Membrane Integrity Monitoring

Gitis, Vitaly; Rothenberg, Gadi

doi:10.1002/9781118522318.emst067

Cited by 5 publications

(5 citation statements)

References 47 publications

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“…Because achieving a sterile effluent is of critical importance, sterilizing-grade filters are typically integrity-tested after assembly and prior to use, as well as again after use, as per industry and regulatory guidelines [ 1 , 2 , 3 ]. Several types of integrity tests for assessing the integrity of membrane filters for liquid filtration have been previously described, including particle challenge tests, the gas–liquid diffusion test, the bubble point test, and diffusion tests measuring tracer components [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. Of these, variants of the gas–liquid diffusion test (gas–liquid pair combinations such as air–water, nitrogen–IPA, and others, along with the diffusive–forward flow and pressure hold–decay measurement methods) and bubble-point-type tests are most commonly used for sterilizing-grade filters [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]…”

Section: Introductionmentioning

confidence: 99%

Defect Detection Sensitivity of Bubble-Point-Type Tests for Sterilizing-Grade Membrane Cartridge Filters

Giglia¹,

Alembath²,

Hersey³

2023

Membranes

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Bubble point tests are widely used for assessing the integrity of sterilizing-grade membrane cartridge filters. While many authors have considered the limitations of bubble point tests as applied to cartridge filters, the level of bacterial retention assurance provided by this test as conducted with automated integrity testers (AITs) has not, until now, been quantified. Contrary to the notion that filter leaks result in a depressed bubble point, it was shown that the bubble point as reported by AITs was insensitive to defect size up until the point where the AIT either determined a gross leak failure or was not able to return a valid result. For the three AITs used in this study, the minimum laser hole defect diameter in 10-inch (25.4 cm) sterilizing-grade cartridge filters that resulted in a failing bubble point test was between about 30 and 60 µm, depending on the filter type and test conditions. These defect sizes were associated with bacterial log reduction values in the 4.0 to 4.5 range. This study supports the generally recommended practice of pairing the bubble point test (which does confirm proper pore size rating) with a complementary gas–liquid diffusion test (better suited for detecting defects) to achieve a more comprehensive assessment of filter integrity.

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Section: Introductionmentioning

confidence: 99%

Defect Detection Sensitivity of Bubble-Point-Type Tests for Sterilizing-Grade Membrane Cartridge Filters

Giglia¹,

Alembath²,

Hersey³

2023

Membranes

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“…Several indirect monitoring methods have been proposed by previous research. ,,,− Among physicochemical surrogate indicators, turbidity measurements and particle counting are regularly applied for indirect monitoring . While these methods are quick and relatively inexpensive, limited sensitivity due to low concentrations leaves them less applicable in high-pressure membrane processes. , Conductivity and ion retention were also implemented to monitor membrane integrity. While able to be monitored online with LRVs up to log 3, sufficiently high concentrations are required to observe integrity losses .…”

Section: Introductionmentioning

confidence: 99%

“… 21 While these methods are quick and relatively inexpensive, limited sensitivity due to low concentrations leaves them less applicable in high-pressure membrane processes. 22 , 23 Conductivity and ion retention were also implemented to monitor membrane integrity. While able to be monitored online with LRVs up to log 3, sufficiently high concentrations are required to observe integrity losses.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Membrane Integrity Monitoring Methods for Hollow Fiber Nanofiltration Membranes: Applicability in Gray Water Reclamation Systems

Rutten,

Ojobe,

Hernández Leal

et al. 2023

ACS EST Water

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Source-separated gray water reclamation using nanofiltration as an advanced post-treatment option has received substantial interest in meeting the growing water demand. During reclamation, membrane integrity is crucial to ensure the water’s safety. This study evaluated several chemical and novel microbial indicators as indirect membrane integrity-monitoring methods for hollow fiber nanofiltration membranes in reclamation schemes. Under normal conditions, high retention of divalent ions and organic matter and near-complete removal of Escherichia coli (E. coli) were observed. Limited removal of the antibiotic gene (ARG) tetO was observed due to low feed concentrations and a higher detection limit (LOD). While 16S rRNA and ARG sul1 were not limited by their LODs, lower removals were observed, most likely due to free-floating DNA passing through the membranes. A broken fiber in a pilot-scale module reduced organic matter and microorganism removal substantially, while flux and ion rejection remained similar. Predictions made using the observed results and a previously proposed model allowed for the evaluation of the selected methods in upscaled reclamation systems. Based on these results, it was concluded that microorganisms could be employed as indicators in indirect membrane integrity-monitoring methods in large-scale reclamation schemes, while UV254nm absorbance (used in organic matter determination) could be a viable solution in pilot-scale systems.

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“…Several indirect monitoring methods have been proposed by previous research (Antony et al, 2012;Buysschaert et al, 2018;Gitis and Rothenberg, 2013;Huang et al, 2015;Krahnstöver et al, 2019;Lidén et al, 2016;Lousada-Ferreira et al, 2016;Ostarcevic et al, 2018;van Nevel et al, 2017). Among physicochemical surrogate indicators, turbidity measurements, and particle counting are regularly applied for indirect monitoring (Lousada-Ferreira et al, 2016).…”

Section: Abrahamsementioning

confidence: 99%

“…Among physicochemical surrogate indicators, turbidity measurements, and particle counting are regularly applied for indirect monitoring (Lousada-Ferreira et al, 2016). While these methods are quick and relatively inexpensive, limited sensitivity due to low concentrations leaves them less applicable in high-pressure membrane processes (Antony et al, 2012;Gitis and Rothenberg, 2013). Conductivity and ion retention have also been implemented to monitor membrane integrity.…”

Section: Abrahamsementioning

confidence: 99%

Nanofiltration of Greywater to Remove Micropollutants

Rutten

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Global freshwater resources are currently experiencing increasingly high stress due to extreme weather events brought along by climate change and the evergrowing global population. To protect these natural resources while simultaneously meeting the growing global water demand, local solutions, such as the reclamation of domestically produced wastewater, have gained interest.When considering wastewater reclamation, implementing source-separated sanitation concepts, where toilet water (blackwater) is separately collected from all other sources of domestic water (greywater), can enhance the ease of recovery of nutrients, energy, and water. Effective biological greywater treatment systems have been developed and implemented in the past decades, opening the door to the potential reuse of this stream has limited the full-scale adoption of greywater treatment plants for water reclamation. Micropollutants consist of a large group of natural and anthropogenic substances with a molecular weights up to 800 g.mol -1 , such as pharmaceuticals like diclofenac and personal care products like galaxolide. These substances are found at trace concentration (ng.L -1 -µg.L -1 ) in wastewater and could have potential detrimental effects on the environment when discharged. Therefore, advanced post-treatment solutions are required to reduce the continuous discharge of micropollutants by treatment plants and limit the risks posed by these substances during reuse. One promising post-treatment technology is the use of hollow fiber nanofiltration membranes.These newly developed membranes have proven to be effective barriers for micropollutants in lab-scale experiments and have recently become commercially available for large-scale applications. However, translating these lab-scale results, which were mainly performed using synthetic water matrices, to realworld applications is not straightforward. Further knowledge needs to be acquired to determine the role these membranes can play in greywater treatment systems. General Introduction1.1. Water as an essential resource 1.2. Greywater 1.3. Pressure driven membrane processes 1.4. Polyelectrolyte multilayer based nanofiltration membranes 1.5. Implementation of hollow fiber nanofiltration in greywater treatment 1.6. Thesis outline 2. Influence of dominant salts on the removal of trace micropollutants by hollow fiber nanofiltration Abstract 2.1. Introduction 2.2. Materials and Methods 2.3. Results and Discussion 2.4. Conclusion 3. Retention of micropollutants by polyelectrolyte multilayer based hollow fiber nanofiltration membranes under fouled conditions Abstract 3.1. Introduction 3.2. Materials and Methods 3.3. Results and Discussion 3.4. Conclusions and Outlook xiv 4. Evaluation of membrane integrity monitoring methods for hollow fiber nanofiltration membranes: applicability in greywater reclamation systems Abstract 4.1. Introduction 4.2. Materials and Methods 4.3. Results and Discussion 4.4. Conclusion 5. One year experience with advanced greywater treatment: the removal of micropollutants Ab...

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Membrane Integrity Monitoring

Cited by 5 publications

References 47 publications

Defect Detection Sensitivity of Bubble-Point-Type Tests for Sterilizing-Grade Membrane Cartridge Filters

Defect Detection Sensitivity of Bubble-Point-Type Tests for Sterilizing-Grade Membrane Cartridge Filters

Evaluation of Membrane Integrity Monitoring Methods for Hollow Fiber Nanofiltration Membranes: Applicability in Gray Water Reclamation Systems

Nanofiltration of Greywater to Remove Micropollutants

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