Process and model of a chemically buffered supported liquid membrane system for cobalt extraction

Supported Liquid Membrane Systems (SLMS) have previously been shown to be effective mimics of active transport of ions. This can be controlled through use of thin film, fixed site carrier membranes on the external surfaces of an SLMS, to encapsulate it. This film must exhibit selective facilitated transport characteristics. The authors demonstrate this entrapping concept here by incorporating their previously successful SLMS with a thin film coating of a cation exchange membrane, Nafion(R) 124. Successful experiments for nickel transport were conducted in a recirculating dialysis unit. The authors also attempted to use fixed site carrier membranes; an ethylene-acrylic acid ionomer. Preliminary data indicates the approach is be sound for some cations, however the data for nickel was not conclusive. The most probable design for biomedical applications appears to be a combination (laminate) system that incorporates supported liquid membranes and highly selective molecularly engineered thin film entrapping membranes utilizing advanced materials technologies.

Enhancing the stability of supported liquid membrane in phenols removal process by hydrophobic modification

It is essential to remove acetic acid from the biomass hydrolysate during the biorefinery process. The product yield can be effected by the acetic acid due to it inhibition to the microorganism used during the fermentation. Supported liquid membrane (SLM) can be used to remove the acetic acid. The membrane support plays important role in the SLM process. However, due to the use of the commercial membrane support, lack of studied was conducted on the fabrication of custom made membrane support for the SLM process. In the current study, two level full factorial design was employed to screen three fabrication factors during preparation of polyethersulfone-graphene membrane support via vapor induced phase separation technique. The factors screened were temperature of water bath (A) (30-60 °C), exposure time (B) (10-60 s) and air humidity (C) (70-90 RH%). The response was evaluated based on the extraction percentage of the acetic acid from 10 g/L aqueous acetic acid feed solution. All three main factors were significant to the SLM performance. Air humidity factor (C) gave the highest contribution of 28.96% among the main factors. In term of the interaction between factors, water bath temperature (A) and exposure time (B) give the most significant effect with 45.01% percentage of contribution. The highest extraction percentage of the acetic acid using SLM system was 75.95% using the membrane prepare at 30 °C water bath temperature, 10 s exposure time and 70% air humidity.

A supported liquid membrane is developed for the separation of Cd from either high in salinity or acidity aqueous media. The membrane consisted of a durapore (polyvinylidene difluoride) polymeric support impregnated with a 0.5 M Aliquat 336 solution in decaline. The effect of carrier concentration, organic solvent and feed and receiving solutions on the metal permeability is studied. This system allows the effective transport of trace levels of Cd through the formation of CdCl42−, which is the predominant species responsible for the extraction process, in both NaCl and HCl solutions. The supported liquid membrane system in a hollow fibre configuration allows the enrichment and separation of trace levels of Cd from spiked seawater samples, facilitating the analytical determination of this toxic metal.

Transport of amino compound relevant to biology, d-glucosamine, was carried out with a supported liquid membrane using a lipophilic aldehyde, 4-octadecyloxybenzaldehyde, as a carrier. In the present membrane transport system, a reversible organic reaction, Schiff base formation reaction, between amino group in d-glucosamine and aldehyde group in carrier was utilized as a molecular recognition reaction.

The rare earth metals are high-tech elements of the periodic table and have extensive demand for their utilization on making high-end materials. Solvent extraction (SX) and supported liquid membrane (SLM) technology are key approaches in hydrometallurgical operation for effective extraction of rare earth metal(s) from numerous complex aqueous solutions. The major challenge and/or issue encountered is process selectivity especially on the separation of either of the rare earth metal(s) in the presence of others. The similar chemical property of the elements of lanthanides as well as actinides prevents effective and selective separation of individual rare earths, though high separation factor has been attained, while employing novel organic reagents through above techniques. Both in SX and SLM process, the extractant plays a vital role on achieving clean and effective separation of each of the RE metals. The most common reagents such as commercial organophosphorus reagents and oxidic reagents in general are applied for extraction of REEs; however, the noble green solvent like ionic liquids (ILs) appears to be more promising in these days. The basic principle, extraction chemistry, separation behaviour, loading ability of extractants and extraction isotherm (both in extraction and stripping) are discussed to ascertain the transportation behaviour of RE metals from one to other phase (aqueous to organic and vice versa). This book chapter is an attempt to give the insight about the adoption of SX and SLM methodologies in day by day progress in metallurgical extraction processes especially on separation of rare earth metals including lanthanides, actinides and other light rare earth metals (Scandium and Yttrium).

The transport of Ga(III) from chloride solution by supported liquid membrane (SLM) using organophosphorus acids as carriers was studied and compared with solvent extraction results. The diffusion coefficient, permeability coefficient and mass transfer resistance for both processes were analyzed by investigating various parameters, such as flow pattern, flow rate, pH, Ga(III)/extractant concentration and temperature. Under optimized conditions, the extraction percentage of 97.0% and permeability coefficient of 9.22 × 10−6 m/s was achieved for SLM process. Kinetic modeling was proposed to determine the mass diffusion coefficient of Ga(III) complex across the membrane and stability of this SLM system was also examined.

Transport of salicylic acid through supported liquid membrane based on ionic liquids

Direct determination of chlorophenols in water samples through ultrasound-assisted hollow fiber liquid–liquid–liquid microextraction on-line coupled with high-performance liquid chromatography

Electrokinetic migration of acidic drugs across a supported liquid membrane

Electromembrane extraction of peptides

The permeation of Cd(II) ions from aqueous phosphate medium through a supported liquid membrane (SLM) consisting of a flat disc cellulose nitrate membrane immobilizing a Cyanex-302 in kerosene as carrier has been investigated. The transfer of Cd(II) ions has been studied as a function of the stirring rate, the concentration of the extractant, the stripping solution, and the phosphate concentration in the feed. The experimental results are evaluated in terms of the permeation rate, the permeability coefficient, and the enrichment factor. The difference in the kinetic behavior of Cd(II), Cu(II), and Zn(II) when mixed together is used to improve the selective separation of Cd(II) by the investigated SLM system. The assessment of the conditions for the use of this system in pollution control of the environment with heavy metals produced from phosphate wastewater streams is discussed.

Short review on liquid membrane technology and their applications in biochemical engineering

Spectroscopic characterization of the interactions between poly(2-(trimethylamino)ethyl methacrylate) chloride and the xanthene dyes, 2′, 7′-difluorofluorescein and 2, 4, 5, 7-tetraiodofluorescein

Modelling and Application of a Pilot-Scale Supported Liquid Membrane Unit for Uranyl Nitrate Extraction