Defluoridation by Bare Nanoadsorbents, Nanocomposites, and Nanoadsorbent Loaded Mixed Matrix Membranes

Chaudhary, Mohit; Rawat, Shweta; Maiti, Abhijit

doi:10.1080/15422119.2022.2045610

Cited by 16 publications

(13 citation statements)

References 127 publications

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“…After that, the permeate uranium concentration increases due to the blockage of active sites. The electrostatic repulsion plays an important role in the uranium removal after 300 min as only the size exclusion principle does not hold well for the separation. − , …”

Section: Resultsmentioning

confidence: 99%

“…The electrostatic repulsion plays an important role in the uranium removal after 300 min as only the size exclusion principle does not hold well for the separation. [26][27][28][29]42 Further, to compare the performance of MMM-2 at a relatively lower feed concentration, the 2.5 ppm initial uranium concentration was chosen, keeping all other experimental conditions identical. The membrane provides safe drinking water for only 6 h within the permissible limit (Figure 4c).…”

Section: Membrane Filtration Of Uranium From Aqueous Solution As Well...mentioning

confidence: 99%

“…Adsorption, membrane filtration, precipitation, biological adsorption/biological reduction, and ion exchange are some of the methods that have been reported so far for removing uranium from the aqueous solution. ,,− Among these, batch mode adsorption and membrane filtration methods are noteworthy owing to their selectivity, reusability, high removal efficiency, and economic feasibility. − The feasibility of these techniques majorly depends upon the properties of the adsorbent and the interaction of the uranium ion with the adsorbent. − The batch mode adsorption is a widely used method in the laboratory scale and gives a very good understanding of the adsorption mechanism as well as the adsorbate–adsorbent interaction. However, due to the difficulties in the recovery of the used adsorbent, there remains challenges to adopt this as an industrial method.…”

Section: Introductionmentioning

confidence: 99%

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Removal of Uranium from Aqueous Solution and Simulated Seawater Using a Mixed Matrix Membrane Fabricated by Cyclophosphazene and Triazine-Based Inorganic–Organic Hybrid Material

Das

Rawat

Singh

et al. 2023

ACS Appl. Eng. Mater.

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The efficient removal of uranium ions from aqueous and simulated seawater is reported by using a mixed matrix membrane (MMM-2) fabricated by cyclophosphazene and triazine-based inorganic−organic hybrid material (CTHM-2) as the adsorbent. CTHM-2 with a specific surface area of 76 m 2 g −1 was synthesized within 60 min by microwave-assisted polycondensation reaction. In batch mode adsorption, the concentration of uranium has been decreased from 5 ppm to <15 ppb (permissible limit of uranium by the World Health Organization) within 120 min at pH of 6 and 298 K. However, a maximum adsorption capacity of 580 mg g −1 is estimated with 500 ppm of the initial concentration. The isotherm and kinetic studies indicate that it could fit well with the Freundlich isotherm and pseudo-second order kinetics. The negative ΔG and ΔH values indicate the spontaneous and exothermic adsorption processes, respectively. When the MMM-2 was used to treat 5 L of 5 ppm U(VI) solution, with a water flux of 8.1 L m −2 h −1 and 2 bar transmembrane pressure, it provides safe drinkable water (<15 ppb) for 300 min. Additionally, the CTHM-2 and MMM-2 could be further used to remove uranium ions from the simulated seawater with adsorption capacities of 53 and 167 mg g −1 , respectively.

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Section: Resultsmentioning

confidence: 99%

Section: Membrane Filtration Of Uranium From Aqueous Solution As Well...mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Removal of Uranium from Aqueous Solution and Simulated Seawater Using a Mixed Matrix Membrane Fabricated by Cyclophosphazene and Triazine-Based Inorganic–Organic Hybrid Material

Das

Rawat

Singh

et al. 2023

ACS Appl. Eng. Mater.

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“…Fabrication of the mixed matrix membrane (designated as N-MMM) was carried out using the phase inversion approach to remove Pb 2+ from aqueous solution utilizing NENP as the active adsorbent. ,, Typically, 3 wt % (0.127 g) of NENP was dispersed in 25 mL of NMP added and stirred for 30 min for homogeneous dispersion. PES (17 wt % (4.25 g)) was added to this dispersion and stirred for 5 h at 323 K to completely dissolve the PES.…”

Section: Experimental Detailsmentioning

confidence: 99%

“…These improve the separation efficiency and can be utilized for a wide spectrum of contaminants . Further, the high efficiency, accuracy, regeneration, and selectivity of this method make it a suitable method for wastewater treatment for industrial applications. − …”

Section: Introductionmentioning

confidence: 99%

Fabrication of a Mixed Matrix Membrane Using Nitrogen-Enriched Nanoporous Polytriazine for Removal of Pb²⁺ from Aqueous Solution

Das,

Rawat,

Chaudhary

et al. 2024

ACS Appl. Nano Mater.

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An important concern for the environment is the toxicity of lead ions in aqueous solutions. In the present research, a nitrogen-enriched nanoporous polytriazine (NENP) is synthesized (SABET ∼ 700 m2 g–1), which works well as an adsorbent to remove Pb2+ from water bodies. In batch adsorption mode, 5 mg of NENP having a high nitrogen content (∼52%) is capable of reducing the concentration of Pb2+ from 1.6 ppm to <10 ppb within 10 min, at 298 K and a pH of 7. The maximum adsorption capacity of 537 mg g–1 is estimated in 10 min for 600 ppm of Pb2+ solution having a pH of 7. Meanwhile, a mixed matrix membrane designated as N-MMM was fabricated using NENP as the active adsorbent and characterized by field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), and N2 sorption analysis. In a cross-flow membrane setup, N-MMM with the flux of 16.2 L m–2 h–1 can treat 5 L of an aqueous solution containing 1.6 ppm of Pb2+ and provide safe drinking water (<10 ppb by WHO) for 300 min within the permissible limit (WHO) at 2 bar transmembrane pressure and a cross-flow velocity of 1L/M. N-MMM exhibits a remarkably high removal efficiency of 99.4% and good retention ability up to 3 consecutive cycles. These findings will be beneficial for the cost-effective production of metal-free heteroatom-enriched nanoporous materials for efficient removal of Pb2+ ions from water bodies.

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Thermo‐responsive polymer to clean fouled forward osmosis membrane after wastewater treatment: Excellent flux recovery

Rai,

Pandey,

Singh

et al. 2024

Polymer Engineering & Sci

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Thermally responsive polymers (TRPs) have gained significant attention in the past decade due to their unique phase transition behavior, those exhibiting changes in properties with temperature variations. In water, hydrophilic block copolymers form helical structures that can transform into hydrophobic globules above the lower critical solution temperature (LCST). Fouling is one of the limiting issues for the forward osmosis (FO) process in wastewater treatment. In this work, after the treatment of wastewater from the paper and pulp industries, foulants were removed from the surface of the commercial polyamide thin‐film composite membrane of the FO process using polyvinyl methyl ether (PVME), a TRP with an LCST of 35–37°C. PVME was mixed with different aqueous solutions to form cleaning solutions. Foulant cleaning experiments utilized a 1% PVME (w/v) solution in 300 mL of de‐ionized (DI) water, while 1 M NaCl solution served as the draw solution (DS) in the FO process. Comparing the water flux (J) and change in membrane hydraulic resistance (Rf) among pristine, fouled, and cleaned membranes revealed a 56.67% increase in water flux and a 51.68% decrease in membrane resistance after PVME mixed with DI water cleaning solution showcasing its effectiveness in improving membrane performance and reducing fouling. The cleaning efficiency of two solutions, that is, 1% PVME mixed in DI water and 1% PVME mixed in 1 M aqueous urea solution, is compared. Results showed that the former cleaning solution helped to obtain 32.62% higher water flux and 56.05% less membrane resistance. Various membrane characterizations are performed, such as field emission scanning electron microscopy (FE‐SEM), which characterizes the membrane's pore structure and surface morphology, while a contact angle analyzer assesses hydrophilicity. This research highlights the use of TRPs as effective cleaning agents, enhancing membrane performance by effectively removing foulants on the membrane surface. Investigating alternative cleaning solutions also provides insights for optimizing water treatment processes.Highlights Cleaning of fouled thin‐film composite membrane using thermal‐responsive polymers (TRPs). Polyvinyl methyl ether, a TRP with an lower critical solution temperature of 35–37°C used as a cleaning agent. 60% increase in water flux was observed after the single‐step cleaning process. Multiple uses of TRP for cleaning performed with no membrane damage.

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Defluoridation by Bare Nanoadsorbents, Nanocomposites, and Nanoadsorbent Loaded Mixed Matrix Membranes

Cited by 16 publications

References 127 publications

Removal of Uranium from Aqueous Solution and Simulated Seawater Using a Mixed Matrix Membrane Fabricated by Cyclophosphazene and Triazine-Based Inorganic–Organic Hybrid Material

Removal of Uranium from Aqueous Solution and Simulated Seawater Using a Mixed Matrix Membrane Fabricated by Cyclophosphazene and Triazine-Based Inorganic–Organic Hybrid Material

Fabrication of a Mixed Matrix Membrane Using Nitrogen-Enriched Nanoporous Polytriazine for Removal of Pb²⁺ from Aqueous Solution

Thermo‐responsive polymer to clean fouled forward osmosis membrane after wastewater treatment: Excellent flux recovery

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Defluoridation by Bare Nanoadsorbents, Nanocomposites, and Nanoadsorbent Loaded Mixed Matrix Membranes

Cited by 16 publications

References 127 publications

Removal of Uranium from Aqueous Solution and Simulated Seawater Using a Mixed Matrix Membrane Fabricated by Cyclophosphazene and Triazine-Based Inorganic–Organic Hybrid Material

Removal of Uranium from Aqueous Solution and Simulated Seawater Using a Mixed Matrix Membrane Fabricated by Cyclophosphazene and Triazine-Based Inorganic–Organic Hybrid Material

Fabrication of a Mixed Matrix Membrane Using Nitrogen-Enriched Nanoporous Polytriazine for Removal of Pb2+ from Aqueous Solution

Thermo‐responsive polymer to clean fouled forward osmosis membrane after wastewater treatment: Excellent flux recovery

Contact Info

Product

Resources

About

Fabrication of a Mixed Matrix Membrane Using Nitrogen-Enriched Nanoporous Polytriazine for Removal of Pb²⁺ from Aqueous Solution