1
|
Xu C, Wang Z, Hu Y, Chen Y. Thin-Film Composite Membrane Compaction: Exploring the Interplay among Support Compressive Modulus, Structural Characteristics, and Overall Transport Efficiency. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:8587-8596. [PMID: 38683942 PMCID: PMC11097391 DOI: 10.1021/acs.est.4c01639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 04/16/2024] [Accepted: 04/17/2024] [Indexed: 05/02/2024]
Abstract
Water scarcity has driven the demand for water production from unconventional sources and the reuse of industrial wastewater. Pressure-driven membranes, notably thin-film composite (TFC) membranes, stand as energy-efficient alternatives to the water scarcity challenge and various wastewater treatments. While pressure drives solvent movement, it concurrently triggers membrane compaction and flux deterioration. This necessitates a profound comprehension of the intricate interplay among compressive modulus, structural properties, and transport efficacy amid the compaction process. In this study, we present an all-encompassing compaction model for TFC membranes, applying authentic structural and mechanical variables, achieved by coupling viscoelasticity with Monte Carlo flux calculations based on the resistance-in-series model. Through validation against experimental data for multiple commercial membranes, we evaluated the influence of diverse physical parameters. We find that support polymers with a higher compressive modulus (lower compliance), supports with higher densities of "finger-like" pores, and "sponge-like" pores with optimum void fractions will be preferred to mitigate compaction. More importantly, we uncover a trade-off correlation between steady-state permeability and the modulus for identical support polymers displaying varying porosities. This model holds the potential as a valuable guide in shaping the design and optimization for further TFC applications and extending its utility to biological scaffolds and hydrogels with thin-film coatings in tissue engineering.
Collapse
Affiliation(s)
- Chunyan Xu
- School
of Resources & Environmental Engineering, Anhui University, Hefei, Anhui 230012, China
- School
of Civil & Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0100, United States
| | - Zhongzhen Wang
- School
of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0100, United States
| | - Yuhang Hu
- School
of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0100, United States
- Woodruff
School of Mechanical Engineering, Georgia
Institute of Technology, Atlanta, Georgia 30332-0100, United States
| | - Yongsheng Chen
- School
of Civil & Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0100, United States
| |
Collapse
|
2
|
Effects of Ethyl Lauroyl Arginate (LAE) on Biofilm Detachment: Shear Rate, Concentration, and Dosing Time. WATER 2022. [DOI: 10.3390/w14142158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Biofilm formation is one of the main obstacles in membrane treatment. The non-oxidizing biocide ethyl lauroyl arginate (LAE) is promising for mitigating biofilm development on membrane surfaces. However, the operating conditions of LAE and their impact on biofilm detachment are not comprehensively understood. In this study, a real-time in vitro flow cell system was utilized to observe biofilm dispersal caused by the shear rate, concentration, and treatment time of LAE. This confirmed that the biofilm was significantly reduced to 68.2% at a shear rate of 3.42 s−1 due to the increased physical lifting force. LAE exhibited two different mechanisms for bacterial inactivation and biofilm dispersal. Biofilms treated with LAE at sub-growth inhibitory concentrations for a longer time could effectively detach the biofilm formed on the surface of the glass slides, which can be attributed to the increased motility of microorganisms. However, a high concentration (i.e., bactericidal concentration) of LAE should be seriously considered because of the inactivated sessile bacteria and their residual debris remaining on the surface. This study sheds light on the effect of LAE on biofilm detachment and provides insights into biofouling mitigation during the membrane process.
Collapse
|
3
|
Cheng W, Lu X, Kaneda M, Zhang W, Bernstein R, Ma J, Elimelech M. Graphene Oxide-Functionalized Membranes: The Importance of Nanosheet Surface Exposure for Biofouling Resistance. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:517-526. [PMID: 31756099 DOI: 10.1021/acs.est.9b05335] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Surface functionalization using two-dimensional (2D) graphene oxide (GO) materials is a promising technique to enhance the biofouling resistance of membranes used in water purification and reuse. However, the role of GO exposure, which is crucial for the contact-mediated toxicity mechanism, has not been well evaluated or elucidated in previous studies. Herein, we employ bioinspired polydopamine chemistry to fabricate GO-functionalized membranes through two strategies: coating and blending. The two types of GO-functionalized membranes displayed comparable roughness, hydrophilicity, water permeability, and solute retention properties but different degrees of GO nanosheet exposure on the membrane surface. When in contact with the model bacterium, Escherichia coli, the GO-coated membrane exhibited enhanced biofouling resistance compared to that of the GO-blended membrane, as evidenced by lower viable cells in static adsorption experiments, and lower water flux decline and higher flux recovery in dynamic biofouling experiments. Moreover, the development of biofilm on the GO-coated membrane was also inhibited to a greater extent than on the GO-blended membrane. Taken together, our findings indicate the paramount importance of GO exposure on the membrane surface in conferring antibacterial activity and biofouling resistance, which should be considered in the future design of antibiofouling membranes using 2D nanomaterials.
Collapse
Affiliation(s)
- Wei Cheng
- State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520-8286, United States
| | - Xinglin Lu
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520-8286, United States
| | - Masashi Kaneda
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520-8286, United States
- Division of Environmental Engineering, Hokkaido University, N13W8, Kita-ku, Sapporo 060-8628, Japan
| | - Wei Zhang
- Department of Desalination and Water Treatment, Zuckerberg Institute for Water Research, The Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet 84990, Israel
| | - Roy Bernstein
- Department of Desalination and Water Treatment, Zuckerberg Institute for Water Research, The Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet 84990, Israel
| | - Jun Ma
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Menachem Elimelech
- Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06520-8286, United States
| |
Collapse
|
4
|
Improvement in cyst recovery and molecular detection of Giardia duodenalis from stool samples. Mol Biol Rep 2019; 47:1233-1239. [PMID: 31813130 DOI: 10.1007/s11033-019-05224-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Accepted: 12/04/2019] [Indexed: 10/25/2022]
Abstract
Molecular detection of Giardia duodenalis by polymerase chain reaction (PCR) is difficult in faecal samples due to inhibitors that contaminate DNA preparations, or due to low cyst concentrations. In order to eliminate inhibitors, improve cyst recovery and molecular detection of G. duodenalis, different types of water, distillates (MDs), deionized (MDz), injection (MI) or Milli-Q® (MM) were used instead of formaldehyde (F) in the laboratory routine method (Ritchie). Cysts were isolated from faecal samples with low cyst concentrations (< 1 cyst/field), medium (1-2 cysts/field) or high (> 2 cysts/field). Cyst recovery was improved using all water types (MDs, MDz, MI, MM) compared to formaldehyde. At all cyst concentrations, the use of MM consistently showed the greatest recovery of G. duodenalis cysts . DNA samples from recovered cysts were tested for the glutamate dehydrogenase (GDH) and β-giardin (βg) genes. The use of Milli-Q® water allowed to detect both genes in all cyst concentrations, including low. The method processed with the other types of water amplified these genes at high and medium cyst concentrations. GDH and βg genes were not detected when the sample was processed with formaldehyde. These experimental results were confirmed in clinical samples. The results suggest that Milli-Q® water provides the highest cyst recovery from stool samples and, correspondingly, the highest sensitivity for detecting G. duodenalis by microscopy or PCR for GDH and βg genes, even at low concentration of cysts.
Collapse
|
5
|
Kim LH, Vrouwenvelder JS. Insignificant Impact of Chemotactic Responses of Pseudomonas aeruginosa on the Bacterial Attachment to Organic Pre-Conditioned RO Membranes. MEMBRANES 2019; 9:membranes9120162. [PMID: 31810273 PMCID: PMC6950137 DOI: 10.3390/membranes9120162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 11/25/2019] [Accepted: 11/28/2019] [Indexed: 12/03/2022]
Abstract
We investigated the impact of conditioning compositions on the way bacteria move and adhere to reverse osmosis (RO) membranes that have been pre-conditioned by organic compounds. We used humic acid (HA), bovine serum albumin (BSA), and sodium alginate (SA) to simulate conditioning layers on the RO membranes. First, we investigated the chemotactic responses of Pseudomonas aeruginosa PAO1 to the organic substances and the impact of changes in physicochemical characteristics of pre-conditioned membranes on bacterial attachment. Second, we observed bacterial attachment under the presence or absence of nutrients or microbial metabolic activity. Results showed that there was no relationship between the chemotactic response of P. aeruginosa PAO1 and the organic substances, and the changes in hydrophobicity, surface free energy, and surface charge resulting from changing the composition of the conditioning layer did not seem to affect bacterial attachment, whereas changing the roughness of the conditioned membrane exponentially did (exponential correlation coefficient, R2 = 0.85). We found that the initial bacterial attachment on the membrane surface is influenced by (i) the nutrients in the feed solution and (ii) the microbial metabolic activity, whereas the chemotaxis response has a negligible impact. This study would help to establish a suitable strategy to manage bacterial attachment.
Collapse
Affiliation(s)
- Lan Hee Kim
- Water Desalination and Reuse Center (WDRC), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia;
| | - Johannes S. Vrouwenvelder
- Water Desalination and Reuse Center (WDRC), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia;
- Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
- Correspondence:
| |
Collapse
|
6
|
Cao H, O'Rourke M, Habimana O, Casey E. Analysis of surrogate bacterial cell transport to nanofiltration membranes: Effect of salt concentration and hydrodynamics. Sep Purif Technol 2018. [DOI: 10.1016/j.seppur.2018.06.072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
7
|
Tarifa MC, Lozano JE, Brugnoni LI. Disinfection efficacy over yeast biofilms of juice processing industries. Food Res Int 2018; 105:473-481. [DOI: 10.1016/j.foodres.2017.11.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 11/08/2017] [Accepted: 11/19/2017] [Indexed: 10/18/2022]
|
8
|
Nanofiltration-induced cell death: An integral perspective of early stage biofouling under permeate flux conditions. J Memb Sci 2017. [DOI: 10.1016/j.memsci.2017.07.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
9
|
Choudhari S, Habimana O, Hannon J, Allen A, Cummins E, Casey E. Dynamics of silver elution from functionalised antimicrobial nanofiltration membranes. BIOFOULING 2017; 33:520-529. [PMID: 28604168 DOI: 10.1080/08927014.2017.1331436] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Accepted: 05/12/2017] [Indexed: 06/07/2023]
Abstract
In an effort to mitigate biofouling on thin film composite membranes such as nanofiltration and reverse osmosis, a myriad of different surface modification strategies has been published. The use of silver nanoparticles (Ag-NPs) has emerged as being particularly promising. Nevertheless, the stability of these surface modifications is still poorly understood, particularly under permeate flux conditions. Leaching or elution of Ag-NPs from the membrane surface can not only affect the antimicrobial characteristics of the membrane, but could also potentially present an environmental liability when applied in industrial-scale systems. This study sought to investigate the dynamics of silver elution and the bactericidal effect of an Ag-NP functionalised NF270 membrane. Inductively coupled plasma-atomic emission spectroscopy was used to show that the bulk of leached silver occurred at the start of experimental runs, and was found to be independent of salt or permeate conditions used. Cumulative amounts of leached silver did, however, stabilise following the initial release, and were shown to have maintained the biocidal characteristics of the modified membrane, as observed by a higher fraction of structurally damaged Pseudomonas fluorescens cells. These results highlight the need to comprehensively assess the time-dependent nature of bactericidal membranes.
Collapse
Affiliation(s)
- S Choudhari
- a School of Chemical and Bioprocess Engineering , University College Dublin (UCD) , Dublin , Ireland
- b Department of Biological Sciences , Dayananda Sagar University , Bangalore , India
| | - O Habimana
- c School of Biological Sciences , The University of Hong Kong , Hong Kong , PR China
| | - J Hannon
- d School of Biosystems and Food Engineering, Agricultural and Food Science Centre , University College Dublin (UCD) , Dublin , Ireland
| | - A Allen
- a School of Chemical and Bioprocess Engineering , University College Dublin (UCD) , Dublin , Ireland
| | - E Cummins
- d School of Biosystems and Food Engineering, Agricultural and Food Science Centre , University College Dublin (UCD) , Dublin , Ireland
| | - E Casey
- a School of Chemical and Bioprocess Engineering , University College Dublin (UCD) , Dublin , Ireland
| |
Collapse
|
10
|
Alayande AB, Kim LH, Kim IS. Cleaning efficacy of hydroxypropyl-beta-cyclodextrin for biofouling reduction on reverse osmosis membranes. BIOFOULING 2016; 32:359-370. [PMID: 26923225 DOI: 10.1080/08927014.2016.1151008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In this study, an environmentally friendly compound, hydroxypropyl-beta-cyclodextrin (HP-β-CD) was applied to clean reverse osmosis (RO) membranes fouled by microorganisms. The cleaning with HP-β-CD removed the biofilm and resulted in a flux recovery ratio (FRR) of 102%. As cleaning efficiency is sometimes difficult to determine using flux recovery data alone, attached bacterial cells and extracellular polymeric substances (EPS) were quantified after cleaning the biofouled membrane with HP-β-CD. Membrane surface characterization using scanning electron microscopy (SEM), attenuated total reflectance Fourier transform infrared (ATR-FTIR) and atomic force microscopy (AFM) confirmed the effectiveness of HP-β-CD in removal of biofilm from the RO membrane surface. Finally, a comparative study was performed to investigate the competitiveness of HP-β-CD with other known cleaning agents such as sodium dodecyl sulfate (SDS), ethylenediaminetetraacetic acid (EDTA), Tween 20, rhamnolipid, nisin, and surfactin. In all cases, HP-β-CD was superior.
Collapse
Affiliation(s)
- Abayomi Babatunde Alayande
- a Global Desalination Research Center (GDRC), School of Environmental Science and Engineering , Gwangju Institute of Science and Technology (GIST) , Gwangju , Republic of Korea
| | - Lan Hee Kim
- a Global Desalination Research Center (GDRC), School of Environmental Science and Engineering , Gwangju Institute of Science and Technology (GIST) , Gwangju , Republic of Korea
| | - In S Kim
- a Global Desalination Research Center (GDRC), School of Environmental Science and Engineering , Gwangju Institute of Science and Technology (GIST) , Gwangju , Republic of Korea
| |
Collapse
|
11
|
Allen A, Semião AJ, Habimana O, Heffernan R, Safari A, Casey E. Nanofiltration and reverse osmosis surface topographical heterogeneities: Do they matter for initial bacterial adhesion? J Memb Sci 2015. [DOI: 10.1016/j.memsci.2015.03.029] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
12
|
Cao H, Habimana O, Semião AJ, Allen A, Heffernan R, Casey E. Understanding particle deposition kinetics on NF membranes: A focus on micro-beads and membrane interactions at different environmental conditions. J Memb Sci 2015. [DOI: 10.1016/j.memsci.2014.10.038] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
13
|
Heffernan R, Habimana O, Semião AJC, Cao H, Safari A, Casey E. A physical impact of organic fouling layers on bacterial adhesion during nanofiltration. WATER RESEARCH 2014; 67:118-28. [PMID: 25265304 DOI: 10.1016/j.watres.2014.09.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 09/05/2014] [Accepted: 09/06/2014] [Indexed: 05/16/2023]
Abstract
Organic conditioning films have been shown to alter properties of surfaces, such as hydrophobicity and surface free energy. Furthermore, initial bacterial adhesion has been shown to depend on the conditioning film surface properties as opposed to the properties of the virgin surface. For the particular case of nanofiltration membranes under permeate flux conditions, however, the conditioning film thickens to form a thin fouling layer. This study hence sought to determine if a thin fouling layer deposited on a nanofiltration membrane under permeate flux conditions governed bacterial adhesion in the same manner as a conditioning film on a surface. Thin fouling layers (less than 50 μm thick) of humic acid or alginic acid were formed on Dow Filmtec NF90 membranes and analysed using Atomic Force Microscopy (AFM), confocal microscopy and surface energy techniques. Fluorescent microscopy was then used to quantify adhesion of Pseudomonas fluorescens bacterial cells onto virgin or fouled membranes under filtration conditions. It was found that instead of adhering on or into the organic fouling layer, the bacterial cells penetrated the thin fouling layer and adhered directly to the membrane surface underneath. Contrary to what surface energy measurements of the fouling layer would indicate, bacteria adhered to a greater extent onto clean membranes (24 ± 3% surface coverage) than onto those fouled with humic acid (9.8 ± 4%) or alginic acid (7.5 ± 4%). These results were confirmed by AFM measurements which indicated that a considerable amount of energy (10(-7) J/μm) was dissipated when attempting to penetrate the fouling layers compared to adhering onto clean NF90 membranes (10(-15) J/μm). The added resistance of this fouling layer was thusly seen to reduce the number of bacterial cells which could reach the membrane surface under permeate conditions. This research has highlighted an important difference between fouling layers for the particular case of nanofiltration membranes under permeate flux conditions and surface conditioning films which should be considered when conducting adhesion experiments under filtration conditions. It has also shown AFM to be an integral tool for such experiments.
Collapse
Affiliation(s)
- R Heffernan
- School of Chemical and Bioprocess Engineering, University College Dublin, Co. Dublin, Ireland
| | - O Habimana
- School of Chemical and Bioprocess Engineering, University College Dublin, Co. Dublin, Ireland
| | - A J C Semião
- School of Engineering, The University of Edinburgh, Edinburgh, United Kingdom
| | - H Cao
- School of Chemical and Bioprocess Engineering, University College Dublin, Co. Dublin, Ireland
| | - A Safari
- School of Chemical and Bioprocess Engineering, University College Dublin, Co. Dublin, Ireland
| | - E Casey
- School of Chemical and Bioprocess Engineering, University College Dublin, Co. Dublin, Ireland.
| |
Collapse
|
14
|
Semião AJC, Habimana O, Casey E. Bacterial adhesion onto nanofiltration and reverse osmosis membranes: effect of permeate flux. WATER RESEARCH 2014; 63:296-305. [PMID: 25016321 DOI: 10.1016/j.watres.2014.06.031] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 06/20/2014] [Accepted: 06/22/2014] [Indexed: 06/03/2023]
Abstract
The influence of permeate flux on bacterial adhesion to NF and RO membranes was examined using two model Pseudomonas species, namely Pseudomonas fluorescens and Pseudomonas putida. To better understand the initial biofouling profile during NF/RO processes, deposition experiments were conducted in cross flow under permeate flux varying from 0.5 up to 120 L/(h m(2)), using six NF and RO membranes each having different surface properties. All experiments were performed at a Reynolds number of 579. Complementary adhesion experiments were performed using Pseudomonas cells grown to early-, mid- and late-exponential growth phases to evaluate the effect of bacterial cell surface properties during cell adhesion under permeate flux conditions. Results from this study show that initial bacterial adhesion is strongly dependent on the permeate flux conditions, where increased adhesion was obtained with increased permeate flux, until a maximum of 40% coverage was reached. Membrane surface properties or bacterial growth stages was further found to have little impact on bacterial adhesion to NF and RO membrane surfaces under the conditions tested. These results emphasise the importance of conducting adhesion and biofouling experiments under realistic permeate flux conditions, and raises questions about the efficacy of the methods for the evaluation of antifouling membranes in which bacterial adhesion is commonly assessed under zero-flux or low flux conditions, unrepresentative of full-scale NF/RO processes.
Collapse
Affiliation(s)
| | - Olivier Habimana
- School of Chemical and Bioprocess Engineering, University College Dublin (UCD), Ireland
| | - Eoin Casey
- School of Chemical and Bioprocess Engineering, University College Dublin (UCD), Ireland.
| |
Collapse
|
15
|
Habimana O, Semião AJC, Casey E. Upon impact: the fate of adhering Pseudomonas fluorescens cells during nanofiltration. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:9641-9650. [PMID: 25072514 DOI: 10.1021/es500585e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Nanofiltration (NF) is a high-pressure membrane filtration process increasingly applied in drinking water treatment and water reuse processes. NF typically rejects divalent salts, organic matter, and micropollutants. However, the efficiency of NF is adversely affected by membrane biofouling, during which microorganisms adhere to the membrane and proliferate to create a biofilm. Here we show that adhered Pseudomonas fluorescens cells under high permeate flux conditions are met with high fluid shear and convective fluxes at the membrane-liquid interface, resulting in their structural damage and collapse. These results were confirmed by fluorescent staining, flow cytometry, and scanning electron microscopy. This present study offers a "first-glimpse" of cell damage and death during the initial phases of bacterial adhesion to NF membranes and raises a key question about the role of this observed phenomena during early-stage biofilm formation under permeate flux and cross-flow conditions.
Collapse
Affiliation(s)
- Olivier Habimana
- School of Chemical and Bioprocess Engineering, University College Dublin (UCD) , Belfield, Dublin 4, Ireland
| | | | | |
Collapse
|
16
|
Habimana O, Semião A, Casey E. The role of cell-surface interactions in bacterial initial adhesion and consequent biofilm formation on nanofiltration/reverse osmosis membranes. J Memb Sci 2014. [DOI: 10.1016/j.memsci.2013.11.043] [Citation(s) in RCA: 138] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
17
|
Heffernan R, Semião A, Desmond P, Cao H, Safari A, Habimana O, Casey E. Disinfection of a polyamide nanofiltration membrane using ethanol. J Memb Sci 2013. [DOI: 10.1016/j.memsci.2013.07.069] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
18
|
|