Operational Limits of the Bulk Hybrid Liquid Membranes Based on Dispersion Systems

Andreea Ferencz Dinu; Alexandra Raluca Grosu; Hussam Nadum Abdalraheem Al-Ani; Aurelia Cristina Nechifor; Szidonia-Katalin Tanczos; Paul Constantin Albu; Mihaela Emanuela Crăciun; Mihail-Răzvan Ioan; Vlad-Alexandru Grosu; Gheorghe Nechifor

doi:10.3390/membranes12020190

Operational Limits of the Bulk Hybrid Liquid Membranes Based on Dispersion Systems

Membranes (Basel). 2022 Feb 5;12(2):190. doi: 10.3390/membranes12020190.

Affiliations

¹ Analytical Chemistry and Environmental Engineering Department, University Politehnica of Bucharest, 011061 Bucharest, Romania.
² Chemical Industries Department, Institute of Technology, Middle Technical University, Al Zafaraniyah, Baghdad 10074, Iraq.
³ Department of Bioengineering, University Sapientia of Miercurea-Ciuc, 500104 Miercurea-Ciuc, Romania.
⁴ Radioisotopes and Radiation Metrology Department (DRMR), IFIN Horia Hulubei, 023465 Măgurele, Romania.
⁵ Department of Electronic Technology and Reliability, Faculty of Electronics, Telecommunications and Information Technology, University Politehnica of Bucharest, 061071 Bucharest, Romania.

Abstract

Liquid membranes usually have three main constructive variants: bulk liquid membranes (BLM), supported liquid membranes (SLM) and emulsion liquid membranes (ELM). Designing hybrid variants is very topical, with the main purpose of increasing the flow of substance through the membrane but also of improving the selectivity. This paper presents the operational limits of some kind of hybrid membrane constituted as a bulk liquid membrane (BLM), but which works by dispersing the aqueous source (SP) and receiving (RP) phases, with the membrane itself being a dispersion of nanoparticles in an organic solvent (NP-OSM). The approached operational parameters were the volume of phases of the hybrid membrane system, the thickness of the liquid membrane, the working temperature, the flow of aqueous phases, the droplet size of the aqueous phases dispersed across the membrane, the nature and concentration of nanoparticles in the membrane, the pH difference between the aqueous phases, the nature of the organic solvent, the salt concentration in the aqueous phases and the nature of transported chemical species. For this study, silver ion (SI) and p-nitrophenol (PNP) were chosen as transportable chemical species, the n-aliphatic alcohols (C₆…C₁₂) as membrane organic solvents, 10-undecenoic acid (UDAc) and 10-undecylenic alcohol (UDAl) as carriers and magnetic iron oxides as nanoparticles dispersed in the membrane phase. Under the experimentally established operating conditions, separation efficiencies of over 90% were obtained for both ionic and molecular chemical species (silver ions and p-nitrophenol). The results showed the possibility of increasing the flow of transported chemical species by almost 10 times for the silver ion and approximately 100 times for p-nitrophenol, through the appropriate choice of operational parameters, but they also exposed their limits in relation to the stability of the membrane system.

Keywords: hybrid design liquid membranes; liquid membranes; membrane flux; membrane selectivity; membrane system stability; operational parameters; p-nitrophenol transports; silver ion transport.