Poly(Homopiperazine-Amide) Thin-Film Composite Membrane for Nanofiltration of Heavy Metal Ions

Syed Ibrahim; Mahdi Mohammadi Ghaleni; Arun M Isloor; Mona Bavarian; Siamak Nejati

doi:10.1021/acsomega.0c04064

Poly(Homopiperazine-Amide) Thin-Film Composite Membrane for Nanofiltration of Heavy Metal Ions

ACS Omega. 2020 Oct 26;5(44):28749-28759. doi: 10.1021/acsomega.0c04064. eCollection 2020 Nov 10.

Authors

Syed Ibrahim¹, Mahdi Mohammadi Ghaleni², Arun M Isloor^{1

3}, Mona Bavarian², Siamak Nejati²

Affiliations

¹ Membrane Technology Laboratory, Department of Chemistry, National Institute of Technology Karnataka, Surathkal, Mangalore 575025, India.
² Department of Chemical and Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-8286, United States.
³ Apahatech Solutions LLP, Science and Technology Entrepreneurs Park, National Institute of Technology Karnataka, Surathkal, Mangalore 575025, India.

Abstract

The development of membrane-based technologies for the treatment of wastewater streams and resources containing heavy metal ions is in high demand. Among various technologies, nanofiltration (NF) membranes are attractive choices, and the continuous development of novel materials to improve the state-of-the-art NF membranes is highly desired. Here, we report on the synthesis of poly(homopiperazine-amide) thin-film composite (HTFC)-NF membranes, using homopiperazine (HP) as a monomer. The surface charge, hydrophilicity, morphology, cross-linking density, water permeation, solute rejection, and antifouling properties of the fabricated NF membranes were evaluated. The fabricated HTFC NF membranes demonstrated water permeability of 7.0 ± 0.3 L/(m² h bar) and rejected Na₂SO₄, MgSO₄, and NaCl with rejection values of 97.0 ± 0.6, 97.4 ± 0.5, and 23.3 ± 0.6%, respectively. The membranes exhibit high rejection values of 98.1 ± 0.3 and 96.3 ± 0.4% for Pb²⁺ and Cd²⁺ ions, respectively. The fouling experiment with humic acid followed by cross-flow washing of the membranes indicates that a flux recovery ratio (FRR) of 96.9 ± 0.4% can be obtained.