studied. Besides that, the effects of several parameters, namely feed phase pH, feed concentration, NaOH concentration and stirring speeds on the performance of best ionic liquid membrane were also evaluated.Lastly, an optimization study on bulk ionic liquid membrane was conducted and the maximum phenol removal efficiency was compared with the organic liquid membranes. The preliminary study shows that high phenol extraction and stripping efficiencies of 96.21% and 98.10%, respectively can be achieved by ionic liquid membrane with a low membrane loss which offers a better choice to organic membrane solvents.

A comparative study on the removal of phenol from aqueous solutions by electro–Fenton and electro–persulfate processes using iron electrodes

“…Sampling was carried out at different times, and samples were then centrifuged (6000 rpm for 10 min), and absorbed amounts of the remaining phenol in the samples were measured through direct photometry using UV-Vis spectrophotometry at a wavelength of 500 nm [14]. The efficiency of phenol removal was calculated as follows [15]:…”

Determining Kinetic Constants and Transport Efficiencies at Membrane Interfaces to Optimize the Removal/Recovery of Cu(II) through Lulk Liquid Membranes Containing Benzoylacetone as Carrier

“…Efficiency percentages of Cu(II) transported through the feed/membrane (F/M) and membrane/product (M/P) interfaces (at 24 hours) were calculated from the following equations [22]: (1) (2) … where C fo is the initial concentration of Cu(II) ions in the feed phase and C ft and C pt are the concentrations of Cu(II) in the feed and product phases, respectively, at 24 hours. The carrier-facilitated countertransport of Cu(II) through bulk liquid membranes can be explained by the kinetic laws of two consecutive irreversible firstorder reactions, the removal or extraction reaction (rate constant, k e ) and the recovery or stripping reaction (rate constant, k s ).…”

Kinetic Study of Copper(II) Simultaneous Extraction/Stripping from Aqueous Solutions by Bulk Liquid Membranes Using Coupled Transport Mechanisms

“…For practical reasons, dimensionless reduced concentrations of copper(II) in the feed (Rf = Cft/Cf0), membrane (Rm = Cmt/Cf0), and product (Rp = Cpt/Cf0) phases were used (the sum of Rf + Rm + Rp obviously being unity). In addition, the efficiency of Cu(II) extraction from the feed phase (EE) and of Cu(II) stripping in the product phase (SE), were calculated, at 24 h, from the following equations [24]: EE % 100 (1) SE % 100 (2) where Cf0 is the initial concentration of Cu(II) in the feed phase, and Cft, Cmt, and Cpt are the concentrations of Cu(II) in the feed, membrane, and product phase, respectively, at time t. …”

“…For practical reasons, dimensionless reduced concentrations of copper(II) in the feed (R f = C ft /C f0 ), membrane (R m = C mt /C f0 ), and product (R p = C pt /C f0 ) phases were used (the sum of R f + R m + R p obviously being unity). In addition, the efficiency of Cu(II) extraction from the feed phase (EE) and of Cu(II) stripping in the product phase (SE), were calculated, at 24 h, from the following equations [24]:…”