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Rasheed T. Covalent organic frameworks as promising adsorbent paradigm for environmental pollutants from aqueous matrices: Perspective and challenges. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 833:155279. [PMID: 35429563 DOI: 10.1016/j.scitotenv.2022.155279] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 03/22/2022] [Accepted: 04/10/2022] [Indexed: 06/14/2023]
Abstract
Covalent organic frameworks (COFs) are an emerging class of new porous crystalline polymers materials having robust framework, outstanding structural regularity, highly ordered aperture size, inherent porosity, and chemical stability with designer properties, making them an ideal material for adsorbing a variety of contaminants from water bodies. Presented study focusses on the current advances and progress of pristine COFs as well as COFs based composites as an emerging substitute for the adsorption and removal of a variety of pollutants including water desalination technique, heavy metals, pharmaceuticals, dyes and organic pollutants. The absorption capabilities of COFs-derived architecture are evaluated and equated with those of other commonly used adsorbents. The interaction between sorption ability and structural property as well as some regularly utilized ways to improve the adsorption performance of COFs-based materials are also reviewed. Finally, perspective and a summary about the challenges and opportunities of COFs and COFs-derived materials are discussed to deliver some exciting data for fabricating and designing of COFs and COFs-derived materials for remediation of environmental pollutants.
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Affiliation(s)
- Tahir Rasheed
- Interdisciplinary Research Center for Advanced Materials, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia.
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2
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Asghar F, Shakoor B, Fatima S, Munir S, Razzaq H, Naheed S, Butler IS. Fabrication and prospective applications of graphene oxide-modified nanocomposites for wastewater remediation. RSC Adv 2022; 12:11750-11768. [PMID: 35481102 PMCID: PMC9016740 DOI: 10.1039/d2ra00271j] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 04/04/2022] [Indexed: 11/21/2022] Open
Abstract
Water bodies have become polluted with heavy metals and hazardous contaminants as a result of fast development. Many strategies have been devised by researchers in order to remove hazardous contaminants from the aquatic environment. Utilizing graphene oxide-based composite materials as efficient adsorbents for waste water treatment, desalination, separation, and purification is gaining attraction nowadays. Some of their defining properties are high mechanical strength, hydrophilicity, remarkable flexibility, ease of synthesis, atomic thickness, and compatibility with other materials. In water treatment, high separation performance and stable graphene-based laminar structures have been the main goals. Magnetic separation is among the methods which received a lot of attention from researchers since it has been shown to be quite effective at removing harmful pollutants from aqueous solution. Graphene oxide-modified nanocomposites have provided optimal performance in water purification. This review article focusses on the fabrication of GO, rGO and MGO nanocomposites as well as the primary characterization tools needed to assess the physiochemical and structural properties of graphene-based nanocomposites. It also discusses the approaches for exploiting graphene oxide (GO), reduced graphene (rGO), and magnetic graphene oxide (MGO) to eliminate contaminants for long-term purification of water. The potential research hurdles for using fabricated MGOs as an adsorbent to remediate water contaminants like hazardous metals, radioactive metal ions, pigments, dyes, and agricultural pollutants are also highlighted. Synthesis and chacterization of graphene-based materials (GO, rGO, and MGO) by FT-IR, XRD, UV-VIS, SEM, and Raman spectroscopy, and their potential applications for wastewater treatment.![]()
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Affiliation(s)
- Faiza Asghar
- Department of Chemistry, University of Wah Quaid Avenue Wah 47040 Pakistan
| | - Bushra Shakoor
- Department of Chemistry, University of Wah Quaid Avenue Wah 47040 Pakistan
| | - Saira Fatima
- Department of Chemistry, Quaid-i-Azam University Islamabad Pakistan
| | - Shamsa Munir
- School of Applied Sciences and Humanities, National University of Technology, (NUTECH) Islamabad 44000 Pakistan
| | - Humaira Razzaq
- Department of Chemistry, University of Wah Quaid Avenue Wah 47040 Pakistan
| | - Shazia Naheed
- Department of Chemistry, University of Wah Quaid Avenue Wah 47040 Pakistan
| | - Ian S Butler
- Department of Chemistry, McGill University Montreal QC H3A 2K6 Canada
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3
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Hu L, You M, Meng J. Chlorination as a simple but effective method to improve the water/salt selectivity of polybenzimidazole for desalination membrane applications. J Memb Sci 2021. [DOI: 10.1016/j.memsci.2021.119745] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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4
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Blevins AK, Cox LM, Hu L, Drisko JA, Lin H, Bowman CN, Killgore JP, Ding Y. Spatially Controlled Permeability and Stiffness in Photopatterned Two-Stage Reactive Polymer Films for Enhanced CO2 Barrier and Mechanical Toughness. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c02355] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Adrienne K. Blevins
- Materials Science and Engineering Program, University of Colorado, Boulder, Colorado 80303, United States
| | - Lewis M. Cox
- Mechanical and Industrial Engineering Department, Montana State University, Bozeman, Montana 59715, United States
| | - Leiqing Hu
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | | | - Haiqing Lin
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Christopher N. Bowman
- Materials Science and Engineering Program, University of Colorado, Boulder, Colorado 80303, United States
| | | | - Yifu Ding
- Materials Science and Engineering Program, University of Colorado, Boulder, Colorado 80303, United States
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5
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Aghajani M, Greenberg AR, Ding Y. Thin film composite membranes: Does the porous support truly have negligible resistance? J Memb Sci 2020. [DOI: 10.1016/j.memsci.2020.118207] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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6
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Hailemariam RH, Woo YC, Damtie MM, Kim BC, Park KD, Choi JS. Reverse osmosis membrane fabrication and modification technologies and future trends: A review. Adv Colloid Interface Sci 2020; 276:102100. [PMID: 31935555 DOI: 10.1016/j.cis.2019.102100] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 12/27/2019] [Accepted: 12/27/2019] [Indexed: 12/29/2022]
Abstract
Reverse osmosis (RO) is the most widely used technology in water treatment and desalination technologies for potable water production. Since its invention, RO has undergone significant developments in terms of material science, process, system optimization, methods of membrane synthesis, and modifications. Among various materials used for the synthesis of an RO membrane, the polyamide thin-film composite (PA-TFC) is by far the most common, owing to its excellent water permeability high salt rejection, and stability. However, a tradeoff between membrane permeability and salt rejection and membrane fouling has been a major hindrance for the effective application of this membrane. Thus, a broad investigation has been carried out to address these problems, and among which co-solvent interfacial polymerization (CAIP) and the surface modification of substrates and active layers of RO membrane have been the most effective approaches for controlling and improving the surface properties of the PA-TFC membrane. In this review paper, the problems associated with the RO membrane processes and strategies has been discussed and addressed in detail. Furthermore, as the focus of this review, the major advancements in the strategies used for enhancement of RO membrane performance through CAIP, and surface modifications were scrutinized and summarized.
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Affiliation(s)
- Ruth Habte Hailemariam
- Department of Civil and Environment Engineering, University of Science and Technology, (UST), 217, Gajeong-Ro, Yuseong-Gu, Daejeon 34113, Republic of Korea
| | - Yun Chul Woo
- Department of Land, Water and Environment Research, Korea Institute of Civil Engineering and Building Technology, 283 Goyang-Daero, Ilsanseo-Gu, Goyang-Si, Gyeonggi-Do, 10223, Republic of Korea.
| | - Mekdimu Mezemir Damtie
- Department of Civil and Environment Engineering, University of Science and Technology, (UST), 217, Gajeong-Ro, Yuseong-Gu, Daejeon 34113, Republic of Korea
| | - Bong Chul Kim
- Water Environment Center, Environmental Technology Division, Korea Testing Laboratory (KTL), 87, Digital-Ro 26-Gil, Guro-Gu, Seoul 08389, Republic of Korea
| | - Kwang-Duck Park
- Department of Land, Water and Environment Research, Korea Institute of Civil Engineering and Building Technology, 283 Goyang-Daero, Ilsanseo-Gu, Goyang-Si, Gyeonggi-Do, 10223, Republic of Korea
| | - June-Seok Choi
- Department of Civil and Environment Engineering, University of Science and Technology, (UST), 217, Gajeong-Ro, Yuseong-Gu, Daejeon 34113, Republic of Korea; Department of Land, Water and Environment Research, Korea Institute of Civil Engineering and Building Technology, 283 Goyang-Daero, Ilsanseo-Gu, Goyang-Si, Gyeonggi-Do, 10223, Republic of Korea.
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7
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Xu L, Shan B, Gao C, Xu J. Multifunctional thin-film nanocomposite membranes comprising covalent organic nanosheets with high crystallinity for efficient reverse osmosis desalination. J Memb Sci 2020. [DOI: 10.1016/j.memsci.2019.117398] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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8
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Esfandian F, Peyravi M, Ghoreyshi AA, Jahanshahi M, Rad AS. Fabrication of TFC nanofiltration membranes via co-solvent assisted interfacial polymerization for lactose recovery. ARAB J CHEM 2019. [DOI: 10.1016/j.arabjc.2017.01.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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9
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Suppression of crystallization in thin films of cellulose diacetate and its effect on CO2/CH4 separation properties. J Memb Sci 2019. [DOI: 10.1016/j.memsci.2019.05.039] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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10
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Han R, Xie Y, Ma X. Crosslinked P84 copolyimide/MXene mixed matrix membrane with excellent solvent resistance and permselectivity. Chin J Chem Eng 2019. [DOI: 10.1016/j.cjche.2018.10.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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11
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Zhao Y, Dai L, Zhang Q, Zhou S, Zhang S. Chlorine-resistant sulfochlorinated and sulfonated polysulfone for reverse osmosis membranes by coating method. J Colloid Interface Sci 2019; 541:434-443. [DOI: 10.1016/j.jcis.2019.01.104] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 01/22/2019] [Accepted: 01/24/2019] [Indexed: 11/30/2022]
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12
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Wang M, Stafford CM, Cox LM, Blevins AK, Aghajani M, Killgore JP, Ding Y. Controlled Growth of Polyamide Films atop Homogenous and Heterogeneous Hydrogels using Gel-Liquid Interfacial Polymerization. MACROMOL CHEM PHYS 2019; 220:10.1002/macp.201900100. [PMID: 31579363 PMCID: PMC6774368 DOI: 10.1002/macp.201900100] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Indexed: 11/09/2022]
Abstract
Controlled growth of crosslinked polyamide (PA) thin films is demonstrated at the interface of a monomer-soaked hydrogel and an organic solution of the complementary monomer. Termed gel-liquid interfacial polymerization (GLIP), the resulting PA films are measured to be chemically and mechanically analogous to the active layer in thin film composite membranes. PA thin films are prepared using the GLIP process on both a morphologically homogeneous hydrogel prepared from poly(2-hydroxyethylmethacrylate) (PHEMA) and a phase-separated, heterogeneous hydrogel prepared from poly(acrylamide) (PAAm). Two monomer systems are examined: trimesoyl chloride (TMC) reacting with m-phenylene diamine (MPD) and TMC reacting with piperazine (PIP). Unlike the self-limiting growth behavior in TFC membrane fabrication, diffusion-limited, continuous growth of the PA films is observed, where both the thickness and roughness of the PA layers increase with reaction time. A key morphological difference is found between the two monomer systems using the GLIP process: TMC/MPD produces a ridge-and-valley surface morphology whereas TMC/PIP produces nodule/granular structures. The GLIP process represents a unique opportunity to not only explore the pore characteristics (size, spacing, and continuity) on the resulting structure and morphology of interfacially polymerized thin films, but also a method to modify the surface of (or encapsulate) hydrogels.
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Affiliation(s)
- Mengyuan Wang
- Materials Science and Engineering Program, University of Colorado, Boulder, CO, 80303, USA
- Department of Mechanical Engineering, University of Colorado, Boulder, CO, 80309-0427, USA
| | - Christopher M Stafford
- Materials Science and Engineering Division, National Institute of Standards and Technology (NIST), Gaithersburg, MD, 20899, USA
| | - Lewis M Cox
- Mechanical & Industrial Engineering Department, Montana State University, Bozeman, MT,59717-3800, USA
| | - Adrienne K Blevins
- Materials Science and Engineering Program, University of Colorado, Boulder, CO, 80303, USA
- Department of Mechanical Engineering, University of Colorado, Boulder, CO, 80309-0427, USA
| | - Masoud Aghajani
- Department of Mechanical Engineering, University of Colorado, Boulder, CO, 80309-0427, USA
| | - Jason P Killgore
- Applied Chemicals and Materials Division, National Institute of Standards and Technology (NIST), Boulder, CO 80305, USA
| | - Yifu Ding
- Materials Science and Engineering Program, University of Colorado, Boulder, CO, 80303, USA
- Department of Mechanical Engineering, University of Colorado, Boulder, CO, 80309-0427, USA
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13
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Heinz O, Aghajani M, Greenberg AR, Ding Y. Surface-patterning of polymeric membranes: fabrication and performance. Curr Opin Chem Eng 2018. [DOI: 10.1016/j.coche.2018.01.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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14
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Gohil JM, Suresh AK. Chlorine attack on reverse osmosis membranes: Mechanisms and mitigation strategies. J Memb Sci 2017. [DOI: 10.1016/j.memsci.2017.06.092] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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15
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Zhang H, Bin Li, Pan J, Qi Y, Shen J, Gao C, Van der Bruggen B. Carboxyl-functionalized graphene oxide polyamide nanofiltration membrane for desalination of dye solutions containing monovalent salt. J Memb Sci 2017. [DOI: 10.1016/j.memsci.2017.05.075] [Citation(s) in RCA: 124] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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16
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Raval HD, Gondaliya MD. A novel high-flux thin film composite reverse osmosis membrane modified by polysaccharide supramolecular assembly. J Appl Polym Sci 2017. [DOI: 10.1002/app.45026] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Hiren D. Raval
- Reverse Osmosis Division; CSIR-Central Salt and Marine Chemicals Research Institute Gijubhai Badheka Marg; Bhavnagar Gujarat 364002 India
| | - MayurKumar D. Gondaliya
- Reverse Osmosis Division; CSIR-Central Salt and Marine Chemicals Research Institute Gijubhai Badheka Marg; Bhavnagar Gujarat 364002 India
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17
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Yavari M, Maruf S, Ding Y, Lin H. Physical aging of glassy perfluoropolymers in thin film composite membranes. Part II. Glass transition temperature and the free volume model. J Memb Sci 2017. [DOI: 10.1016/j.memsci.2016.08.033] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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18
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Ding Y, Maruf S, Aghajani M, Greenberg AR. Surface patterning of polymeric membranes and its effect on antifouling characteristics. SEP SCI TECHNOL 2016. [DOI: 10.1080/01496395.2016.1201115] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Yifu Ding
- Membrane Science, Engineering and Technology Center, Department of Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado, USA
- Materials Science and Engineering Program, University of Colorado, Boulder, Colorado, USA
| | - Sajjad Maruf
- Membrane Science, Engineering and Technology Center, Department of Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado, USA
| | - Masoud Aghajani
- Membrane Science, Engineering and Technology Center, Department of Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado, USA
| | - Alan R. Greenberg
- Membrane Science, Engineering and Technology Center, Department of Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado, USA
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19
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Maruf SH, Greenberg AR, Ding Y. Influence of substrate processing and interfacial polymerization conditions on the surface topography and permselective properties of surface-patterned thin-film composite membranes. J Memb Sci 2016. [DOI: 10.1016/j.memsci.2016.04.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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20
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Hegab HM, Zou L. Graphene oxide-assisted membranes: Fabrication and potential applications in desalination and water purification. J Memb Sci 2015. [DOI: 10.1016/j.memsci.2015.03.011] [Citation(s) in RCA: 345] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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21
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Raval HD, Rana PS, Maiti S. A novel high-flux, thin-film composite reverse osmosis membrane modified by chitosan for advanced water treatment. RSC Adv 2015. [DOI: 10.1039/c4ra12610f] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
This work demonstrates a novel method for improving the performance of thin-film composite RO membrane by making a polyamide–chitosan composite.
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Affiliation(s)
- Hiren D. Raval
- Reverse Osmosis Discipline
- CSIR-Central Salt and Marine Chemicals Research Institute (CSIR-CSMCRI)
- Council of Scientific & Industrial Research (CSIR)
- Bhavnagar-364 002
- India
| | - Pranav S. Rana
- Reverse Osmosis Discipline
- CSIR-Central Salt and Marine Chemicals Research Institute (CSIR-CSMCRI)
- Council of Scientific & Industrial Research (CSIR)
- Bhavnagar-364 002
- India
| | - Subarna Maiti
- Reverse Osmosis Discipline
- CSIR-Central Salt and Marine Chemicals Research Institute (CSIR-CSMCRI)
- Council of Scientific & Industrial Research (CSIR)
- Bhavnagar-364 002
- India
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22
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Lu X, Shah P, Maruf S, Ortiz S, Hoffard T, Pellegrino J. Forensic analysis of degraded polypropylene hollow fibers utilized in microfiltration. J Appl Polym Sci 2014. [DOI: 10.1002/app.41553] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Xiaoyun Lu
- Mechanical Engineering; University of Colorado; Boulder Colorado 80309
| | - Parag Shah
- Chemical and Biological Engineering; University of Colorado; Boulder Colorado 80309
| | - Sajjad Maruf
- Mechanical Engineering; University of Colorado; Boulder Colorado 80309
| | - Sean Ortiz
- Mechanical Engineering; University of Colorado; Boulder Colorado 80309
| | - Theresa Hoffard
- Naval Facilities Engineering and Expeditionary Warfare Center; Port Hueneme California 93043
| | - John Pellegrino
- Mechanical Engineering; University of Colorado; Boulder Colorado 80309
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23
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Lee JH, Chung JY, Chan EP, Stafford CM. Correlating chlorine-induced changes in mechanical properties to performance in polyamide-based thin film composite membranes. J Memb Sci 2013. [DOI: 10.1016/j.memsci.2013.01.026] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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24
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Gu JE, Jun BM, Kwon YN. Effect of chlorination condition and permeability of chlorine species on the chlorination of a polyamide membrane. WATER RESEARCH 2012; 46:5389-5400. [PMID: 22877880 DOI: 10.1016/j.watres.2012.07.030] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 07/13/2012] [Accepted: 07/17/2012] [Indexed: 05/28/2023]
Abstract
Most studies on membrane chlorination have been investigated in an unpressurized chlorination mode, even if the polyamide membrane was continuously exposed to chlorine under high operating pressure in real water/wastewater treatment plants. In this study, performance changes due to polyamide membrane chlorination were investigated in both pressurized and unpressurized chlorination modes. Chlorination in an unpressurized mode showed a flux increase at high pH and a flux decline at low pH due to the compaction and swelling of the polyamide chains, respectively. On the other hand, chlorination performed in a pressurized mode decreased the water flux in both acidic and alkaline conditions, showing that compaction is overwhelming compared to swelling. The permeability of HOCl, a dominant species at low pH, through the polyamide membrane was pH independent and almost similar to the system recovery, but the permeability of OCl(-), which is dominant at high pH, was maxima at a neutral pH. The different performance behaviors of membranes chlorinated at various pH conditions in the presence or absence of applied pressure could be explained by the permeability of chlorine species and compaction/swelling of polymer chains after chlorination. The effect of membrane chlorination on the chemical property changes at the two different modes was confirmed using attenuated total reflection Fourier transform infrared analysis, and a conceptual model of performance change was proposed to explain the performance discrepancy between the two chlorination modes.
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Affiliation(s)
- Joung-Eun Gu
- School of Urban & Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea
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