Reduced graphene oxide–metal nanoparticle composite membranes for environmental separation and chloro-organic remediation

Aher, Ashish; Thompson, Samuel J.; Nickerson, Trisha; Ormsbee, Lindell; Bhattacharyya, Dibakar

doi:10.1039/c9ra08178j

Cited by 10 publications

(2 citation statements)

References 51 publications

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“…Porous, thin membranes with asymmetric pore structure offer several features that may be advantageous for aerosol filtration . Polymer materials can be easily modified for surface functionalization to tune surface properties of the membrane or add a new functionality such as enzymes or nanoparticles. − Easy control of thickness, pore size and structure, and porosity allows for tuning the size cutoff for a given application, i.e., filtration of viruses with defined size, by controlling transport properties to minimize the pressure drop while maintaining high efficiency filtration. The wide range of tunable features may provide significant advantages.…”

Section: Introductionmentioning

confidence: 99%

Demonstration of Hollow Fiber Membrane-Based Enclosed Space Air Remediation for Capture of an Aerosolized Synthetic SARS-CoV-2 Mimic and Pseudovirus Particles

et al. 2022

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Reduction of airborne viral particles in enclosed spaces is critical in controlling pandemics. Three different hollow fiber membrane (HFM) modules were investigated for viral aerosol separation in enclosed spaces. Pore structures were characterized by scanning electron microscopy, and air transport properties were measured. Particle removal efficiency was characterized using aerosols generated by a collision atomizer from a defined mixture of synthetic nanoparticles including SARS-CoV-2 mimics (protein-coated 100 nm polystyrene). HFM1 (polyvinylidene fluoride, ∼50–1300 nm pores) demonstrated 96.5–100% efficiency for aerosols in the size range of 0.3–3 μm at a flow rate of 18.6 ± 0.3 SLPM (∼1650 LMH), whereas HFM2 (polypropylene, ∼40 nm pores) and HFM3 (hydrophilized polyether sulfone, ∼140–750 nm pores) demonstrated 99.65–100% and 98.8–100% efficiency at flow rates of 19.7 ± 0.3 SLPM (∼820 LMH) and 19.4 ± 0.2 SLPM (∼4455 LMH), respectively. Additionally, lasting filtration with minimal fouling was demonstrated using ambient aerosols over 2 days. Finally, each module was evaluated with pseudovirus (vesicular stomatitis virus) aerosol, demonstrating 99.3% (HFM1), >99.8% (HFM2), and >99.8% (HFM3) reduction in active pseudovirus titer as a direct measure of viral particle removal. These results quantified the aerosol separation efficiency of HFMs and highlight the need for further development of this technology to aid the fight against airborne viruses and particulate matter concerning human health.

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Section: Introductionmentioning

confidence: 99%

Demonstration of Hollow Fiber Membrane-Based Enclosed Space Air Remediation for Capture of an Aerosolized Synthetic SARS-CoV-2 Mimic and Pseudovirus Particles

et al. 2022

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“…Removal of mercury and other heavy metals can be associated with several of these parameters. Among the treatment processes to remove dissolved Hg from wastewater, membrane-based separation is not well explored despite offering high treatment capacities, relatively small footprints, and long-term stability suitable for full-scale operation for industrial applications. , PVDF microfiltration membranes are well studied for various separation technologies because of their high surface area and robust nature, and their surfaces are very suitable to functionalize with carboxyl (−COOH) groups. − Carboxyl groups incorporated in PVDF membranes can be activated through ethyl(dimethylaminopropyl) carbodiimide/ N -hydroxysuccinimide (EDC/NHS) coupling. ,− The NHS–O – functional groups formed during this process can subsequently be substituted by thiol-containing amines (organic compounds containing a basic nitrogen atom with a lone pair of electrons, e.g., R-NH 2 ). The resulting thiol membranes are expected to effectively absorb ionic mercury from water because of the strong propensity of thiols to bond with ionic mercury to form mercury–sulfur complexes. ,, …”

Section: Introductionmentioning

confidence: 99%

Mercury Removal from Wastewater Using Cysteamine Functionalized Membranes

et al. 2020

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This study demonstrates a three-step process consisting of primary pre-filtration followed by ultrafiltration (UF) and adsorption with thiol-functionalized microfiltration membranes (thiol membranes) to effectively remove mercury sulfide nanoparticles (HgS NPs) and dissolved mercury (Hg 2+ ) from wastewater. Thiol membranes were synthesized by incorporating either cysteine (Cys) or cysteamine (CysM) precursors onto polyacrylic acid (PAA)-functionalized polyvinylidene fluoride membranes. Carbodiimide chemistry was used to cross-link thiol (−SH) groups on membranes for metal adsorption. The thiol membranes and intermediates of the synthesis were tested for permeability and long-term mercury removal using synthetic waters and industrial wastewater spiked with HgS NPs and a Hg 2+ salt. Results show that treatment of the spiked wastewater with a UF membrane removed HgS NPs to below the method detection level (<2 ppb) for up to 12.5 h of operation. Flux reductions that occurred during the experiment were reversible by washing with water, suggesting negligible permanent fouling. Dissolved Hg 2+ species were removed to non-detection levels by passing the UF-treated wastewater through a CysM thiol membrane. The adsorption efficiency in this long-term study (>20 h) was approximately 97%. Addition of Ca 2+ cations reduced the adsorption efficiencies to 82% for the CysM membrane and to 40% for the Cys membrane. The inferior performance of Cys membranes may be explained by the presence of a carboxyl (−COOH) functional group in Cys, which may interfere in the adsorption process in the presence of multiple cations because of multication absorption. CysM membranes may therefore be more effective for treatment of wastewater than Cys membranes. Focused ion beam characterization of a CysM membrane cross section demonstrates that the adsorption of heavy metals is not limited to the membrane surface but takes place across the entire pore length. Experimental results for adsorptions of selected heavy metals on thiol membranes over a wide range of operating conditions could be predicted with modeling. These results show promising potential industrial applications of thiol-functionalized membranes.

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Functionalized Nanoparticles for Environmental Remediation

Jurado‐Sánchez

2022

Nanotechnology for Environmental Remediation

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Reduced graphene oxide–metal nanoparticle composite membranes for environmental separation and chloro-organic remediation

Abstract: This study explores the integration of separation performance was achieved in a loose nanofiltration regime with heterogeneous oxidation reactions for remediation of organic contaminants from water.

Cited by 10 publications

References 51 publications

Demonstration of Hollow Fiber Membrane-Based Enclosed Space Air Remediation for Capture of an Aerosolized Synthetic SARS-CoV-2 Mimic and Pseudovirus Particles

Demonstration of Hollow Fiber Membrane-Based Enclosed Space Air Remediation for Capture of an Aerosolized Synthetic SARS-CoV-2 Mimic and Pseudovirus Particles

Mercury Removal from Wastewater Using Cysteamine Functionalized Membranes

Functionalized Nanoparticles for Environmental Remediation

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