1
|
AbuKhadra D, Dan Grossman A, Al-Ashhab A, Al-Sharabati I, Bernstein R, Herzberg M. The effect of temperature on fouling in anaerobic membrane bioreactor: SMP- and EPS-membrane interactions. WATER RESEARCH 2024; 260:121867. [PMID: 38878312 DOI: 10.1016/j.watres.2024.121867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 05/20/2024] [Accepted: 06/02/2024] [Indexed: 07/27/2024]
Abstract
Biofouling is the main challenge in the operation of anaerobic membrane bioreactors (AnMBRs). Biofouling strongly depends on temperature; therefore, we hypothesize that the interactions and viscoelastic properties of soluble microbial products (SMP) and extracellular polymeric substances (EPS) vary with temperature, consequently influencing membrane permeability. This study compares the performance of an AnMBR operated at a similar permeate flux at two temperatures. The transmembrane pressure (TMP) rose rapidly after 5 ± 2 days at 25 °C but only after 18 ± 2 days at 35 °C, although the reactor's biological performance was similar at both temperatures, in terms of the efficiency of dissolved organic carbon removal and biogas composition, which were obtained by changing the hydraulic retention time. Using confocal laser scanning microscopy (CLSM), a higher biofilm amount was detected at 25 °C than at 35 °C, while quartz crystal microbalance with dissipation (QCM-D) showed a more adhesive, but less viscous and elastic EPS layer. In situ optical coherence tomography (OCT) of an ultra-filtration membrane, fed with the mixed liquor suspended solids (MLSS) at the two temperatures, revealed that while a higher rate of TMP increase was obtained at 25 °C, the attachment of biomass from MLSS was markedly less. Increased EPS adhesion to the membrane can accelerate TMP increase during the operation of both the AnMBR and the OCT filtration cell. EPS's reduced viscoelasticity at 25 °C suggests reduced floc integrity and possible increased EPS penetration into the membrane pores. Analysis of the structures of the microbial communities constituting the AnMBR flocs and membrane biofilms reveals temperature's effects on microbial richness, diversity, and abundance, which likely influence the observed EPS properties and consequent AnMBR fouling.
Collapse
Affiliation(s)
- Diaa AbuKhadra
- Zuckerberg Institute for Water Research (ZIWR), The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 84990, Israel
| | - Amit Dan Grossman
- Zuckerberg Institute for Water Research (ZIWR), The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 84990, Israel
| | - Ashraf Al-Ashhab
- The Dead Sea and Arava Science Center, Masada 86190, Israel; Ben-Gurion University of the Negev, Eilat campus, Israel
| | | | - Roy Bernstein
- Zuckerberg Institute for Water Research (ZIWR), The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 84990, Israel.
| | - Moshe Herzberg
- Zuckerberg Institute for Water Research (ZIWR), The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 84990, Israel.
| |
Collapse
|
2
|
Cross-contamination of mature Listeria monocytogenes biofilms from stainless steel surfaces to chicken broth before and after the application of chlorinated alkaline and enzymatic detergents. Food Microbiol 2023; 112:104236. [PMID: 36906320 DOI: 10.1016/j.fm.2023.104236] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 02/07/2023] [Accepted: 02/07/2023] [Indexed: 02/10/2023]
Abstract
The objectives of this study were, firstly, to compare a conventional (i.e., chlorinated alkaline) versus an alternative (chlorinated alkaline plus enzymatic) treatment effectivity for the elimination of biofilms from different L. monocytogenes strains (CECT 5672, CECT 935, S2-bac and EDG-e). Secondly, to evaluate the cross-contamination to chicken broth from non-treated and treated biofilms formed on stainless steel surfaces. Results showed that all L. monocytogenes strains were able to adhere and develop biofilms at approximately the same growth levels (≈5.82 log CFU/cm2). When non-treated biofilms were put into contact with the model food, obtained an average transference rate of potential global cross-contamination of 20.4%. Biofilms treated with the chlorinated alkaline detergent obtained transference rates similar to non-treated biofilms as a high number of residual cells (i.e., around 4 to 5 Log CFU/cm2) were present on the surface, except for EDG-e strain on which transference rate diminished to 0.45%, which was related to the protective matrix. Contrarily, the alternative treatment was shown to not produce cross-contamination to the chicken broth due to its high effectivity for biofilm control (<0.50% of transference) except for CECT 935 strain that had a different behavior. Therefore, changing to more intense cleaning treatments in the processing environments can reduce risk of cross-contamination.
Collapse
|
3
|
Han F, Zhao J, Bian Y, Guo J, Chen L. Electro mitigation of calcium carbonate and calcium sulfate scaling in an optimized thermal conductive membrane distillation process. Sep Purif Technol 2023. [DOI: 10.1016/j.seppur.2023.123796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
|
4
|
Mazaheri T, Cervantes-Huamán B, Turitich L, Ripolles-Avila C, Rodríguez-Jerez J. Removal of Listeria monocytogenes biofilms on stainless steel surfaces through conventional and alternative cleaning solutions. Int J Food Microbiol 2022; 381:109888. [DOI: 10.1016/j.ijfoodmicro.2022.109888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 08/16/2022] [Accepted: 08/22/2022] [Indexed: 10/31/2022]
|
5
|
Barbhuiya NH, Misra U, Singh SP. Biocatalytic membranes for combating the challenges of membrane fouling and micropollutants in water purification: A review. CHEMOSPHERE 2022; 286:131757. [PMID: 34371356 DOI: 10.1016/j.chemosphere.2021.131757] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 07/17/2021] [Accepted: 07/30/2021] [Indexed: 06/13/2023]
Abstract
Over the last few years, the list of water contaminants has grown tremendously due to many anthropogenic activities. Various conventional technologies are available for water and wastewater treatment. However, micropollutants of emerging concern (MEC) are posing a great threat due to their activity at trace concentration and poor removal efficiency by the conventional treatment processes. Advanced technology like membrane technology can remove MEC to some extent. However, issues like the different chemical properties of MEC, selectivity, and fouling of membranes can affect the removal efficiency. Moreover, the concentrate from the membrane filtration may need further treatment. Enzymatic degradation of pollutants and foulants is one of the green approaches for removing various contaminants from the water as well as mitigating membrane fouling. Biocatalytic membranes (BCMs), in which enzymes are immobilized on membranes, combines the advantages of membrane separation and enzymatic degradation. This review article discussed various commonly used enzymes in BCMs for removing MEC and fouling. The majorly used enzymes were oxidoreductases and hydrolases for removing MEC, antifouling, and self-cleaning ability. The various BCM synthesis processes based on entrapment, crosslinking, and binding have been summarized, along with the effects of the addition of the nanoparticles on the performances of the BCMs. The scale-up, commercial viability, challenges, and future direction for improving BCMs have been discussed and shown bright possibilities for these new generation membranes.
Collapse
Affiliation(s)
- Najmul Haque Barbhuiya
- Environmental Science and Engineering Department (ESED), Indian Institute of Technology Bombay, Mumbai, 400076, India
| | - Utkarsh Misra
- Environmental Science and Engineering Department (ESED), Indian Institute of Technology Bombay, Mumbai, 400076, India; Centre for Research in Nanotechnology & Science (CRNTS), Indian Institute of Technology Bombay, Mumbai, 400076, India
| | - Swatantra P Singh
- Environmental Science and Engineering Department (ESED), Indian Institute of Technology Bombay, Mumbai, 400076, India; Centre for Research in Nanotechnology & Science (CRNTS), Indian Institute of Technology Bombay, Mumbai, 400076, India; Interdisciplinary Program in Climate Studies (IDPCS), Indian Institute of Technology Bombay, Mumbai, 400076, India.
| |
Collapse
|
6
|
Zhang L, Graham N, Derlon N, Tang Y, Siddique MS, Xu L, Yu W. Biofouling by ultra-low pressure filtration of surface water: The paramount role of initial available biopolymers. J Memb Sci 2021. [DOI: 10.1016/j.memsci.2021.119740] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
7
|
Feng M, Lee S, Chan C, Zhou R. Molecular Insight into AC Electric Field Enhanced Removal of Protein Aggregates from a Material Surface. J Phys Chem B 2021; 125:12147-12153. [PMID: 34714645 DOI: 10.1021/acs.jpcb.1c05682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Biofouling, caused by unwanted accumulation of the biological molecules on the material surface, is a common problem when medical devices are planted in the human body. Application of an electric field was first suggested in the 1960s along with many other approaches to deactivate the biofouling process. There are experiments showing a higher efficiency in reducing the biofouling using the alternating current (AC) compared to the direct current (DC). Here, using molecular dynamics (MD) simulations, we compared the binding stability of a single protein molecule on a graphene surface with either an AC or a DC field was applied. We first showed that the protein molecule, initially attached to the graphene surface, will spontaneously be desorbed by the applied AC electric field, while it remains intact under the DC field of the same voltage. We then revealed that the desorption of the protein by the AC electric field is kinetically controlled. As the orientation of the protein changed alongside the reversing electric field, the protein-graphene interface would be destabilized the most if the AC frequency was close to that of the relaxation of the protein dipole moment (i.e., resonance).
Collapse
Affiliation(s)
- Mei Feng
- Institute of Quantitative Biology, Department of Physics, and College of Life Sciences, Zhejiang University, 310027 Hangzhou, China.,Lanzhou Center for Theoretical Physics, Key Laboratory of Theoretical Physics of Gansu Province, Lanzhou University, Lanzhou, Gansu 730000, China
| | - Sangyun Lee
- Computational Biology Center, IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598, United States
| | - Chun Chan
- Institute of Quantitative Biology, Department of Physics, and College of Life Sciences, Zhejiang University, 310027 Hangzhou, China
| | - Ruhong Zhou
- Institute of Quantitative Biology, Department of Physics, and College of Life Sciences, Zhejiang University, 310027 Hangzhou, China.,Department of Chemistry, Columbia University, New York, New York 10027, United States
| |
Collapse
|
8
|
Rice D, Rajwade K, Zuo K, Bansal R, Li Q, Garcia-Segura S, Perreault F. Electrochemically-active carbon nanotube coatings for biofouling mitigation: Cleaning kinetics and energy consumption for cathodic and anodic regimes. J Colloid Interface Sci 2021; 603:391-397. [PMID: 34197987 DOI: 10.1016/j.jcis.2021.06.090] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/07/2021] [Accepted: 06/14/2021] [Indexed: 11/28/2022]
Abstract
Biofouling is a major obstacle in engineered systems exposed to aqueous conditions. Many attempts have been made to engineer the surface properties of materials to render them resistant to biofouling. These modifications typically rely on passive antimicrobial or anti-adhesive surface coatings that prevent the deposition of bacteria or inactivate them once they reach the surface. However, no surface modification strategy completely prevents biofilm formation, and, over time, surfaces will be fouled and require cleaning. In this work, we demonstrate the capacity of electrochemical carbon nanotube coatings in dispersing biofilms formed on the surface. A systematic analysis of the biofilm removal kinetics in function of applied current density is made to identify the optimal current conditions needed for efficient surface cleaning. Operating the electrochemically active surface as a cathode produces superior results compared to when it is operated as an anode. Specifically, the 5.00 A m-2 and 2.50 A m-2 cathodic conditions produced rapid cleaning, with complete biofilm dispersal after 2 min of operation. Surface cleaning is attributed to the generation of microbubbles on the surface that scours the surface to remove the adhered biofilm. Energy consumption analyses indicate that the 2.50 A m-2 cathodic condition offers the best combination of cleaning kinetics and energy consumption achieving 99% biofilm removal at an energy cost of ~$ 0.0318 m-2. This approach can be competitive compared to the current chemical cleaning strategies, while offering an opportunity for a more sustainable and integrated approach for biofouling management in engineered systems.
Collapse
Affiliation(s)
- Douglas Rice
- School of Sustainable Engineering and the Built Environment, Arizona State University, United States; Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, United States
| | - Kimya Rajwade
- School of Sustainable Engineering and the Built Environment, Arizona State University, United States; Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, United States
| | - Kuichang Zuo
- Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, United States; Department of Civil and Environmental Engineering, Rice University, United States
| | - Rishabh Bansal
- Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, United States; School for Engineering of Matter, Transport and Energy, Arizona State University, United States
| | - Qilin Li
- Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, United States; Department of Civil and Environmental Engineering, Rice University, United States
| | - Sergi Garcia-Segura
- School of Sustainable Engineering and the Built Environment, Arizona State University, United States; Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, United States
| | - François Perreault
- School of Sustainable Engineering and the Built Environment, Arizona State University, United States; Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, United States.
| |
Collapse
|
9
|
Huang J, Wu X, Liang Z, Yu Y, Liu G. Water flushing irremovable biofilms on support material in dynamic membrane bioreactor: Formation, composition, and microbial community. CHEMOSPHERE 2021; 271:129813. [PMID: 33556632 DOI: 10.1016/j.chemosphere.2021.129813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 01/19/2021] [Accepted: 01/25/2021] [Indexed: 06/12/2023]
Abstract
Dynamic membrane bioreactors mainly rely on the in-situ formed biofilms on support materials to reject fine particles in water. The development of irremovable biofilms on support materials can decrease the cleaning efficiency when removing the unwanted biofilms with low permeability by water flushing. In the present study, the initial formed biofilms on support materials at 5-day solids retention time (SRT) were removable by water flushing. After repeated cleaning with off-line water flushing during operation, however, irremovable biofilms were developed gradually inside the mesh pores and thus, rapid rising in transmembrane pressure occurred in every one to three days. At 20-day SRT, the biofilms formed on support materials with the same operation time were still removable. Therefore, both low SRT and repeated water flushing promoted the formation of irremovable biofilms on support materials. Further study found that the composition and microbial community between the irremovable and removable biofilms were significantly different, which differentiated the biofilm adhesion and removability. The irremovable biofilms had a greater faction of proteins (49.0%) and β-d-glucopyranose polysaccharides (17.8%) in extracellular polymeric substance (EPS), while the removable biofilms had a greater fraction of α-d-glucopyranose polysaccharides. After repeated cleaning with off-line water flushing during operation, Nitrospiraceae was selectively enriched in the irremovable biofilms at a relative abundance of 39.1%, which could have resulted in the particular EPS matrix that strengthened the biofilm adhesion.
Collapse
Affiliation(s)
- Ju Huang
- School of Environment, Guangdong Engineering Research Center of Water Treatment Processes and Materials, And Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China; National Key Laboratory of Water Environmental Simulation and Pollution Control, Guangdong Key Laboratory of Water and Air Pollution Control, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, No 18 Ruihe Road, Guangzhou, 510530, China
| | - Xianwei Wu
- School of Environment, Guangdong Engineering Research Center of Water Treatment Processes and Materials, And Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China
| | - Zhihong Liang
- The Pearl River Water Resources Research Institute, Guangzhou, 510611, China
| | - Yang Yu
- School of Environment, Guangdong Engineering Research Center of Water Treatment Processes and Materials, And Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China
| | - Guoqiang Liu
- School of Environment, Guangdong Engineering Research Center of Water Treatment Processes and Materials, And Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou, 510632, China.
| |
Collapse
|
10
|
Liu Y, Liu F, Ding N, Hu X, Shen C, Li F, Huang M, Wang Z, Sand W, Wang CC. Recent advances on electroactive CNT-based membranes for environmental applications: The perfect match of electrochemistry and membrane separation. CHINESE CHEM LETT 2020. [DOI: 10.1016/j.cclet.2020.03.011] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
11
|
Biofilm as a live and in-situ formed membrane for solids separation in bioreactors: Biofilm succession governs resistance variation demonstrated during the start-up period. J Memb Sci 2020. [DOI: 10.1016/j.memsci.2020.118197] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
|
12
|
Ripolles-Avila C, Ramos-Rubio M, Hascoët AS, Castillo M, Rodríguez-Jerez JJ. New approach for the removal of mature biofilms formed by wild strains of Listeria monocytogenes isolated from food contact surfaces in an Iberian pig processing plant. Int J Food Microbiol 2020; 323:108595. [PMID: 32224347 DOI: 10.1016/j.ijfoodmicro.2020.108595] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 02/20/2020] [Accepted: 03/18/2020] [Indexed: 12/15/2022]
Abstract
One of the main objectives of the food industry is to guarantee food safety by providing innocuous food products. Therefore, this sector must consider all the possible biotic or abiotic contamination routes from the entry of raw materials to the release of the final product. Currently, one important problem in this regard is the presence of biofilms on food contact surfaces which can transmit pathogens such as L. monocytogenes. In industrial conditions biofilms are found in a mature state, so it is essential that when carrying out removal effectiveness studies in vitro the tests are realized with models that produce these structures in a similarly mature state. The main objective of this study was to evaluate the effectiveness of an alternative treatment (i.e. enzymatic detergent that include natural antimicrobial agents) and a conventional treatment (i.e. chlorinated alkaline) for the elimination of mature L. monocytogenes biofilms. The results showed a cell detachment from the formed mature biofilms with an effectivity of between 74.75%-97.73% and 53.94%-94.02% for the enzymatic treatment and the chlorinated alkaline detergent, respectively. On a qualitative level, it was observed that the dispersion in the structure was much higher for the enzymatic treatment than for the chlorinated alkaline, which continued to show obvious structure integrity. All this leads to the conclusion that treatments with an enzymatic detergent have a significantly greater impact on the removal of mature L. monocytogenes biofilms, although a further disinfection process would be needed, enhancing even more the treatment effectivity. This may imply that the industrial approach to addressing this problem should be modified to include new perspectives that are more effective than traditional ones.
Collapse
Affiliation(s)
- C Ripolles-Avila
- Area of Human Nutrition and Food Science, Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), CP 08193 Barcelona, Spain
| | - M Ramos-Rubio
- Area of Human Nutrition and Food Science, Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), CP 08193 Barcelona, Spain
| | - A S Hascoët
- Area of Human Nutrition and Food Science, Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), CP 08193 Barcelona, Spain
| | - M Castillo
- Area of Human Nutrition and Food Science, Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), CP 08193 Barcelona, Spain
| | - J J Rodríguez-Jerez
- Area of Human Nutrition and Food Science, Departament de Ciència Animal i dels Aliments, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra (Cerdanyola del Vallès), CP 08193 Barcelona, Spain.
| |
Collapse
|
13
|
Ghalamchi L, Aber S, Vatanpour V, Kian M. Development of an antibacterial and visible photocatalytic nanocomposite microfiltration membrane incorporated by Ag3PO4/CuZnAl NLDH. Sep Purif Technol 2019. [DOI: 10.1016/j.seppur.2019.05.104] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
14
|
Zhu X, Jassby D. Electroactive Membranes for Water Treatment: Enhanced Treatment Functionalities, Energy Considerations, and Future Challenges. Acc Chem Res 2019; 52:1177-1186. [PMID: 31032611 DOI: 10.1021/acs.accounts.8b00558] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
To meet the increasing demand for water, potable water providers are turning toward unconventional waters, such as seawater and wastewater. These highly saline and/or heavily contaminated water sources are difficult to treat, demanding the use of advanced technology not typically used to treat conventional water sources such as river water or fresh groundwater. Of these advanced technologies, membrane separation processes are fast becoming the most widely used methods to convert these marginal waters into useful resources. The main factors contributing to the widespread adoption of membrane separation processes for water treatment include their modular nature, small physical footprint, and relative energy efficiency compared to traditional distillation processes. In addition, membranes present a physical barrier to pathogens, which is an attractive feature in terms of disinfection credits. However, traditional membrane materials suffer from several distinct drawbacks, which include membrane fouling (the accumulation of material on the membrane surface that blocks the flow of water), the need for high-pressure membranes (such as reverse osmosis (RO) or nanofiltration (NF)) or membrane/thermal processes (e.g., membrane distillation (MD)) to remove small contaminant compounds (e.g., trace metals, salt, endocrine disrupting compounds), and a pressure-driven membrane's inability to effectively remove small, uncharged molecules (e.g., N-nitrosodimethylamine (NDMA), phenol, acetone, and boron). Electrically driven physical and chemical phenomena, such as electrophoresis, electrostatic repulsion, dielectrophoresis, and electricity-driven redox reactions, have long been coupled to membrane-based separation processes, in a process known as electrofiltration. However, it is only in recent years that appropriate membrane materials (i.e., electrically conducting membranes (EMs)) have been developed that enable the efficient use of these electro-driven processes. Specifically, the development of EM materials (both polymeric and inorganic) have reduced the energy consumption of electrofiltration by using the membrane as an electrode in an electrochemical circuit. In essence, a membrane-electrode allows for the concentrated delivery of electrical energy directly to the membrane/water interface where the actual separation process takes place. In the past, metal electrodes were placed on either side of the membrane, which resulted in large potentials needed to drive electrochemical/electrokinetic phenomena. The use of a membrane-electrode dramatically reduces the required potentials, which reduces energy consumption and can also eliminate electrocorrosion and the formation of undesirable byproducts. In this Account, we review recent developments in the field of electrofiltration, with a focus on two water treatment applications: desalination and water reuse (wastewater or contaminated groundwater recycling). Specifically, we discuss how EMs can be used to minimize multiple forms of fouling (biofouling, mineral scaling, organic fouling); how electrochemical reactions at the membrane/water interface are used to destroy toxic contaminants, clean a membrane surface, and transform the local pH environment, which enhances the rejection of certain contaminants; how electric fields and electrostatic forces can be used to reorient molecules at the membrane/water interface; and how electrical energy can be transformed into thermal energy to drive separation processes. A special emphasis is placed on explicitly defining the additional energy consumption associated with the electrochemical phenomena, as well as the additional cost associated with fabricating EM materials. In addition, we will discuss current limitations of the electrofiltration process, with particular attention given to the current limitations of membrane materials and the future research needs in the area of membrane materials and module development.
Collapse
Affiliation(s)
- Xiaobo Zhu
- Department of Civil and Environmental Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - David Jassby
- Department of Civil and Environmental Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States
| |
Collapse
|
15
|
Li C, Guo X, Wang X, Fan S, Zhou Q, Shao H, Hu W, Li C, Tong L, Kumar RR, Huang J. Membrane fouling mitigation by coupling applied electric field in membrane system: Configuration, mechanism and performance. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.06.150] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|