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Phuna ZX, Panda BP, Hawala Shivashekaregowda NK, Madhavan P. Nanoprotection from SARS-COV-2: would nanotechnology help in Personal Protection Equipment (PPE) to control the transmission of COVID-19? INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2022:1-30. [PMID: 35253535 DOI: 10.1080/09603123.2022.2046710] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 02/21/2022] [Indexed: 06/14/2023]
Abstract
The coronavirus disease 2019 (COVID-19) has caused a worldwide outbreak. The severe acute respiratory syndrome coronavirus 2 virus can be transmitted human-to-human through droplets and close contact where personal protective equipment (PPE) is imperative to protect the individuals. The advancement of nanotechnology with significant nanosized properties can confer a higher form of protection. Incorporation of nanotechnology into facemasks can exhibit antiviral properties. Nanocoating on surfaces can achieve self-disinfecting purposes and be applied in highly populated places. Moreover, nano-based hand sanitizers can confer better sterilizing efficacies with low skin irritation as compared to alcohol-based hand sanitizers. The present review discusses the incorporation of nanotechnology into nano-based materials and coatings in facemasks, self-surface disinfectants and hand sanitizers, in the hope to contribute to the current understanding of PPE to combat COVID-19.
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Affiliation(s)
- Zhi Xin Phuna
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Selangor, Malaysia
| | - Bibhu Prasad Panda
- Department of Pharmaceutical Technology, Schoolof Pharmacy, Faculty of Health & Medical Sciences, Taylor's University, Subang Jaya, Malaysia
| | | | - Priya Madhavan
- School of Medicine, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Selangor, Malaysia
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2
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The influence of various orifice diameters on cake resistance and pore blocking resistance of a hybrid membrane photobioreactor (HMPBR). Sep Purif Technol 2020. [DOI: 10.1016/j.seppur.2019.116187] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Optimizing Flux Capacity of Dead-end Filtration Membranes by Controlling Flow with Pulse Width Modulated Periodic Backflush. Sci Rep 2020; 10:896. [PMID: 31964959 PMCID: PMC6972749 DOI: 10.1038/s41598-020-57649-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 12/23/2019] [Indexed: 11/08/2022] Open
Abstract
Standard dead-end sample filtration is used to improve sample purity, but is limited as particle build-up fouls the filter, leading to reduced recovery. The fouling layer can be periodically cleared with backflush algorithms applied through a customized fluidic actuator using variable duty cycles, significantly improving particulate recovery percentage. We show a Pulse Width Modulation (PWM) process can periodically backflush the filter membrane to repeatedly interrupt cake formation and reintegrate the fouling layer into the sample, improving net permeate flux per unit volume of sample by partially restoring filter flux capacity. PWM flow for 2.19 um (targeted) and 7.32 um (untargeted) polystyrene microbeads produced 18-fold higher permeate concentration, higher recovery up to 68.5%, and an 8-fold enrichment increase, compared to a uniform flow. As the duty cycle approaches 50%, the recovery percentage monotonically increases after a critical threshold. Further, we developed and validated a mathematical model to determine that fast, small-volume backflush pulses near 50% duty cycle yield higher recovery by decreasing fouling associated with the cake layer. Optimized PWM flow was then used to purify custom particles for immune activation, achieving 3-fold higher recovery percentage and providing a new route to improve purification yields for diagnostic and cellular applications.
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Martí-Calatayud MC, Schneider S, Yüce S, Wessling M. Interplay between physical cleaning, membrane pore size and fluid rheology during the evolution of fouling in membrane bioreactors. WATER RESEARCH 2018; 147:393-402. [PMID: 30336342 DOI: 10.1016/j.watres.2018.10.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 09/19/2018] [Accepted: 10/05/2018] [Indexed: 06/08/2023]
Abstract
Fouling is one of the most pressing limitations during operation of membrane bioreactors, as it increases operating costs and is the cause of short membrane lifespans. Conducting effective physical cleanings is thus essential for keeping membrane operation above viable performance limits. The nature of organic foulants present in the sludge and the membrane properties are among the most influential factors determining fouling development and thus, efficiency of fouling mitigation approaches. The role of other factors like sludge viscosity on fouling is still unclear, given that contradictory effects have been reported in the literature. In the present study we use a new research approach by which the complex interplay between fouling type, levels of permeate flux, membrane material and feed properties is analyzed, and the influence of these factors on critical flux and membrane permeability is evaluated. A variety of systems including activated sludge and model solutions with distinct rheological behavior has been investigated for two membranes differing in pore size distribution. We present a novel method for assessing the efficiency of fouling removal by backwash and compare it with the efficiency achieved by means of relaxation. Results obtained have proven that backwash delays development of critical fouling as compared with relaxation and reduces fouling irreversibility regardless of fluid rheology. It was shown that backwash is especially effective for membranes for which internal fouling is the main cause of loss in permeability. Nonetheless, we found out that for membranes with tight pores, both relaxation and backwash are equally effective. The critical flux decreases significantly for high-viscosity fluids, such as activated sludge. This effect is mainly caused by an intensified concentration polarization at the feed side rather than by internal fouling events. However, membrane permeability has been proven to rely more on the permeate viscosity than on the feed viscosity: poor rejection of organic fractions showcasing high viscosity causes an acute decline in membrane permeability as a consequence of increased shear stress inside the membrane pores.
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Affiliation(s)
- M C Martí-Calatayud
- Universitat Politècnica de València, IEC Group, Departament d'Enginyeria Quimica i Nuclear, Camí de Vera s/n, 46022, València, Spain; RWTH Aachen University, Chemical Process Engineering, Forckenbeckstr. 51, 52074, Aachen, Germany.
| | - S Schneider
- RWTH Aachen University, Chemical Process Engineering, Forckenbeckstr. 51, 52074, Aachen, Germany
| | - S Yüce
- RWTH Aachen University, Chemical Process Engineering, Forckenbeckstr. 51, 52074, Aachen, Germany
| | - M Wessling
- RWTH Aachen University, Chemical Process Engineering, Forckenbeckstr. 51, 52074, Aachen, Germany; DWI Interactive Materials Research, Forckenbeckstr. 50, 52074, Aachen, Germany.
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Sima XF, Wang YY, Shen XC, Jing XR, Tian LJ, Yu HQ, Jiang H. Robust biochar-assisted alleviation of membrane fouling in MBRs by indirect mechanism. Sep Purif Technol 2017. [DOI: 10.1016/j.seppur.2017.04.046] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Demirkol GT, Dizge N, Acar TO, Salmanli OM, Tufekci N. Influence of nanoparticles on filterability of fruit-juice industry wastewater using submerged membrane bioreactor. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2017; 76:705-711. [PMID: 28759452 DOI: 10.2166/wst.2017.255] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this study, polyethersulfone (PES) ultrafiltration membrane surface was modified with nano-sized zinc oxide (nZnO) and silver (nAg) to improve the membrane filterability of the mixed liquor and used to treat fruit-juice industry wastewater in a submerged membrane bioreactor (MBR). The nAg was synthesized using three different methods. In the first method, named as nAg-M1, PES membrane was placed on the membrane module and nAg solution was passed through the membrane for 24 h at 25 ± 1 °C. In the second method, named as nAg-M2, PES membrane was placed in a glass container and it was shaken for 24 h at 150 rpm at 25 ± 1 °C. In the third method, named as nAg-M3, Ag nanoparticles were loaded onto PES membrane in L-ascorbic acid solution (0.1 mol/L) at pH 2 for 24 h at 150 rpm at 25 ± 1 °C. For the preparation of nZnO coated membrane, nZnO nanoparticles solution was passed through the membrane for 24 h at 25 ± 1 °C. Anti-fouling performance of pristine and coated membranes was examined using the submerged MBR. The results showed that nZnO and nAg-M3 membranes showed lower flux decline compared with pristine membrane. Moreover, pristine and coated PES membranes were characterized using a permeation test, contact angle goniometer, and scanning electron microscopy.
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Affiliation(s)
- Guler Turkoglu Demirkol
- Department of Environmental Engineering, Istanbul University, Istanbul 34320, Turkey E-mail:
| | - Nadir Dizge
- Department of Environmental Engineering, Mersin University, Mersin 33343, Turkey
| | - Turkan Ormanci Acar
- Department of Environmental Engineering, Istanbul University, Istanbul 34320, Turkey E-mail:
| | - Oyku Mutlu Salmanli
- Department of Environmental Engineering, Istanbul Technical University, Istanbul 34469, Turkey
| | - Nese Tufekci
- Department of Environmental Engineering, Istanbul University, Istanbul 34320, Turkey E-mail:
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Sabia G, Ferraris M, Spagni A. Model-based analysis of the effect of different operating conditions on fouling mechanisms in a membrane bioreactor. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:1598-1609. [PMID: 26377972 DOI: 10.1007/s11356-015-5372-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 09/04/2015] [Indexed: 06/05/2023]
Abstract
This study proposes a model-based evaluation of the effect of different operating conditions with and without pre-denitrification treatment and applying three different solids retention times on the fouling mechanisms involved in membrane bioreactors (MBRs). A total of 11 fouling models obtained from literature were used to fit the transmembrane pressure variations measured in a pilot-scale MBR treating real wastewater for more than 1 year. The results showed that all the models represent reasonable descriptions of the fouling processes in the MBR tested. The model-based analysis confirmed that membrane fouling started by pore blocking (complete blocking model) and by a reduction of the pore diameter (standard blocking) while cake filtration became the dominant fouling mechanism over long-term operation. However, the different fouling mechanisms occurred almost simultaneously making it rather difficult to identify each one. The membrane "history" (i.e. age, lifespan, etc.) seems the most important factor affecting the fouling mechanism more than the applied operating conditions. Nonlinear regression of the most complex models (combined models) evaluated in this study sometimes demonstrated unreliable parameter estimates suggesting that the four basic fouling models (complete, standard, intermediate blocking and cake filtration) contain enough details to represent a reasonable description of the main fouling processes occurring in MBRs.
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Affiliation(s)
- Gianpaolo Sabia
- ENEA, Water Resources Management Laboratory, via M.M. Sole, 4, 40129, Bologna, Italy
| | - Marco Ferraris
- ENEA, Water Resources Management Laboratory, via M.M. Sole, 4, 40129, Bologna, Italy.
| | - Alessandro Spagni
- ENEA, Water Resources Management Laboratory, via M.M. Sole, 4, 40129, Bologna, Italy
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Alibardi L, Cossu R, Saleem M, Spagni A. Development and permeability of a dynamic membrane for anaerobic wastewater treatment. BIORESOURCE TECHNOLOGY 2014; 161:236-244. [PMID: 24709537 DOI: 10.1016/j.biortech.2014.03.045] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 03/06/2014] [Accepted: 03/10/2014] [Indexed: 06/03/2023]
Abstract
Dynamic membranes (DMs) have recently been proposed as an alternative to microfiltration and ultrafiltration in membrane bioreactors (MBRs) in order to contain capital and management costs. This study aims to develop an anaerobic dynamic MBR for wastewater treatment by using a large pore-sized mesh. The study demonstrated that a DM can be developed by using a mesh of 200μm pore-size and applying low cross flow velocity. The bench-scale reactor achieved COD removal efficiency between 65% and 92% and proved to be able to remove approximately 99% of the mixed liquor suspended solids, maintaining a solids retention time well above 200d. A significant quantity of biogas was produced by the external dynamic membrane module and was released with the effluent stream. The flux-step experiment, designed to estimate the critical flux in ultrafiltration MBR, can also be used for monitoring the development and stability of DMs.
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Affiliation(s)
- Luca Alibardi
- Department of Civil, Environmental and Architectural Engineering, University of Padova, via Marzolo 9, 35131 Padova, Italy
| | - Raffaello Cossu
- Department of Industrial Engineering, University of Padova, via Marzolo 9, 35131 Padova, Italy
| | - Mubashir Saleem
- Department of Civil, Environmental and Architectural Engineering, University of Padova, via Marzolo 9, 35131 Padova, Italy
| | - Alessandro Spagni
- Water Resources Management Laboratory, Italian National Agency for New Technology, Energy and Sustainable Economic Development (ENEA), via M.M. Sole 4, 40129 Bologna, Italy.
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