Microbial removal and integrity monitoring of ro and NF Membranes

Kitiş, Mehmet; Lozier, James C.; Kim, Jae Hong; Mi, Baoxia; Mariñas, Benito J.

doi:10.1002/j.1551-8833.2003.tb10515.x

Cited by 47 publications

(42 citation statements)

References 4 publications

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“…MS2 was replicated and purified as described previously [29][30][31][32][33] with the following modifications . Select experiments were also performed using rotavirus (RV) to verify MS2 results.…”

Section: Virus Selection and Assaymentioning

confidence: 99%

Iron oxide amended biosand filters for virus removal

et al. 2011

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Laboratory studies were performed to determine if the addition of iron oxides throughout biosand filter (BSF) media would increase virus removal due to adsorption.The proposed mechanism is electrostatic adsorption of negatively charged virion particles to positively charged iron oxides formed during the corrosion of zerovalent iron. Initial tests conducted using continuous flow, small-scale glass columns showed high MS2 bacteriophage removal in an iron-amended sand column (5-log 10 ) compared to a sand only column (0.5-log 10 ) over 20 pore volumes. Additionally, two experiments with a column containing iron particles revealed 4 and 5 log 10 removal of rotavirus in the presence of 20 mg/L total organic carbon. Full-scale BSFs with iron particles removed >4-log 10 MS2 for the duration of the experiment (287 days), while BSF with steel wool removed >4-log 10 MS2 for the first 160 days. Plug flow for the BSF was shown to depend on uniformity between the iron oxide material and sand media grains. The results suggest that the duration of effective virus removal by iron-amended biosand filtration depends on source water conditions and the quantity and composition of iron material added. Overall, this study provides evidence that iron-amended BSFs may advance the field of point-of-use technologies and bring relief to millions of people suffering from waterborne diseases.iii ACKNOWLEDGMENTS

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Section: Virus Selection and Assaymentioning

confidence: 99%

Iron oxide amended biosand filters for virus removal

et al. 2011

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“…Although RO membranes should demonstrate LRV of 4 and higher for virus removal, public health protection concerns as well as regulatory requirements have spurned an intense search for real-time method of RO membrane integrity monitoring (MIM) [2,4]. At present, however, reliable real-time RO MIM methods are unavailable to detect membrane or module breaches that could potentially allow leakage of pathogens.…”

mentioning

confidence: 99%

“…The use of markers (e.g., bacteriophages or fluorescent markers) for membrane integrity testing has also been proposed [4,23]. This approach is particularly appealing since marker-based methods can be deployed in real-time using a wide-array of possible markers to provide detection at trace levels [4,10].…”

mentioning

confidence: 99%

“…At present, however, reliable real-time RO MIM methods are unavailable to detect membrane or module breaches that could potentially allow leakage of pathogens. The lack of real-time RO MIM has been often cited as the main reason that RO membranes are not given the 4 LRV credit for virus removal [2,4,5], primarily due to concerns with the occurrence of membrane or membrane module breaches that may go undetected.…”

mentioning

confidence: 99%

“…Indirect MIM methods, which rely on feed and permeate water quality parameters (e.g., particle counting [13][14][15][16], turbidity [12], conductivity [4,10,12,14], TOC [12,14,15], and sulfate monitoring [12]), have been utilized to monitor integrity of low pressure membrane (LPM) processes (e.g., microfiltration (MF) and ultrafiltration (UF)). Indirect MIM approaches, such as particle counting and turbidity monitoring, have successfully verified high LRV (up to 4 for MF and 5 for UF) in LPM processes [17,18], thus contributing to their regulatory acceptance with respect to virus removal.…”

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confidence: 99%

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Pulsed marker method for real-time detection of reverse osmosis membrane integrity loss

et al. 2015

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Removal of MS‐2 coliphage in full‐scale reverse osmosis systems

Vickers¹,

Dummer²,

Le³

et al. 2019

AWWA Water Science

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Recent activity in the potable reuse field will incorporate reverse osmosis (RO) processes that will be required to provide pathogen removal. The California State Water Resources Control Board has implemented a 12-10-10 log removal value (LRV) requirement for viruses, Giardia, and Cryptosporidium for groundwater recharge projects. Depending on the details of a Surface Water Source Augmentation Project, new regulations in 2018 specify an additional log reduction requirement up to a total of 14-12-12. Regulatory requirements that specify a treatment technique (e.g., RO) and establish log removal requirements for treatment trains are being implemented. Surrogate indicators such as electrical conductivity (EC) and total organic carbon (TOC) reduction are currently being used as online indicators to determine compliance of RO systems. The actual virus removal through a full-scale operating system is something that has not been extensively characterized. Most of the information that exists for testing with viruses is associated with bench-or pilot-scale evaluations. Evaluations of permeate from full-scale RO systems operating with wastewater effluent as the source water indicate that viruses are not present; however, concerns remain about the potential loss of integrity through the RO system. Under the regulatory criteria established in the US Environmental Protection Agency Membrane Filtration Guidance Manual for drinking water, bulk surrogate indicators such as EC or TOC lack the sensitivity to accurately measure the actual log reduction for pathogens. It is generally recognized that the feed water quality matrix can be variable in composition, which can also affect the measurement. Bulk surrogate indicators do not satisfy the criteria for being discretely quantifiable, a term that is synonymous with the indicator having a specific molecular weight or defined composition. While alternative chemical markers such as fluorescence compounds, sulfate, or strontium yield higher LRVs, the methods are not easily implemented. An underlying issue with these indicators is that, because of their small size, they will also diffuse through the membrane and understate the pathogen removal that is occurring. An article presented in Journal AWWA proposes that the results of a conductivity profile can be used to increase the sensitivity and calculate a higher LRV. Using the dilution model as the underlying approach, the technique differentiates conductivity that would be associated with diffusion from conductivity that would be associated with a defect. Literature review

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Microbial removal and integrity monitoring of ro and NF Membranes

Cited by 47 publications

References 4 publications

Iron oxide amended biosand filters for virus removal

Iron oxide amended biosand filters for virus removal

Pulsed marker method for real-time detection of reverse osmosis membrane integrity loss

Removal of MS‐2 coliphage in full‐scale reverse osmosis systems

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