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Mamba PP, Msagati TAM, Mamba BB, Motsa MM, Nkambule TTI. The removal of pathogenic bacteria and dissolved organic matter from freshwater using microporous membranes: insights into biofilm formation and fouling reversibility. BIOFOULING 2024; 40:245-261. [PMID: 38639133 DOI: 10.1080/08927014.2024.2339438] [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: 06/19/2023] [Accepted: 04/01/2024] [Indexed: 04/20/2024]
Abstract
Pathogenic bacteria in drinking-water pose a health risk to consumers, as they compromise the quality of portable water. Chemical disinfection of water containing dissolved organic matter (DOM) causes harmful disinfection by-products. In this work, 4-hydroxybenzoic acid (4-HBA) blended polyethersulfone membranes were fabricated and characterised using microscopic and spectroscopic techniques. The membranes were evaluated for the removal of bacteria and DOM from synthetic and environmental water. Permeate flux increased from 287.30 to 374.60 l m-2 h-1 at 3 bars when 4-HBA increased from 0 to 1.5 wt.%, suggesting that 4-HBA influenced the membrane's affinity for water. Furthermore, 4-HBA demonstrated antimicrobial properties by inhibiting bacterial growth. The membrane with 1 wt.% 4-HBA recorded 99.4 and 100% bacteria removal in synthetic and environmental water, respectively. Additionally, DOM removal of 55-73% was achieved. A flux recovery ratio (FRR) of 94.6% was obtained when a mixture of bacteria and humic acid was filtered, implying better fouling layer reversibility during cleaning. Furthermore, 100% FRR was achieved when a multimedia granular filtration step was installed prior to membrane filtration. The results illustrated that the membranes had a high permeate flux with low irreversible fouling. This indicated the potential of the membranes in treating complex feed streams using simple cleaning protocols.
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Affiliation(s)
- Phumlile P Mamba
- Institute for Nanotechnology and Water Sustainability (iNanoWS), College of Science, Engineering and Technology, University of South Africa, Science Campus, Florida, Johannesburg, South Africa
| | - Titus A M Msagati
- Institute for Nanotechnology and Water Sustainability (iNanoWS), College of Science, Engineering and Technology, University of South Africa, Science Campus, Florida, Johannesburg, South Africa
| | - Bhekie B Mamba
- Institute for Nanotechnology and Water Sustainability (iNanoWS), College of Science, Engineering and Technology, University of South Africa, Science Campus, Florida, Johannesburg, South Africa
| | - Machawe M Motsa
- Institute for Nanotechnology and Water Sustainability (iNanoWS), College of Science, Engineering and Technology, University of South Africa, Science Campus, Florida, Johannesburg, South Africa
| | - Thabo T I Nkambule
- Institute for Nanotechnology and Water Sustainability (iNanoWS), College of Science, Engineering and Technology, University of South Africa, Science Campus, Florida, Johannesburg, South Africa
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Aouni A, Tounakti R, Ahmed BA, Hafiane A. Hybrid electrochemical/membrane couplings processes for enhancing seawater pretreatment and desalination. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2024; 96:e10979. [PMID: 38264925 DOI: 10.1002/wer.10979] [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: 07/11/2023] [Revised: 10/28/2023] [Accepted: 12/22/2023] [Indexed: 01/25/2024]
Abstract
This research focuses on boosting seawater pretreatment and desalination through electrocoagulation (EC)/ultrafiltration (UF) and electrocoagulation (EC)/nanofiltration (NF) processes. We first optimized the key parameters of the EC process using aluminum (Al) and iron (Fe) electrodes. Experimental results show EC process is efficient under optimal conditions. Second, membrane filtration using UF (ES10B), NF(UTC60) and NF(200) as post-processing steps to the EC process were experimented with. EC(Al)/NF(UTC60) combination resulted in the highest removal rate of organic matter (COD 98%, TOC 95%, fluorescence [humic and fulvic acids] 68%), optical density (OD600nm 75%, turbidity 70%, conductivity 64%). In terms of major ions removal, up to 55% was achieved as NF decreases conductivity, salinity, and hardness. EC(Al)/NF(UTC60) seawater permeate demonstrated the best results in terms of lowest flux decline (J/Jo = 0.9) and fouling, which was realized by resistance in series and recovery factor rate (%). Additionally, NF(UTC60) fouling reversibility led to a longer lifetime and higher recovery factor (93%). PRACTITIONER POINTS: Pretreatment by hybrid processes was experimented with to enhance the saline water treatment. Organic matter (COD 98%, TOC 95%, fluorescence [humic and fulvic acids] 68%) and turbidity were successfully removed. Salinity and hardness (conductivity 64%) were highly reduced by NF. Flux decline, retention rate, and membrane fouling were studied.
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Affiliation(s)
- Anissa Aouni
- Laboratory of Water, Membranes and Environmental Biotechnology, CERTE, Soliman, Tunisia
| | - Rim Tounakti
- Laboratory of Water, Membranes and Environmental Biotechnology, CERTE, Soliman, Tunisia
| | - Badiaa Ait Ahmed
- Department of Computer Science Engineering, SIGL-Lab, ENSATe, Abdelmalek Essaadi University, Tetouan, Morocco
| | - Amor Hafiane
- Laboratory of Water, Membranes and Environmental Biotechnology, CERTE, Soliman, Tunisia
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Can Aggregate-Associated Organisms Influence the Fouling in a SWRO Desalination Plant? Microorganisms 2022; 10:microorganisms10040682. [PMID: 35456734 PMCID: PMC9032733 DOI: 10.3390/microorganisms10040682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/17/2022] [Accepted: 03/17/2022] [Indexed: 12/10/2022] Open
Abstract
This pilot study investigates the formation of aggregates within a desalination plant, before and after pre-treatment, as well as their potential impact on fouling. The objective is to provide an understanding of the biofouling potential of the feed water within a seawater reverse osmosis (SWRO) desalination plant, due to the limited removal of fouling precursors. The 16S and 18S rRNA was extracted from the water samples, and the aggregates and sequenced. Pre-treatment systems, within the plant remove < 5 µm precursors and organisms; however, smaller size particles progress through the plant, allowing for the formation of aggregates. These become hot spots for microbes, due to their nutrient gradients, facilitating the formation of niche environments, supporting the proliferation of those organisms. Aggregate-associated organisms are consistent with those identified on fouled SWRO membranes. This study examines, for the first time, the factors supporting the formation of aggregates within a desalination system, as well as their microbial communities and biofouling potential.
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Solcova O, Krystynik P, Dytrych P, Bumba J, Kastanek F. Typical groundwater contamination in the vicinity of industrial brownfields and basic methods of their treatment. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 233:113325. [PMID: 35182798 DOI: 10.1016/j.ecoenv.2022.113325] [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: 10/25/2021] [Revised: 02/01/2022] [Accepted: 02/15/2022] [Indexed: 06/14/2023]
Abstract
The article deals with simple methods of decontamination of groundwater from the vicinity of brownfields contaminated with organic and inorganic substances. In the literature, thousands of articles on this issue at various sophisticated levels of knowledge can be found. The articles are mostly suitable as an extension of scientific knowledge; however, regarding potential costs and respectively scale-up problems, the applications are limited. It turns out that the vast majority of contaminated water can be effectively decontaminated by simple methods, in a coagulation-sedimentation sequence → simple oxidation and reduction methods for separated water (Fenton reaction, photocatalysis, ozonation, reductive dehalogenation with zero metals) → adsorption of remaining pollutants on simple sorbents, eg on biochar → (possibly bioremediation or advanced physical methods such as membrane filtration) → final purification on activated carbon. Due to the usually limited volume loads of soils with pollutants in the vicinity of brownfields, it is not economically advantageous to build demanding decontamination units for water purification. Usually, the simplest solution is the system to pump-and-treat around the source of contamination, with the main emphasis on highly effective removal of pollutants from water that returns underground. Groundwater was taken from boreholes leading to the saturated zone in the vicinity of several selected industrial brownfields. The solutions are shown on individual typical cases.
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Affiliation(s)
- Olga Solcova
- Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic, Rozvojova 135, 165 02 Prague 6, Czech Republic
| | - Pavel Krystynik
- Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic, Rozvojova 135, 165 02 Prague 6, Czech Republic; Faculty of Environment, University of J. E. Purkyne, Pasteurova 3632/15, 400 96 Usti nad Labem, Czech Republic.
| | - Pavel Dytrych
- Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic, Rozvojova 135, 165 02 Prague 6, Czech Republic
| | - Jakub Bumba
- Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic, Rozvojova 135, 165 02 Prague 6, Czech Republic
| | - Frantisek Kastanek
- Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic, Rozvojova 135, 165 02 Prague 6, Czech Republic
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Chen Y, Li H, Pang W, Zhou B, Li T, Zhang J, Dong B. Pilot Study on the Combination of Different Pre-Treatments with Nanofiltration for Efficiently Restraining Membrane Fouling While Providing High-Quality Drinking Water. MEMBRANES 2021; 11:membranes11060380. [PMID: 34073651 PMCID: PMC8224806 DOI: 10.3390/membranes11060380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 05/14/2021] [Accepted: 05/17/2021] [Indexed: 11/16/2022]
Abstract
Nanofiltration (NF) is a promising post-treatment technology for providing high-quality drinking water. However, membrane fouling remains a challenge to long-term NF in providing high-quality drinking water. Herein, we found that coupling pre-treatments (sand filtration (SF) and ozone-biological activated carbon (O3-BAC)) and NF is a potent tactic against membrane fouling while achieving high-quality drinking water. The pilot results showed that using SF+O3-BAC pre-treated water as the feed water resulted in a lower but a slowly rising transmembrane pressure (TMP) in NF post-treatment, whereas an opposite observation was found when using SF pre-treated water as the feed water. High-performance size-exclusion chromatography (HPSEC) and three-dimensional excitation-emission matrix (3D-EEM) fluorescence spectroscopy determined that the O3-BAC process changed the characteristic of dissolved organic matter (DOM), probably by removing the DOM of lower apparent molecular weight (LMW) and decreasing the biodegradability of water. Moreover, amino acids and tyrosine-like substances which were significantly related to medium and small molecule organics were found as the key foulants to membrane fouling. In addition, the accumulation of powdered activated carbon in O3-BAC pre-treated water on the membrane surface could be the key reason protecting the NF membrane from fouling.
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Affiliation(s)
- Yan Chen
- School of the Environment and Municipal Administration, Lanzhou Jiaotong University, Lanzhou 730070, China; (H.L.); (J.Z.)
- Key Laboratory of Yellow River Water Environment in Gansu Province, Lanzhou Jiaotong University, Lanzhou 730070, China
- Correspondence:
| | - Huiping Li
- School of the Environment and Municipal Administration, Lanzhou Jiaotong University, Lanzhou 730070, China; (H.L.); (J.Z.)
- Key Laboratory of Yellow River Water Environment in Gansu Province, Lanzhou Jiaotong University, Lanzhou 730070, China
| | - Weihai Pang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; (W.P.); (T.L.); (B.D.)
| | - Baiqin Zhou
- School of Civil and Environmental Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen 518055, China;
| | - Tian Li
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; (W.P.); (T.L.); (B.D.)
| | - Jian Zhang
- School of the Environment and Municipal Administration, Lanzhou Jiaotong University, Lanzhou 730070, China; (H.L.); (J.Z.)
- Key Laboratory of Yellow River Water Environment in Gansu Province, Lanzhou Jiaotong University, Lanzhou 730070, China
| | - Bingzhi Dong
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; (W.P.); (T.L.); (B.D.)
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