Concurrent Removal of Selenium and Arsenic from Water Using Polyhedral Oligomeric Silsesquioxane (POSS)–Polyamide Thin-Film Nanocomposite Nanofiltration Membranes

Abstract

With stringent regulations regarding the toxic ions selenium and arsenic on wastewater discharge, various industries such as coal mining and power generation are demanding more efficient and effective treatment methods to remove these two ions. Since the performance of commercially available thin film composite nanofiltration (NF) membranes reported so far has a great room for improvement, a thin-film nanocomposite (TFN) NF membrane comprising polyhedral oligomeric silsesquioxane (POSS) with high efficiency was developed for the concurrent removal of selenium and arsenic from aqueous solutions. The resultant NF membrane has a mean effective pore diameter of 0.65 nm, a molecular weight cutoff of 302 Da, and superior pure water permeability of 5.4 LMH/bar with notably high rejections of SeO3 2–, SeO4 2–, and HAsO4 2– toward 93.9%, 96.5%, and 97.4%, respectively. The TFN membranes also exhibit slightly higher rejection performance when a mixed ion solution separation test was conducted. To the best of our knowledge, this is the first reported NF membrane comprising POSS in the selective layer for the concurrent removal of Se and As ions. The promising results achieved in this study provide promising methodology for the development of novel NF membranes to remove other multiple toxic ions from waste streams.

Dendrimeric Thin-Film Composite Membranes: Free Volume, Roughness, and Fouling Resistance

“…Thin film composite (TFC) membranes have been widely used for wastewater treatment and desalination in nanofiltration (NF), 1 reverse osmosis (RO), and forward osmosis (FO) [3][4][5][6][7][8] processes, because of their (i) high water permeance and good selectivity, compared to integrally skinned asymmetric membranes, (ii) simple and fast fabrication process, and (iii) high flexibility in membrane design with independent optimization of selective layers and porous supports.…”

Silsesquioxane‐Containing Hybrid Nanomaterials: Fascinating Platforms for Advanced Applications

“…Chung et al. first incorporated POSS into a nanofiltration (NF) membrane as a selective layer for the concurrent removal of Se and As ions, which are toxic to humans . The resulting NF membrane had a mean effective pore diameter of 0.65 nm, and a superior pure water permeability of 5.4 L m −2 h −1 bar −1 with significantly high rejections of SeO 3 2− , SeO 4 2− , and HAsO 4 2− toward 93.9%, 96.5%, and 97.4%, respectively.…”

“…Chung et al first incorporated POSS into a nanofiltration (NF) membrane as a selective layer for the concurrent removal of Se and As ions, which are toxic to humans. [119] The resulting NF membrane had a mean effective pore diameter of 0. on the membrane nanocomposite surface, probably due to the large POSS molecules on the membrane surface that prevent the interactions between ions and the membrane.…”

Poly(arylene ether ketone)s with low dielectric constants derived from polyhedral oligomeric silsesquioxane and difluorinated aromatic ketones

“…Among these studies, the introduction of polyhedral oligomeric silsesquioxane (POSS) into polymers has been considered one of the most effective routes . POSS, as a kind of typical silsesquioxane, has been widely introduced into polymer matrixes to form organic−inorganic hybrid materials because of their special nanostructure . In most reported cases, the POSS‐based materials all exhibited lower dielectric constants than the host polymers, and the dielectric constants can be tuned by adjusting the content of POSS .…”

“…Because of the exactly two reactive groups of DDSQ, it is often used to make linear POSS‐containing materials. In this paper, a diphenol DDSQ was used to make linear POSS‐containing materials because of the exactly two reactive groups …”