Polyamide-based thin film composite (TFC) membranes are generally optimized for salt rejection but not for the removal of trace organic contaminants (TrOCs). The insufficient rejection of TrOCs such as endocrine disrupting compounds (EDCs) by polyamide membranes can jeopardize product water safety in wastewater reclamation. In this study, we report a novel nonpolyamide membrane chemistry using green tannic acid-iron (TA-Fe) complexes to remove TrOCs. The nanofiltration membrane formed at a TA-Fe molar ratio of 1:3 (TA-Fe3) had a continuous thin rejection layer of 10-30 nm in thickness, together with a water permeability of 5.1 Lmhbar and a NaSO rejection of 89.7%. Meanwhile, this membrane presented significantly higher rejection of EDCs (up to 99.7%) than that of polyamide membranes (up to 81.8%). Quartz crystal microbalance results revealed that the sorption amount of a model EDC, benzylparbaen, by TA-Fe3 layer was nearly 2 orders of magnitude less than that by polyamide, leading to reduced transmission and higher rejection. Further analysis of membrane revealed a much greater water/EDC selectivity of the TA-Fe3 membrane compared to the polyamide membranes.
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http://dx.doi.org/10.1021/acs.est.8b06422 | DOI Listing |
Nat Commun
January 2025
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, China.
Thin-film composite polyamide (TFC PA) membranes hold promise for energy-efficient liquid separation, but achieving high permeance and precise separation membrane via a facile approach that is compatible with present manufacturing line remains a great challenge. Herein, we demonstrate the use of lignin alkali (LA) derived from waste of paper pulp as an aqueous phase additive to regulate interfacial polymerization (IP) process for achieving high performance nanofiltration (NF) membrane. Various characterizations and molecular dynamics simulations revealed that LA can promote the diffusion and partition of aqueous phase monomer piperazine (PIP) molecules into organic phase and their uniform dispersion on substrate, accelerating the IP reaction and promoting greater interfacial instabilities, thus endowing formation of TFC NF membrane with an ultrathin, highly cross-linked, and crumpled PA layer.
View Article and Find Full Text PDFWater Res
December 2024
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, PR China.
Nanofiltration (NF) membranes offer tremendous potential in wastewater reuse, desalination, and resource recovery to alleviate water scarcity and environmental contamination. However, separating micropollutants and charged ions from wastewater while maintaining high water permeation remains challenging for conventional NF membranes. Customizing diffusion and interaction behavior of monomers at membrane-forming interfaces is promising for regulating interior pore structures and surface morphology properties for polyamide NF membranes, reaching efficient screening and retaining of solutes from water.
View Article and Find Full Text PDFWater Res
December 2024
Research Center for Membrane and Film Technology, Kobe University, 1-1 Rokkodaicho, Nada, Kobe 657-8501, Japan; Department of Chemical Science and Engineering, Kobe University, 1-1 Rokkodaicho, Nada, Kobe 657-8501, Japan. Electronic address:
Nanofiltration (NF) offers a scalable and energy-efficient method for lithium extraction from salt lakes. However, the selective separation of lithium from magnesium, particularly in brines with high magnesium concentrations, remains a significant challenge due to the close similarity in their hydrated ionic radii. The limited Li/Mgselectivity of current NF membranes is primarily attributed to insufficient control over pore size and surface charge.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Chemistry, University of Birjand, Birjand, 9717434765, Iran.
Herein, we discuss the structure-function of biomimetic imidazole-quartet substrates (I-quartets) obtained through the adaptive self-assembly of octyl-ureido-polyol structures in polyamide membranes designed as adsorbents. Molecular dynamics (MD) and well-tempered metadynamics simulations are utilized to examine ion contaminants' adsorption process and dynamic behaviors onto alkylureido-ethylimidazoles with well-defined supramolecular structures. Moreover, the atoms-in-molecules (AIM) analysis identified multiple types of atomic interactions between the contaminant molecules and the substrates.
View Article and Find Full Text PDFNat Commun
December 2024
School of Civil & Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
Per- and polyfluoroalkyl substances (PFASs) have recently garnered considerable concerns regarding their impacts on human and ecological health. Despite the important roles of polyamide membranes in remediating PFASs-contaminated water, the governing factors influencing PFAS transport across these membranes remain elusive. In this study, we investigate PFAS rejection by polyamide membranes using two machine learning (ML) models, namely XGBoost and multimodal transformer models.
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