On the Selective Transport of Nutrients through Polymer Inclusion Membranes Based on Ionic Liquids

Abstract

In the last few years, the use of ionic liquid-based membranes has gained importance in a wide variety of separation processes due to the unique properties of ionic liquids. The aim of this work is to analyze the transport of nutrients through polymer inclusion membranes based on different concentrations of methyltrioctylammonium chloride, in order to broaden the application range of these kinds of membranes. Calcium chloride (CaCl2) and sodium hydrogen phosphate (Na2HPO4) nutrients were used at the concentration of 1 g·L−1 in the feeding phase. The evolution of the concentration in the receiving phase over time (168 h) was monitored and the experimental data fitted to a diffusion-solution transport model. The results show very low permeation values for CaCl2. By contrast, in the case of Na2HPO4 the permeation values were higher and increase as the amount of ionic liquid in the membrane also increases. The surface of the membranes was characterized before and after being used in the separation process by scanning electron microscopy coupled to energy dispersive X-Ray spectroscopy (SEM–EDX) and elemental mapping analysis. The SEM–EDX images show that the polymer inclusion membranes studied are stable to aqueous solution contacting phases and therefore, they might be used for the selective transport of nutrients in separation processes.

Thermophysical Properties and CO2 Absorption of Ammonium-Based Protic Ionic Liquids Containing Acetate and Butyrate Anions

“…The calculated correlation coefficients together with standard deviations, SD are presented in Tables 4 and 5. The standard deviations, SD, were calculated using Equation 5in which Z expt and Z calc are experimental and calculated values, respectively, while n DAT is the number of experimental points: The thermal expansion coefficient, α p , for the ammonium-based protic ionic liquids can be calculated using Equation (6) [28] while the molecular volume, V m can be estimated from Equation (7) in which M is the molar mass of the ionic liquid and N A represents the Avogadro's number [32,36,37]:…”

“…Ionic liquids are low melting salts with typical melting points of below 100 • C. Furthermore, there are countless possible combinations of cations and anions that can yield ionic liquids and this flexibility is utilized to design ionic liquids based on the application. Ionic liquids are used in many applications, such as in chemical reactions and separation processes [3][4][5][6]. In the field of CO 2 capture using ionic liquids, initial work on the CO 2 -ionic liquid system was done in 2001 [7] and, following this discovery, extensive works have been done to explore the absorption of CO 2 in ionic liquids under various operating conditions [8][9][10][11][12][13][14][15].…”

Development and Application of Supported Ionic Liquid Membranes in Microbial Fuel Cell Technology: A Concise Overview

“…To overcome the instability of SILMs in aqueous media/polar solvents, alternative directions in ionic liquid-containing membrane development for double-compartment microbial fuel cells have appeared. These rely on the blending of various ILs and organic polymers, resulting in a polymer-inclusion membrane, and can be regarded as a possible way forward [36][37][38].…”

“…To overcome the instability of SILMs in aqueous media/polar solvents, alternative directions in ionic liquid-containing membrane development for double-compartment microbial fuel cells have appeared. These rely on the blending of various ILs and organic polymers, resulting in a polymer-inclusion membrane, and can be regarded as a possible way forward [36][37][38]. On the other hand, just like in most (filtration) processes where a membrane is employed, chemical and biological fouling of the membrane installed in the bioelectrochemical system is a real threat [26].…”

Immobilization in Ionogel: A New Way to Improve the Activity and Stability of Candida antarctica Lipase B

“…In recent decades, ionic liquids have demonstrated their potential for use as reaction and separation media. For example, in separation applications, they have been used as liquid–liquid biphasic systems [ 1 , 2 ] and as liquid phase in supported liquid membranes and polymer inclusion membranes [ 3 , 4 , 5 ]. In the field of biocatalysis, ionic liquids have been used as free solvent [ 6 , 7 , 8 ], adsorbed [ 9 , 10 , 11 , 12 ], covalently linked to particle enzymes [ 13 , 14 , 15 ], or as polymeric ionic liquids [ 16 ] in enzyme particles, in all cases to create an adequate microenvironment for the enzyme or to improve catalytic efficiency.…”