pH and pCl Operational Parameters in Some Metallic Ions Separation with Composite Chitosan/Sulfonated Polyether Ether Ketone/Polypropylene Hollow Fibers Membranes

Abstract

The development of new composite membranes is required to separate chemical species from aggressive environments without using corrective reagents. One such case is represented by the high hydrochloric acid mixture (very low pH and pCl) that contains mixed metal ions, or that of copper, cadmium, zinc and lead ions in a binary mixture (Cu–Zn and Cd–Pb) or quaternary mixture. This paper presents the obtaining of a composite membrane chitosan (Chi)–sulfonated poly (ether ether ketone) (sPEEK)–polypropylene hollow fiber (Chi/sPEEK/PPHF) and its use in the separation of binary or quaternary mixtures of copper, cadmium, zinc, and lead ions by nanofiltration and pertraction. The obtained membranes were morphologically and structurally characterized using scanning electron microscopy (SEM), high resolution SEM (HR–SEM), energy dispersive spectroscopy analysis (EDAX), Fourier Transform InfraRed (FTIR) spectroscopy, thermogravimetric analysis, and differential scanning calorimetry (TGA-DSC), but also used in preliminary separation tests. Using the ion solutions in hydrochloric acid 3 mol/L, the separation of copper and zinc or cadmium and lead ions from binary mixtures was performed. The pertraction results were superior to those obtained by nanofiltration, both in terms of extraction efficiency and because at pertraction, the separate cation was simultaneously concentrated by an order of magnitude. The mixture of the four cations was separated by nanofiltration (at 5 bars, using a membrane of a 1 m2 active area) by varying two operational parameters: pH and pCl. Cation retention could reach 95% when adequate values of operational parameters were selected. The paper makes some recommendations for the use of composite membranes, chitosan (Chi)–sulfonated poly (ether ether ketone) (sPEEK)–polypropylene hollow fiber (Chi/sPEEK/PPHF), so as to obtain the maximum possible retention of the target cation.

Hydrogen Sulphide Sequestration with Metallic Ions in Acidic Media Based on Chitosan/sEPDM/Polypropylene Composites Hollow Fiber Membranes System

“…For the first challenge, which in our previous studies was only partially solved by using sulfonated polyether–ether–ketones [ 52 , 56 ], a resistant polymer with strongly acidic ionic groups sulfonated ethylene-propylene-diene terpolymer was used (sEPDM), which, as shown in Figure 5 and Figure 6 , was beneficial.…”

“…Chitosan-ionic polymer composite membranes have recently been used as essential elements in fuel cells [ 51 ] and in the separation of certain metal ions [ 52 ].…”

Thorium Removal, Recovery and Recycling: A Membrane Challenge for Urban Mining

“…If we focus on membrane processes, it can be stated that the membrane is a window of a multi-component system ( Figure 5 ), with selective permeability for chemical species of the system [ 173 ]. This membrane allows the separation of the considered system, consisting of a continuous phase (solvent) in which ionic chemical species, molecules and macromolecules are dissolved.…”

Chitosan–sEPDM and Melatonin–Chitosan–sEPDM Composite Membranes for Melatonin Transport and Release

“…The representative ways of delivery, controlled release of the various chemical species of interest, many of which have been studied for melatonin as well, are suggested in Figure 1 [ 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 ].…”

“…Studies related to improving the performance of fuel cell membranes have shown that an effective means of chitosan reticulation can be performed with ionophores with sulfonic groups of the polyether–ether sulfonated ketone type [ 40 ].…”