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Real-Time Online Monitoring for Assessing Removal of Bacteria by Reverse Osmosis

  • Takahiro Fujioka*
    Takahiro Fujioka
    Water and Environmental Engineering, Graduate School of Engineering, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
    *E-mail: [email protected]. Telephone: +81 095 819 2695. Fax: +81 95 819 2620.
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    Orcidhttp://orcid.org/0000-0001-9111-5628
  • , 
  • Anh T. Hoang
    Anh T. Hoang
    Water and Environmental Engineering, Graduate School of Engineering, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
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  • , 
  • Hidenobu Aizawa
    Hidenobu Aizawa
    Environment Management Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan
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  • , 
  • Hiroki Ashiba
    Hiroki Ashiba
    Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
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  • , 
  • Makoto Fujimaki
    Makoto Fujimaki
    Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
    More by Makoto Fujimaki
  • , and 
  • Menu Leddy
    Menu Leddy
    Orange County Water District, 18700 Ward Street, Fountain Valley, California 92708, United States
    More by Menu Leddy
Cite this: Environ. Sci. Technol. Lett. 2018, 5, 6, 389–393
Publication Date (Web):April 26, 2018
https://doi.org/10.1021/acs.estlett.8b00200

Copyright © 2018 American Chemical Society. This publication is licensed under these Terms of Use.

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Abstract

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Rigorous monitoring of microbial water quality is essential to ensure the safety of recycled water after advanced treatment for indirect and direct potable reuse. This study evaluated real-time bacterial monitoring for assessing reverse osmosis (RO) treatment for removal of bacteria. A strategy was employed to monitor bacterial counts online and in real time in the RO feed and permeate water using a real-time continuous bacteriological counter. Over the course of 68 h pilot-scale testing, bacterial counts were monitored in real time over approximate ranges from 1 × 103 to 4 × 104 and from 4 to 342 counts/mL in the RO feed (ultrafiltration-treated wastewater) and permeate, respectively. The results indicate that the bacteriological counter can track the variations in bacterial counts in the RO feed and permeate. Bacterial concentrations were confirmed by epi-fluorescence microscopy for total bacterial counts. A high correlation (R2 = 0.83) was identified between the online bacterial counts and epi-fluorescence counts in the RO feed; a negligible correlation was observed for RO permeate. In this study, we evaluated a real-time bacteriological counter (i.e., counts per milliliter every second) to ensure continuous removal of bacterial contaminants by RO treatment.

Introduction

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Potable reuse (PR) has been increasingly used to augment potable water supplies in arid regions. (1,2) Potable reuse turns treated wastewater effluent into potable water; thus, the assurance of safety and reliability in recycled water quality, particularly microbiological quality, is a critical component for public health protection. This is especially important for direct potable reuse (DPR), in which highly treated wastewater at advanced water treatment plants (AWTPs) is directly used as a potable water source without going through an environmental buffer. (3) At AWTPs, a reverse osmosis (RO) membrane process can have an important role in removing most of the dissolved ions, trace organic chemicals, and microorganisms in treated wastewater. (4) However, the ability of RO membranes to remove microorganisms and pathogens has been undervalued. For example, current RO membrane integrity monitoring methods are mostly based on the removal of surrogate substances: total organic carbon (TOC) and electrical conductivity. These surrogate indicators provide up to a 2 log reduction (i.e., 99% removal) for viruses and protozoa. (5) Bacterial water quality has also attracted much attention in DPR to minimize the risk of infection from enteric bacterial pathogens such as Salmonella spp. (3,5,6) For example, a 9 log reduction of total coliform bacteria through the treatment processes has been suggested for DPR. (7)
Considering RO membrane deterioration over time and unforeseen spikes of bacteria in raw sewage, the implementation of continuous monitoring of bacterial contaminants at low concentrations after RO treatment or in RO permeate will considerably enhance monitoring for bacterial contaminants in recycled water for water quality disruptions. For this purpose, the analytical instruments must be fast, reliable, sensitive, and accurate. Many commercial devices are capable of detecting bacteriological cells within a short analysis time (every 5 min to several hours). (8) Among them, flow cytometric bacterial cell counters combined with general nucleic acid staining make up an emerging technology capable of rapidly counting total bacterial cells. (9,10) In recent years, several near real-time or real-time bacteriological sensing technologies (e.g., BioSentry sensor) (11) have been evaluated for relatively clean waters, including drinking water. (12) Nevertheless, to date, real-time monitoring techniques have not been fully established with respect to potable reuse because of limitations with availability and adaptability in analyzing treated wastewater.
In this study, a real-time continuous bacterial counting technique that is capable of monitoring bacterial counts as low as one count per second in ultrapure water at a flow rate of 0.16 mL/s was evaluated with the RO feed and permeate of ultrafiltration (UF)-treated secondary wastewater. The real-time bacteriological counter can differentiate bacterial and nonbacterial particles using autofluorescence light emitted from riboflavin and nicotinamide adenine dinucleotide-hydrogen (NADH) and their scattered light. (13) This technique has the following advantages: speed, no additional chemicals, and sensitivity over other bacteriological monitoring technologies, including flow cytrometry, that has a range of approximately 20–100 cells/mL. (14,15) In addition to continuous online monitoring for bacteria, this technique, when applied to the RO feed and permeate, has a potential application in real-time membrane integrity monitoring. However, a significant challenge for real-time RO monitoring in the RO feed is interference by humic-like substances that can mask the detection of bacterial counts. (16) To enable online monitoring of the RO feed, a new strategy was adopted for the RO feed that was continuously diluted on line in real time.
This study aimed to evaluate the ability of real-time bacteriological counters to ensure that microbial contaminants are being removed by RO treatment. The study was performed by tracking the variation in bacterial counts in the RO feed and permeate at a pilot scale. The reduction in bacterial counts by RO treatment was confirmed by determining the total bacterial counts using epi-fluorescence microscopy.

Materials and Methods

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Analytical Techniques

Two real-time bacteriological counters (IMD-W, Azbil Corp., Tokyo, Japan) were used to monitor bacterial counts in the RO feed and RO permeate in real time. The real-time counter is capable of detecting the number of bacterial particles at 1 count/s by introducing part of the sample flow into the counter at a sampling flow rate of 0.16 mL/s. In other words, it can provide bacterial counts as low as 1 count/mL. The real-time bacteriological counter first exposes the running sample solution to the excitation light (wavelength of 405 nm), which primes the system to identify particles with scattered light (Figure S1). If the particle is a bacterium, intrinsic fluorescence emission is induced because of the autofluorescence property of riboflavin and NADH. The intensity of faint fluorescent light is received by two fluorescence detectors with different wavelength bands (wavelengths of approximately 415–450 and 490–530 nm) (Figure S1). Particles holding a certain level of autofluorescence light are recognized as bacteria and counted as biological particles. The real-time instrument counts all particles similar in size to bacteria in the sample and determines whether they are bacterial or nonbacterial particles. To confirm the real-time bacteriological counts, this study also analyzed total bacterial counts using a fluorescence microscope (Shibasaki, Inc., Chichibu, Japan) with 4′,6-diamidino-2-phenylindole (DAPI) dye (Text S1). Excitation emission matrix (EEM) fluorescence spectra were obtained using an Aqualog (Horiba, Kyoto, Japan). Details for the analytical conditions can be found elsewhere. (17)

Validation Protocol

A pilot-scale cross-flow RO filtration system comprised of a 4 in. spiral wound RO membrane element with the surface area of 7.43 m2 (ESPA2-LD-4040, Hydranautics/Nitto, Oceanside, CA) was used (Figure S2 and Text S2). The operation was performed by recirculating the RO permeate and concentrate into the feed reservoir and maintained at a permeate flux of 20 L m–2 h–1, a RO feed temperature of 14–16 °C, and a recovery of 20% (permeate and concentrate flow rates of 2.5 and 10 L/min, respectively). To stabilize the conditions of the process, the RO system was first operated using drinking water disinfected with chlorine (<5 mg/L) as the RO feed for 2 h. Thereafter, the RO feed was replaced with 50 L of ultrafiltration (UF)-treated wastewater, which was collected at a municipal wastewater treatment plant in Japan.
Bacterial counts in the RO permeate were determined by directly introducing the RO permeate into the real-time bacteriological counters (counter A) at a rate of 10 mL/min (Figure S2). In contrast, the RO feed sample (0.4 mL/min) was diluted 25-fold using a rate of 9.6 mL of purified water/min [i.e., microfiltration (MF)-treated RO permeate] prior to the entry into another real-time bacteriological counter (counter B). Online bacterial counts in the purified water were <2 counts/mL.

Results and Discussion

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Real-Time Bacteriological Monitoring

One challenge of the real-time bacteriological counter is counting bacterial particles in treated wastewater due to interference in a complex matrix. Treated wastewater likely contains humic acid-like substances as a source of fluorophores, which can be identified at excitation (Ex) and emission (Em) wavelengths of 350 and 425 nm, respectively, in the EEM spectrum. (18−20) In fact, in the UF-treated wastewater, a strong peak in the regions of the humic acid-like fluorophore, which was designated as A, was observed (Figure 1a). These humic acid-like substances in wastewater are too small (<1000 Da) to scatter the light, but they emit strong autofluorescence light that can exceed the light receiving capacity of fluorescence detectors and mask the detection of bacterial counts. (16) In this study, the regions of fluorescence detectors (Em wavelengths of approximately 415–450 and 490–530 nm) were overlapped with the fluorescence light of the UF-treated wastewater (Figure 1a). To reduce the impact of background interference in treated wastewater, this study employed an online 25-fold dilution method. After dilution with pure water, the humic-like substance- or other substance-derived autofluorescence in the matrix was substantially reduced (Figure 1b) and did not exceed the light receiving capacity of fluorescence detectors.

Figure 1

Figure 1. EEM fluorescence spectrum of UF-treated wastewater (a) without dilution and (b) with a 25-fold dilution.

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The potential of conductivity monitoring along with real-time bacteriological counting for RO membrane integrity testing was evaluated using the UF-treated wastewater at a pilot scale (Figure 2). Conductivity in the RO permeate remained stable throughout this test (Figure 2a). Over the course of 68 h pilot-scale testing, bacterial counts were determined in real time at approximately 1 × 103 to 4 × 104 counts/mL in the RO feed (UF-treated wastewater) and at approximately 4–342 counts/mL in the RO permeate (Figure 2b). During the first 4–6 h, online bacterial counts monitored in the RO feed and permeate decreased. The effect of change in the water matrix (i.e., from pure water to UF-treated wastewater) on online bacterial counts took approximately 2 h in both the RO feed and the RO permeate. This suggests that fair evaluations of the removal of bacteria by the RO membrane can be conducted only after operation for several hours, which is generally not an issue for full-scale long-term operation. From 6 to 36 h, a gradual increase in online bacterial counts in the RO feed was observed. The rapid increase from 36 to 45 h was likely due to biological growth (e.g., exponential phase) in the RO feed. However, the transmembrane pressure remained constant at 570–580 kPa, indicating that the biological growth did not increase the hydraulic resistance through the RO membrane. From 45 to 68 h, online bacterial counts in the RO feed decreased possibly because bacteria died after consuming nutrients or because of limited nutrients. Overall, bacterial rejection calculated by online bacterial counts was within the range of 98.32–99.98%, which was more variable than the range of conductivity rejection (i.e., 98.5–99.3%).

Figure 2

Figure 2. RO treatment of the UF-treated wastewater at a pilot scale: (a) conductivity, (b) online-monitored bacterial counts (plotted every 10 min), and (c) total bacterial counts (determined by epi-fluorescence). The RO feed temperature was maintained at 14–16 °C (Figure S3).

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The bacterial counts determined by the real-time bacteriological counter were confirmed by DAPI staining, which is routinely used as a nuclear counterstain in fluorescence microscopy and flow cytometry. (9) At eight manual sampling occasions during 68 h pilot-scale testing, total bacterial counts determined by epi-fluorescence microscopy were determined at 3.5 × 104 to 2.0 × 105 and 5.0 × 102 to 1.3 × 103 counts/mL in the RO feed (UF-treated wastewater) and permeate, respectively (Figure 2c). A high correlation (R2 = 0.83) was identified between the online bacterial counts and epi-fluorescence counts in the RO feed; a negligible correlation (R2 = 0.14) was observed for the RO permeate (Figure 3). For the RO feed, a higher correlation (R2 = 0.99) was observed until the seven manual sampling occasions were reached (i.e., until 50 h) while bacterial counts increased rapidly. Likewise, for the RO permeate, a higher correlation was obtained when counting was performed during earlier sampling occasions. Although a high correlation was not obtained for the RO permeate, the reduction in bacterial counts by RO treatment was confirmed by both online bacterial counts and epi-fluorescence microscopy.

Figure 3

Figure 3. Total bacterial count (determined by epi-fluorescence) as a function of online bacterial count during RO treatment of the UF-treated wastewater.

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With regard to absolute bacterial counts, the total bacterial counts (determined by epi-fluorescence), which include both dead and live bacteria, were greater than the online bacterial counts (Figure 3). This is likely due to the differences in the detection mechanisms of the two techniques. In theory, total bacterial counts as determined by DAPI are the sum of dead and live cells and less dependent on viability due to the nature of the assay. In contrast, the real-time bacteriological counter does not differentiate between dead or live bacteria; however, dead or stressed (i.e., injured) bacterial cells that emit less autofluorescence are less likely to be counted. The detection of bacteria by the real-time bacteriological counters is influenced by the bacterial concentration and the state of the bacterial cells (i.e., starved/stressed cells that are smaller or cells that tend to clump and exist in clusters) in treated wastewater. Bacterial cells can adhere to pilot plant materials, including RO membrane surfaces and biofilms on RO membranes. (21) The aggregation of bacterial cells in the stream can also cause underestimation of bacterial counts because the aggregated bacterial cells will be recognized as one large bacterial size particle. One common limitation of bacterial counting that can be applied to heterotrophic plate counts, microscopy, and flow cytometry, is cell aggregation or clumping, in which several clumped cells are underestimated as a single cell or colony forming unit. (22) Because of this limitation, automated cell counting methods, including flow cytometry, have incorporated pretreatment steps such as ultrasonication to disperse and suspend bacterial cells prior to counting. (21) Moreover, bacteria propagate and die, resulting in large variations in their detection by continuous real-time monitoring, particularly during recirculation of the RO feed. For further validation, other counting methods similar to real-time bacteriological monitoring or other standard methods such as growth-based assays on a culture medium (e.g., R2A agar) should be applied.

Passage of Bacteria through the RO Membrane

The question of how bacterial cells pass through the RO membrane element remains. Although the size of a bacterium (typically >200 nm) is theoretically greater than the pore size (or free-volume hole size) of the RO membrane (<1 nm), (23) a number of bacterial cells passed through the RO membrane element in this study. This is consistent with previous studies reporting incomplete removal of bacteria by spiral wound style nanofiltration and RO membrane elements. (15,24−27) Although the RO membrane itself is a very tight membrane, passage of bacterial cells is possible through interconnectors of RO membrane elements fitted with O-ring seals. (24,28,29) These interconnectors separate the RO feed (high-pressure stream) and RO permeate (low-pressure stream in the RO permeate tube) with only one O-ring for each connection (Figure S4); thus, a small amount of bacteria could pass from the RO feed to the RO permeate. The cause of the bacterial passage to the RO permeate is not fully understood at present; this will be the scope of our future study. Despite our better understanding of the mechanism, this study provides a motivation for improving the tightness of RO membrane elements for greater bacterial removal.

Implications for On-Site Use

This study demonstrates the real-time online monitoring of bacterial counts in the RO feed and permeate. Real-time bacterial monitoring provided an online profile of bacterial counts to ensure continuous removal of bacterial contaminants by RO treatment. Further evaluations using wastewaters with different water matrices and bacterial concentrations are necessary to determine the versatility of online monitoring. As described in this study, this real-time bacteriological counting technology has three advantages over the other techniques: (a) Real-time bacteriological counters measure biomarkers produced by all bacteria using optical techniques, which differs from the conventional method for measuring a single indicator microorganism such as Escherichia coli; (b) It measures both biological and nonbiological particles and can differentiate between them; (c) It can measure bacterial cells at very low concentrations in real time.
Additionally, there are three other potential benefits of water treatment process control: (a) Online bacterial counts can function as process control indicators of treatment efficacy; (b) The real-time bacteriological counter has the ability to detect incremental failure of RO treatment; (c) The real-time bacteriological counter can be used at the back end of RO treatment to validate the decrease in bacterial concentration or to continuously validate nondetection of bacterial counts.

Supporting Information

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The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.estlett.8b00200.

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Author Information

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  • Corresponding Author
  • Authors
    • Anh T. Hoang - Water and Environmental Engineering, Graduate School of Engineering, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
    • Hidenobu Aizawa - Environment Management Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan
    • Hiroki Ashiba - Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
    • Makoto Fujimaki - Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
    • Menu Leddy - Orange County Water District, 18700 Ward Street, Fountain Valley, California 92708, United States
  • Notes
    The authors declare no competing financial interest.

Acknowledgments

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The authors acknowledge Hydranautics for providing RO membrane elements. The authors also acknowledge Azbil Corp. for providing real-time bacteriological monitors.

References

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This article references 29 other publications.

  1. 1
    Burgess, J.; Meeker, M.; Minton, J.; O’Donohue, M. International research agency perspectives on potable water reuse. Environ. Sci.: Water Res. Technol. 2015, 1 (5), 563– 580,  DOI: 10.1039/C5EW00165J
    Google Scholar
    There is no corresponding record for this reference.
  2. 2
    Harris-Lovett, S. R.; Binz, C.; Sedlak, D. L.; Kiparsky, M.; Truffer, B. Beyond User Acceptance: A Legitimacy Framework for Potable Water Reuse in California. Environ. Sci. Technol. 2015, 49 (13), 7552– 7561,  DOI: 10.1021/acs.est.5b00504
    Google Scholar
    2
    Beyond User Acceptance: A Legitimacy Framework for Potable Water Reuse in California
    Harris-Lovett, Sasha R.; Binz, Christian; Sedlak, David L.; Kiparsky, Michael; Truffer, Bernhard
    Environmental Science & Technology (2015), 49 (13), 7552-7561CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)
    Water resource managers often tout the potential of potable water reuse to provide a reliable, local source of drinking water in water-scarce regions. Despite data documenting the ability of advanced treatment technologies to treat municipal wastewater effluent to meet existing drinking water quality stds., many utilities face skepticism from the public about potable water reuse. Prior research on this topic has mainly focused on marketing strategies for garnering public acceptance of the process. This study takes a broader perspective on the adoption of potable water reuse based on concepts of societal legitimacy, which is the generalized perception or assumption that a technol. is desirable or appropriate within its social context. To assess why some potable reuse projects were successfully implemented while others faced fierce public opposition, we performed a series of 20 expert interviews and reviewed in-depth case studies from potable reuse projects in California. Results show that proponents of a legitimated potable water reuse project in Orange County, California engaged in a portfolio of strategies that addressed 3 main dimensions of legitimacy. In contrast, other proposed projects that faced extensive public opposition relied on a smaller set of legitimation strategies that focused near-exclusively on the development of robust water treatment technol. Widespread legitimation of potable water reuse projects, including direct potable water reuse, may require the establishment of a portfolio of stds., procedures, and possibly new institutions.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXpsVSrs7g%253D&md5=0e5c2f5dfcb83be1074691de5a765627
  3. 3
    Mosher, J. J.; Vartanian, G. M.; Tchobanoglous, G. Potable reuse research compilation: Synthesis of findings; National Water Research Institute and Water Environment & Reuse Foundation: Fountain Valley, CA, 2016.
    Google Scholar
    There is no corresponding record for this reference.
  4. 4
    Henderson, R. K.; Baker, A.; Murphy, K. R.; Hambly, A.; Stuetz, R. M.; Khan, S. J. Fluorescence as a potential monitoring tool for recycled water systems: A review. Water Res. 2009, 43 (4), 863– 881,  DOI: 10.1016/j.watres.2008.11.027
    Google Scholar
    4
    Fluorescence as a potential monitoring tool for recycled water systems: A review
    Henderson, R. K.; Baker, A.; Murphy, K. R.; Hambly, A.; Stuetz, R. M.; Khan, S. J.
    Water Research (2009), 43 (4), 863-881CODEN: WATRAG; ISSN:0043-1354. (Elsevier Ltd.)
    A review. A rapid, highly sensitive and selective detector is urgently required to detect contamination events in recycled water systems, for example, cross-connection events in dual reticulation pipes that recycle advanced treated sewage effluent, as existing technologies, including total org. carbon and cond. monitoring, cannot always provide the sensitivity required. Fluorescence spectroscopy has been suggested as a potential monitoring tool given its high sensitivity and selectivity. A review of recent literature demonstrates that by monitoring the fluorescence of dissolved org. matter (DOM), the ratios of humic-like (Peak C) and protein-like (Peak T) fluorescence peaks can be used to identify trace sewage contamination in river waters and estuaries, a situation analogous to contamination detection in recycled water systems. Addnl., strong correlations have been shown between Peak T and BOD in rivers, which is indicative of water impacted by microbial activity and therefore of sewage impacted systems. Hence, this review concludes that the sensitive detection of contamination events in recycled water systems may be achieved by monitoring Peak T and/or Peak C fluorescence. However, in such systems, effluent is treated to a high std. resulting in much lower DOM concns. and the impact of these advanced treatment processes on Peaks T and C fluorescence is largely unknown and requires investigation. This review has highlighted that further work is also required to det. (a) the stability and distinctiveness of recycled water fluorescence in relation to the treatment processes utilized, (b) the impact of matrix effects, particularly the impact of oxidn., (c) calibration issues for online monitoring, and (d) the advanced data anal. techniques required, if any, to improve detection of contamination events.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXisVGjtLo%253D&md5=421313a3a89b1a5d1769d4c7a38ea75c
  5. 5
    Tchobanoglous, G.; Cotruvo, J.; Crook, J.; McDonald, E.; Olivieri, A.; Salveson, A.; Trussell, R. S. Framework for direct potable reuse; WateReuse Association, American Water Works Association, Water Environment Federation, National Water Research Institute: Alexandria, VA, 2015.
    Google Scholar
    There is no corresponding record for this reference.
  6. 6
    Potable reuse: guidance for producing safe drinking-water; World Health Organization: Geneva, 2017.
    Google Scholar
    There is no corresponding record for this reference.
  7. 7
    Examining the Criteria for Direct Potable Reuse. WateReuse Research Foundation Project 11-02; National Water Research Institute: Fountain Valley, CA, 2013.
    Google Scholar
    There is no corresponding record for this reference.
  8. 8
    Lopez-Roldan, R.; Tusell, P.; Cortina, J. L.; Courtois, S.; Cortina, J. L. On-line bacteriological detection in water. TrAC, Trends Anal. Chem. 2013, 44, 46– 57,  DOI: 10.1016/j.trac.2012.10.010
    Google Scholar
    8
    On-line bacteriological detection in water
    Lopez-Roldan, Ramon; Tusell, Pol; Cortina, Jose Luis; Courtois, Sophie
    TrAC, Trends in Analytical Chemistry (2013), 44 (), 46-57CODEN: TTAEDJ; ISSN:0165-9936. (Elsevier B. V.)
    A review. Microorganism contamination is a permanent concern in a wide range of fields, including the water-treatment, food and pharmaceutical industries, in which fast detection is crit. to prevent microbial outbreaks. In water monitoring, current procedures for water-quality anal. are based on periodic sampling and detection by culture methods, which are slow, requiring 24-48 h for completion, so that, when first results reach the decision-takers and trigger an alarm, significant time has already passed and the population may have been exposed to a health hazard. There is a need for rapid, reliable detection of contaminants in a broad spectrum of water-management situations. For real-time detection, online monitoring seems to be the ideal approach, but the need to adjust the available techniques to autonomous operation and the optimization of response time are substantial challenges. This review presents the findings of an identification study about the state-of-the-art of technologies and com. devices for online biomonitoring of water quality, specifically for the detection of fecal contamination. We also include studies dealing with verification or use of these devices.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXktFWqu74%253D&md5=3aeb7cd8994db5c9f11c3aba18380bde
  9. 9
    Van Nevel, S.; Koetzsch, S.; Proctor, C. R.; Besmer, M. D.; Prest, E. I.; Vrouwenvelder, J. S.; Knezev, A.; Boon, N.; Hammes, F. Flow cytometric bacterial cell counts challenge conventional heterotrophic plate counts for routine microbiological drinking water monitoring. Water Res. 2017, 113, 191– 206,  DOI: 10.1016/j.watres.2017.01.065
    Google Scholar
    9
    Flow cytometric bacterial cell counts challenge conventional heterotrophic plate counts for routine microbiological drinking water monitoring
    Van Nevel, S.; Koetzsch, S.; Proctor, C. R.; Besmer, M. D.; Prest, E. I.; Vrouwenvelder, J. S.; Knezev, A.; Boon, N.; Hammes, F.
    Water Research (2017), 113 (), 191-206CODEN: WATRAG; ISSN:0043-1354. (Elsevier Ltd.)
    A review with many refs. Drinking water utilities and researchers continue to rely on the century-old heterotrophic plate counts (HPC) method for routine assessment of general microbiol. water quality. Bacterial cell counting with flow cytometry (FCM) is one of a no. of alternative methods that challenge this status quo and provide an opportunity for improved water quality monitoring. After more than a decade of application in drinking water research, FCM methodol. is optimized and established for routine application, supported by a considerable amt. of data from multiple full-scale studies. Bacterial cell concns. obtained by FCM enable quantification of the entire bacterial community instead of the minute fraction of cultivable bacteria detected with HPC (typically < 1% of all bacteria). FCM measurements are reproducible with relative std. deviations below 3% and can be available within 15 min of samples arriving in the lab. High throughput sample processing and complete automation are feasible and FCM anal. is arguably less expensive than HPC when measuring more than 15 water samples per day, depending on the lab. and selected staining procedure(s). Moreover, many studies have shown FCM total (TCC) and intact (ICC) cell concns. to be reliable and robust process variables, responsive to changes in the bacterial abundance and relevant for characterizing and monitoring drinking water treatment and distribution systems. The purpose of this crit. review is to initiate a constructive discussion on whether FCM could replace HPC in routine water quality monitoring. We argue that FCM provides a faster, more descriptive and more representative quantification of bacterial abundance in drinking water.
    >> More from SciFinder ®
    https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXivFWksLk%253D&md5=ceef2c8759cac828271b3eabd0a5f4d8
  10. 10
    Prest, E. I.; Hammes, F.; Kötzsch, S.; van Loosdrecht, M. C. M.; Vrouwenvelder, J. S. Monitoring microbiological changes in drinking water systems using a fast and reproducible flow cytometric method. Water Res. 2013, 47 (19), 7131– 7142,  DOI: 10.1016/j.watres.2013.07.051
    Google Scholar
    10
    Monitoring microbiological changes in drinking water systems using a fast and reproducible flow cytometric method
    Prest, E. I.; Hammes, F.; Koetzsch, S.; van Loosdrecht, M. C. M.; Vrouwenvelder, J. S.
    Water Research (2013), 47 (19), 7131-7142CODEN: WATRAG; ISSN:0043-1354. (Elsevier Ltd.)
    Flow cytometry (FCM) is a rapid, cultivation-independent tool to assess and evaluate bacteriol. quality and biol. stability of water. Here we demonstrate that a stringent, reproducible staining protocol combined with fixed FCM operational and gating settings is essential for reliable quantification of bacteria and detection of changes in aquatic bacterial communities. Triplicate measurements of diverse water samples with this protocol typically showed relative std. deviation values and 95% confidence interval values below 2.5% on all the main FCM parameters. We propose a straightforward and instrument-independent method for the characterization of water samples based on the combination of bacterial cell concn. and fluorescence distribution. Anal. of the fluorescence distribution (or so-called fluorescence fingerprint) was accomplished firstly through a direct comparison of the raw FCM data and subsequently simplified by quantifying the percentage of large and brightly fluorescent high nucleic acid (HNA) content bacteria in each sample. Our approach enables fast differentiation of dissimilar bacterial communities (less than 15 min from sampling to final result), and allows accurate detection of even small changes in aquatic environments (detection above 3% change). Demonstrative studies on (a) indigenous bacterial growth in water, (b) contamination of drinking water with wastewater, (c) household drinking water stagnation and (d) mixing of two drinking water types, univocally showed that this FCM approach enables detection and quantification of relevant bacterial water quality changes with high sensitivity. This approach has the potential to be used as a new tool for application in the drinking water field, e.g. for rapid screening of the microbial water quality and stability during water treatment and distribution in networks and premise plumbing.
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  11. 11
    Sherchan, S. P.; Gerba, C. P.; Pepper, I. L. Evaluation of Real-Time Water Quality Sensors for the Detection of Intentional Bacterial Spore Contamination of Potable Water. J. Biosens. Bioelectron. 2013, 4 (4), 1– 5,  DOI: 10.4172/2155-6210.1000141
    Google Scholar
    There is no corresponding record for this reference.
  12. 12
    Miles, S. L.; Sinclair, R. G.; Riley, M. R.; Pepper, I. L. Evaluation of Select Sensors for Real-Time Monitoring of Escherichia coli in Water Distribution Systems. Appl. Environ. Microbiol. 2011, 77 (8), 2813– 2816,  DOI: 10.1128/AEM.02618-10
    Google Scholar
    There is no corresponding record for this reference.
  13. 13
    Ammor, M. S. Recent Advances in the Use of Intrinsic Fluorescence for Bacterial Identification and Characterization. J. Fluoresc. 2007, 17 (5), 455– 459,  DOI: 10.1007/s10895-007-0180-6
    Google Scholar
    13
    Recent advances in the use of intrinsic fluorescence for bacterial identification and characterization
    Ammor, Mohammed Salim
    Journal of Fluorescence (2007), 17 (5), 455-459CODEN: JOFLEN; ISSN:1053-0509. (Springer)
    A review. Live bacteria contain a variety of intracellular biomols. that have specific excitation and emission wavelength spectra characterizing their intrinsic fluorescence. This paper reviews recent developed methods using bacterial intrinsic fluorescence for identification and characterization purposes. Potential applications of such methods at the industrial level are also addressed.
    >> More from SciFinder ®
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  14. 14
    Huang, X.; Zhao, Z.; Hernandez, D.; Jiang, S. Near Real-Time Flow Cytometry Monitoring of Bacterial and Viral Removal Efficiencies during Water Reclamation Processes. Water 2016, 8 (10), 464,  DOI: 10.3390/w8100464
    Google Scholar
    There is no corresponding record for this reference.
  15. 15
    Miller, S. E.; Nelson, K. L.; Rodriguez, R. A. Microbiological Stability in Direct Potable Reuse Systems: Insights from Pilot-Scale Research Using Flow Cytometry and High-Throughput Sequencing. Proceedings of the Water Environment Federation 2017, 2017 (14), 1016– 1023,  DOI: 10.2175/193864717822153779
    Google Scholar
    There is no corresponding record for this reference.
  16. 16
    Pepper, I. L.; Snyder, S. A. Monitoring for reliability and process control of potable reuse applications; Water Environment & Reuse Foundation and IWA Publishing: Alexandria, VA, 2016.
    Google Scholar
    There is no corresponding record for this reference.
  17. 17
    Fujioka, T.; Kodamatani, H.; Aizawa, H.; Gray, S.; Ishida, K. P.; Nghiem, L. D. Role of membrane fouling substances on the rejection of N-nitrosamines by reverse osmosis. Water Res. 2017, 118, 187– 195,  DOI: 10.1016/j.watres.2017.03.057
    Google Scholar
    There is no corresponding record for this reference.
  18. 18
    Liu, T.; Chen, Z.-l.; Yu, W.-z.; You, S.-j. Characterization of organic membrane foulants in a submerged membrane bioreactor with pre-ozonation using three-dimensional excitation–emission matrix fluorescence spectroscopy. Water Res. 2011, 45 (5), 2111– 2121,  DOI: 10.1016/j.watres.2010.12.023
    Google Scholar
    18
    Characterization of organic membrane foulants in a submerged membrane bioreactor with pre-ozonation using three-dimensional excitation-emission matrix fluorescence spectroscopy
    Liu, Ting; Chen, Zhong-lin; Yu, Wen-zheng; You, Shi-jie
    Water Research (2011), 45 (5), 2111-2121CODEN: WATRAG; ISSN:0043-1354. (Elsevier B.V.)
    This study focuses on org. membrane foulants in a submerged membrane bioreactor (MBR) process with pre-ozonation compared to an individual MBR using three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy. While the influent was continuously ozonated at a normal dosage, preferable org. matter removal was achieved in subsequent MBR, and trans-membrane pressure increased at a much lower rate than that of the individual MBR. EEM fluorescence spectroscopy was employed to characterize the dissolved org. matter (DOM) samples, extracellular polymeric substance (EPS) samples and membrane foulants. Four main peaks could be identified from the EEM fluorescence spectra of the DOM samples in both MBRs. Two peaks were assocd. with the protein-like fluorophores, and the other ones were related to the humic-like fluorophores. The results indicated that pre-ozonation decreased fluorescence intensities of all peaks in the EEM spectra of influent DOM esp. for protein-like substances and caused red shifts of all fluorescence peaks to different extents. The peak intensities of the protein-like substances represented by Peak T1 and T2 in EPS spectra were obviously decreased as a result of pre-ozonation. Both external and internal fouling could be effectively mitigated by the pre-ozonation. The most primary component of external foulants was humic acid-like substance (Peak C) in the MBR with pre-ozonation and protein-like substance (Peak T1) in the individual MBR, resp. The content decrease of protein-like substances and structural change of humic-like substances were obsd. in external foulants from EEM fluorescence spectra due to pre-ozonation. However, it could be seen that ozonation resulted in significant redn. of intensities but little location shift of all peaks in EEM fluorescence spectra of internal foulants.
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  19. 19
    Nam, S.-N.; Amy, G. Differentiation of wastewater effluent organic matter (EfOM) from natural organic matter (NOM) using multiple analytical techniques. Water Sci. Technol. 2008, 57 (7), 1009– 1015,  DOI: 10.2166/wst.2008.165
    Google Scholar
    19
    Differentiation of wastewater effluent organic matter (EfOM) from natural organic matter (NOM) using multiple analytical techniques
    Nam, Seong-Nam; Amy, Gary
    Water Science and Technology (2008), 57 (7), 1009-1015CODEN: WSTED4; ISSN:0273-1223. (IWA Publishing)
    Using three anal. techniques of size exclusion chromatog. (SEC), fluorescence excitation-emission matrix (EEM), and dissolved org. nitrogen (DON) measurement, differentiating characteristics of effluent org. matter (EfOM) from natural org. matter (NOM) have been investigated. SEC reveals a wide range of mol. wt. (MW) for EfOM and high amt. of high MW polysaccharides, and low MW org. acids compared to NOM. Clear protein-like peaks using fluorescence EEM were a major feature of EfOM distinguishing it from NOM. Fluorescence index (FI), an indicator to distinguish autochthonous origin from allochthonous origin, differentiated EfOM from NOM by exhibiting higher values, indicating a microbial origin. In EfOM samples, DON present in higher amts. than NOM.
    >> More from SciFinder ®
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  20. 20
    Chen, W.; Westerhoff, P.; Leenheer, J. A.; Booksh, K. Fluorescence excitation–emission matrix regional integration to quantify spectra for dissolved organic matter. Environ. Sci. Technol. 2003, 37 (24), 5701– 5710,  DOI: 10.1021/es034354c
    Google Scholar
    20
    Fluorescence Excitation-Emission Matrix Regional Integration to Quantify Spectra for Dissolved Organic Matter
    Chen, Wen; Westerhoff, Paul; Leenheer, Jerry A.; Booksh, Karl
    Environmental Science and Technology (2003), 37 (24), 5701-5710CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)
    Excitation-emission matrix (EEM) fluorescence spectroscopy has been widely used to characterize dissolved org. matter (DOM) in water and soil. However, interpreting the >10,000 wavelength-dependent fluorescence intensity data points represented in EEMs has posed a significant challenge. Fluorescence regional integration, a quant. technique that integrates the vol. beneath an EEM, was developed to analyze EEMs. EEMs were delineated into five excitation-emission regions based on the fluorescence of model compds., DOM fractions, and marine waters or fresh waters. Volumetric integration under the EEM within each region, normalized to the projected excitation-emission area within that region and dissolved org. carbon concn., resulted in a normalized region-specific EEM vol. (Φi,n). Solid-state carbon NMR (13C NMR), Fourier transform IR (FTIR) anal., UV-visible absorption spectra, and EEMs were obtained for std. Suwannee River fulvic acid and 15 hydrophobic or hydrophilic acid, neutral, and base DOM fractions plus nonfractionated DOM from wastewater effluents and rivers in the southwestern USA. DOM fractions fluoresced in one or more EEM regions. The highest cumulative EEM vol. (ΦT,n = ΣΦi,n) was obsd. for hydrophobic neutral DOM fractions, followed by lower ΦT,n values for hydrophobic acid, base, and hydrophilic acid DOM fractions, resp. An extd. wastewater biomass DOM sample contained arom. protein- and humic-like material and was characteristic of bacterial sol. microbial products. Arom. carbon and the presence of specific arom. compds. (as indicated by solid-state 13C NMR and FTIR data) resulted in EEMs that aided in differentiating wastewater effluent DOM from drinking water DOM.
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  21. 21
    Prest, E. I.; Hammes, F.; van Loosdrecht, M. C. M.; Vrouwenvelder, J. S. Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges. Front. Microbiol. 2016, 7 (45), 1– 24,  DOI: 10.3389/fmicb.2016.00045
    Google Scholar
    There is no corresponding record for this reference.
  22. 22
    Ou, F.; McGoverin, C.; Swift, S.; Vanholsbeeck, F. Absolute bacterial cell enumeration using flow cytometry. J. Appl. Microbiol. 2017, 123 (2), 464– 477,  DOI: 10.1111/jam.13508
    Google Scholar
    22
    Absolute bacterial cell enumeration using flow cytometry
    Ou, F.; McGoverin, C.; Swift, S.; Vanholsbeeck, F.
    Journal of Applied Microbiology (2017), 123 (2), 464-477CODEN: JAMIFK; ISSN:1364-5072. (Wiley-Blackwell)
    Aim : To evaluate a flow cytometry protocol that uses ref. beads for the enumeration of live and dead bacteria present in a mixt. Methods and Results : Mixts. of live and dead Escherichia coli with live:dead concn. ratios varying from 0 to 100% were prepd. These samples were stained using SYTO 9 and propidium iodide and 6-μm ref. beads were added. Bacteria present in live samples were enumerated by agar plate counting. Bacteria present in dead samples were enumerated by agar plate counting before treatment with isopropanol. There is a linear relationship between the presented flow cytometry method and agar plate counts for live (R2 = 0·99) and dead E. coli (R2 = 0·93) concns. of c. 104 to 108 bacteria per mL within mixts. of live and dead bacteria. Conclusions : Reliable enumeration of live E. coli within a mixt. of both live and dead was possible for concn. ratios of above 2·5% live and for the enumeration of dead E. coli the lower limit was c. 20% dead. Significance and Impact of the Study : The ability to obtain abs. cell concns. is only available for selected flow cytometers, this study describes a method for accurate enumeration that is applicable to basic flow cytometers without specialized counting features. By demonstrating the application of the method to count E. coli, we raised points of consideration for using this FCM counting method and aim to lay the foundation for future work that uses similar methods for different bacterial strains.
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  23. 23
    Fujioka, T.; Oshima, N.; Suzuki, R.; Khan, S. J.; Roux, A.; Poussade, Y.; Drewes, J. E.; Nghiem, L. D. Rejection of small and uncharged chemicals of emerging concern by reverse osmosis membranes: The role of free volume space within the active skin layer. Sep. Purif. Technol. 2013, 116, 426– 432,  DOI: 10.1016/j.seppur.2013.06.015
    Google Scholar
    23
    Rejection of small and uncharged chemicals of emerging concern by reverse osmosis membranes: The role of free volume space within the active skin layer
    Fujioka, Takahiro; Oshima, Nagayasu; Suzuki, Ryoichi; Khan, Stuart J.; Roux, Annalie; Poussade, Yvan; Drewes, Jorg E.; Nghiem, Long D.
    Separation and Purification Technology (2013), 116 (), 426-432CODEN: SPUTFP; ISSN:1383-5866. (Elsevier B.V.)
    Free-vol. hole-radii of the active skin layer of one seawater and 2 low pressure reverse osmosis (RO) membranes, namely SWC5, ESPAB, and ESPA2, resp., were evaluated using positron annihilation lifetime spectroscopy (PALS) with a slow positron beam. The results were related to the rejection of boric acid and eight N-nitrosamines to provide insights to the transport of these small solutes through RO membranes. At pH 8 (which is the exptl. pH in this study), these solutes are uncharged. PALS anal. showed that the SWC5 has the smallest mean free-vol. hole-radius (0.259 nm) among the three RO membranes studied. Correspondingly, the SWC5 membrane exhibited the highest rejection of boric acid and all N-nitrosamines. Results reported here also showed that the rejection of these chems. increased in the order of increasing mol. vol. The difference in their rejection amongst the 3 RO membranes studied was most apparent for those (i.e., boric acid and N-nitrosodimethylamine (NDMA)) with a small mol. vol. The EPSA2 and ESPAB were detd. to have mean free-vol. hole-radius of 0.289 nm. However, the ESPAB membrane had lower water permeability and showed considerably higher rejection of boric acid and NDMA than the ESPA2 membrane. These results suggest that in addn. to the mean free-vol. hole-radius, other membrane parameters and properties such as the free-vol. hole-radius distribution and thickness of the active skin layer can also play a role in governing the rejection of small and uncharged solutes by RO membranes.
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  24. 24
    Park, S.; Hu, J. Y. Assessment of the extent of bacterial growth in reverse osmosis system for improving drinking water quality. J. Environ. Sci. Health, Part A: Toxic/Hazard. Subst. Environ. Eng. 2010, 45 (8), 968– 977,  DOI: 10.1080/10934521003772386
    Google Scholar
    There is no corresponding record for this reference.
  25. 25
    Ishida, K. P.; Cooper, W. J. Analysis of parameters affecting process efficiency, energy consumption, and carbon footprint in water reuse; WateReuse Research Foundation: Alexandria, VA, 2015.
    Google Scholar
    There is no corresponding record for this reference.
  26. 26
    Liikanen, R.; Miettinen, I.; Laukkanen, R. Selection of NF membrane to improve quality of chemically treated surface water. Water Res. 2003, 37 (4), 864– 872,  DOI: 10.1016/S0043-1354(02)00412-8
    Google Scholar
    There is no corresponding record for this reference.
  27. 27
    Laurent, P.; Servais, P.; Gatel, D.; Randon, G.; Bonne, P.; Cavard, J. Microbiological quality: Before and after nanofiltration. J. - Am. Water Works Assoc. 1999, 91 (10), 62– 72,  DOI: 10.1002/j.1551-8833.1999.tb08716.x
    Google Scholar
    27
    Microbiological quality before and after nanofiltration
    Laurent, Patrick; Servais, Pierre; Gatel, Dominique; Randon, Guy; Bonne, Pascal; Cavard, Jacques
    Journal - American Water Works Association (1999), 91 (10), 62-72CODEN: JAWWA5; ISSN:0003-150X. (American Water Works Association)
    The authors investigated microbiol. behavior of a distribution system supplied initially with biol. treated water and then with nanofiltered water. Their purpose was to identify and evaluate the changes in microbiol. water quality attributable to modifications in water treatment at the plant. During the course of the study, all data from various indicators of microbiol. quality (i.e., heterotrophic plate counts, coliform enumeration, total direct counts, and fixed bacterial biomass) showed similar trends. Results indicated that the use of nanofiltration allows utilities to reduce chlorination of treated water and at least maintain or increase the microbiol. quality of distributed water for areas with high residence times.
    >> More from SciFinder ®
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  28. 28
    Pype, M.-L.; Lawrence, M. G.; Keller, J.; Gernjak, W. Reverse osmosis integrity monitoring in water reuse: The challenge to verify virus removal – A review. Water Res. 2016, 98, 384– 395,  DOI: 10.1016/j.watres.2016.04.040
    Google Scholar
    28
    Reverse osmosis integrity monitoring in water reuse: The challenge to verify virus removal - A review
    Pype, Marie-Laure; Lawrence, Michael G.; Keller, Jurg; Gernjak, Wolfgang
    Water Research (2016), 98 (), 384-395CODEN: WATRAG; ISSN:0043-1354. (Elsevier Ltd.)
    A review with many refs. A reverse osmosis (RO) process is often included in the treatment train to produce high quality reuse water from treated effluent for potable purposes because of its high removal efficiency for salinity and many inorg. and org. contaminants, and importantly, it also provides an excellent barrier for pathogens. In order to ensure the continued protection of public health from pathogen contamination, monitoring RO process integrity is necessary. Due to their small sizes, viruses are the most difficult class of pathogens to be removed in phys. sepn. processes and therefore often considered the most challenging pathogen to monitor. To-date, there is a gap between the current log credit assigned to this process (detd. by integrity testing approved by regulators) and its actual log removal capability as proven in a variety of lab. and pilot studies. Hence, there is a challenge to establish a methodol. that more closely links to the theor. performance. In this review, after introducing the notion of risk management in water reuse, we provide an overview of existing and potentially new RO integrity monitoring techniques, highlight their strengths and drawbacks, and debate their applicability to full-scale treatment plants, which open to future research opportunities.
    >> More from SciFinder ®
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  29. 29
    Liu, G.; Lut, M. C.; Verberk, J. Q. J. C.; Van Dijk, J. C. A comparison of additional treatment processes to limit particle accumulation and microbial growth during drinking water distribution. Water Res. 2013, 47 (8), 2719– 2728,  DOI: 10.1016/j.watres.2013.02.035
    Google Scholar
    There is no corresponding record for this reference.

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    Figure 1

    Figure 1. EEM fluorescence spectrum of UF-treated wastewater (a) without dilution and (b) with a 25-fold dilution.

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    Figure 2

    Figure 2. RO treatment of the UF-treated wastewater at a pilot scale: (a) conductivity, (b) online-monitored bacterial counts (plotted every 10 min), and (c) total bacterial counts (determined by epi-fluorescence). The RO feed temperature was maintained at 14–16 °C (Figure S3).

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    Figure 3

    Figure 3. Total bacterial count (determined by epi-fluorescence) as a function of online bacterial count during RO treatment of the UF-treated wastewater.

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    This article references 29 other publications.

    1. 1
      Burgess, J.; Meeker, M.; Minton, J.; O’Donohue, M. International research agency perspectives on potable water reuse. Environ. Sci.: Water Res. Technol. 2015, 1 (5), 563– 580,  DOI: 10.1039/C5EW00165J
      Google Scholar
      There is no corresponding record for this reference.
    2. 2
      Harris-Lovett, S. R.; Binz, C.; Sedlak, D. L.; Kiparsky, M.; Truffer, B. Beyond User Acceptance: A Legitimacy Framework for Potable Water Reuse in California. Environ. Sci. Technol. 2015, 49 (13), 7552– 7561,  DOI: 10.1021/acs.est.5b00504
      Google Scholar
      2
      Beyond User Acceptance: A Legitimacy Framework for Potable Water Reuse in California
      Harris-Lovett, Sasha R.; Binz, Christian; Sedlak, David L.; Kiparsky, Michael; Truffer, Bernhard
      Environmental Science & Technology (2015), 49 (13), 7552-7561CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)
      Water resource managers often tout the potential of potable water reuse to provide a reliable, local source of drinking water in water-scarce regions. Despite data documenting the ability of advanced treatment technologies to treat municipal wastewater effluent to meet existing drinking water quality stds., many utilities face skepticism from the public about potable water reuse. Prior research on this topic has mainly focused on marketing strategies for garnering public acceptance of the process. This study takes a broader perspective on the adoption of potable water reuse based on concepts of societal legitimacy, which is the generalized perception or assumption that a technol. is desirable or appropriate within its social context. To assess why some potable reuse projects were successfully implemented while others faced fierce public opposition, we performed a series of 20 expert interviews and reviewed in-depth case studies from potable reuse projects in California. Results show that proponents of a legitimated potable water reuse project in Orange County, California engaged in a portfolio of strategies that addressed 3 main dimensions of legitimacy. In contrast, other proposed projects that faced extensive public opposition relied on a smaller set of legitimation strategies that focused near-exclusively on the development of robust water treatment technol. Widespread legitimation of potable water reuse projects, including direct potable water reuse, may require the establishment of a portfolio of stds., procedures, and possibly new institutions.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXpsVSrs7g%253D&md5=0e5c2f5dfcb83be1074691de5a765627
    3. 3
      Mosher, J. J.; Vartanian, G. M.; Tchobanoglous, G. Potable reuse research compilation: Synthesis of findings; National Water Research Institute and Water Environment & Reuse Foundation: Fountain Valley, CA, 2016.
      Google Scholar
      There is no corresponding record for this reference.
    4. 4
      Henderson, R. K.; Baker, A.; Murphy, K. R.; Hambly, A.; Stuetz, R. M.; Khan, S. J. Fluorescence as a potential monitoring tool for recycled water systems: A review. Water Res. 2009, 43 (4), 863– 881,  DOI: 10.1016/j.watres.2008.11.027
      Google Scholar
      4
      Fluorescence as a potential monitoring tool for recycled water systems: A review
      Henderson, R. K.; Baker, A.; Murphy, K. R.; Hambly, A.; Stuetz, R. M.; Khan, S. J.
      Water Research (2009), 43 (4), 863-881CODEN: WATRAG; ISSN:0043-1354. (Elsevier Ltd.)
      A review. A rapid, highly sensitive and selective detector is urgently required to detect contamination events in recycled water systems, for example, cross-connection events in dual reticulation pipes that recycle advanced treated sewage effluent, as existing technologies, including total org. carbon and cond. monitoring, cannot always provide the sensitivity required. Fluorescence spectroscopy has been suggested as a potential monitoring tool given its high sensitivity and selectivity. A review of recent literature demonstrates that by monitoring the fluorescence of dissolved org. matter (DOM), the ratios of humic-like (Peak C) and protein-like (Peak T) fluorescence peaks can be used to identify trace sewage contamination in river waters and estuaries, a situation analogous to contamination detection in recycled water systems. Addnl., strong correlations have been shown between Peak T and BOD in rivers, which is indicative of water impacted by microbial activity and therefore of sewage impacted systems. Hence, this review concludes that the sensitive detection of contamination events in recycled water systems may be achieved by monitoring Peak T and/or Peak C fluorescence. However, in such systems, effluent is treated to a high std. resulting in much lower DOM concns. and the impact of these advanced treatment processes on Peaks T and C fluorescence is largely unknown and requires investigation. This review has highlighted that further work is also required to det. (a) the stability and distinctiveness of recycled water fluorescence in relation to the treatment processes utilized, (b) the impact of matrix effects, particularly the impact of oxidn., (c) calibration issues for online monitoring, and (d) the advanced data anal. techniques required, if any, to improve detection of contamination events.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD1MXisVGjtLo%253D&md5=421313a3a89b1a5d1769d4c7a38ea75c
    5. 5
      Tchobanoglous, G.; Cotruvo, J.; Crook, J.; McDonald, E.; Olivieri, A.; Salveson, A.; Trussell, R. S. Framework for direct potable reuse; WateReuse Association, American Water Works Association, Water Environment Federation, National Water Research Institute: Alexandria, VA, 2015.
      Google Scholar
      There is no corresponding record for this reference.
    6. 6
      Potable reuse: guidance for producing safe drinking-water; World Health Organization: Geneva, 2017.
      Google Scholar
      There is no corresponding record for this reference.
    7. 7
      Examining the Criteria for Direct Potable Reuse. WateReuse Research Foundation Project 11-02; National Water Research Institute: Fountain Valley, CA, 2013.
      Google Scholar
      There is no corresponding record for this reference.
    8. 8
      Lopez-Roldan, R.; Tusell, P.; Cortina, J. L.; Courtois, S.; Cortina, J. L. On-line bacteriological detection in water. TrAC, Trends Anal. Chem. 2013, 44, 46– 57,  DOI: 10.1016/j.trac.2012.10.010
      Google Scholar
      8
      On-line bacteriological detection in water
      Lopez-Roldan, Ramon; Tusell, Pol; Cortina, Jose Luis; Courtois, Sophie
      TrAC, Trends in Analytical Chemistry (2013), 44 (), 46-57CODEN: TTAEDJ; ISSN:0165-9936. (Elsevier B. V.)
      A review. Microorganism contamination is a permanent concern in a wide range of fields, including the water-treatment, food and pharmaceutical industries, in which fast detection is crit. to prevent microbial outbreaks. In water monitoring, current procedures for water-quality anal. are based on periodic sampling and detection by culture methods, which are slow, requiring 24-48 h for completion, so that, when first results reach the decision-takers and trigger an alarm, significant time has already passed and the population may have been exposed to a health hazard. There is a need for rapid, reliable detection of contaminants in a broad spectrum of water-management situations. For real-time detection, online monitoring seems to be the ideal approach, but the need to adjust the available techniques to autonomous operation and the optimization of response time are substantial challenges. This review presents the findings of an identification study about the state-of-the-art of technologies and com. devices for online biomonitoring of water quality, specifically for the detection of fecal contamination. We also include studies dealing with verification or use of these devices.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXktFWqu74%253D&md5=3aeb7cd8994db5c9f11c3aba18380bde
    9. 9
      Van Nevel, S.; Koetzsch, S.; Proctor, C. R.; Besmer, M. D.; Prest, E. I.; Vrouwenvelder, J. S.; Knezev, A.; Boon, N.; Hammes, F. Flow cytometric bacterial cell counts challenge conventional heterotrophic plate counts for routine microbiological drinking water monitoring. Water Res. 2017, 113, 191– 206,  DOI: 10.1016/j.watres.2017.01.065
      Google Scholar
      9
      Flow cytometric bacterial cell counts challenge conventional heterotrophic plate counts for routine microbiological drinking water monitoring
      Van Nevel, S.; Koetzsch, S.; Proctor, C. R.; Besmer, M. D.; Prest, E. I.; Vrouwenvelder, J. S.; Knezev, A.; Boon, N.; Hammes, F.
      Water Research (2017), 113 (), 191-206CODEN: WATRAG; ISSN:0043-1354. (Elsevier Ltd.)
      A review with many refs. Drinking water utilities and researchers continue to rely on the century-old heterotrophic plate counts (HPC) method for routine assessment of general microbiol. water quality. Bacterial cell counting with flow cytometry (FCM) is one of a no. of alternative methods that challenge this status quo and provide an opportunity for improved water quality monitoring. After more than a decade of application in drinking water research, FCM methodol. is optimized and established for routine application, supported by a considerable amt. of data from multiple full-scale studies. Bacterial cell concns. obtained by FCM enable quantification of the entire bacterial community instead of the minute fraction of cultivable bacteria detected with HPC (typically < 1% of all bacteria). FCM measurements are reproducible with relative std. deviations below 3% and can be available within 15 min of samples arriving in the lab. High throughput sample processing and complete automation are feasible and FCM anal. is arguably less expensive than HPC when measuring more than 15 water samples per day, depending on the lab. and selected staining procedure(s). Moreover, many studies have shown FCM total (TCC) and intact (ICC) cell concns. to be reliable and robust process variables, responsive to changes in the bacterial abundance and relevant for characterizing and monitoring drinking water treatment and distribution systems. The purpose of this crit. review is to initiate a constructive discussion on whether FCM could replace HPC in routine water quality monitoring. We argue that FCM provides a faster, more descriptive and more representative quantification of bacterial abundance in drinking water.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXivFWksLk%253D&md5=ceef2c8759cac828271b3eabd0a5f4d8
    10. 10
      Prest, E. I.; Hammes, F.; Kötzsch, S.; van Loosdrecht, M. C. M.; Vrouwenvelder, J. S. Monitoring microbiological changes in drinking water systems using a fast and reproducible flow cytometric method. Water Res. 2013, 47 (19), 7131– 7142,  DOI: 10.1016/j.watres.2013.07.051
      Google Scholar
      10
      Monitoring microbiological changes in drinking water systems using a fast and reproducible flow cytometric method
      Prest, E. I.; Hammes, F.; Koetzsch, S.; van Loosdrecht, M. C. M.; Vrouwenvelder, J. S.
      Water Research (2013), 47 (19), 7131-7142CODEN: WATRAG; ISSN:0043-1354. (Elsevier Ltd.)
      Flow cytometry (FCM) is a rapid, cultivation-independent tool to assess and evaluate bacteriol. quality and biol. stability of water. Here we demonstrate that a stringent, reproducible staining protocol combined with fixed FCM operational and gating settings is essential for reliable quantification of bacteria and detection of changes in aquatic bacterial communities. Triplicate measurements of diverse water samples with this protocol typically showed relative std. deviation values and 95% confidence interval values below 2.5% on all the main FCM parameters. We propose a straightforward and instrument-independent method for the characterization of water samples based on the combination of bacterial cell concn. and fluorescence distribution. Anal. of the fluorescence distribution (or so-called fluorescence fingerprint) was accomplished firstly through a direct comparison of the raw FCM data and subsequently simplified by quantifying the percentage of large and brightly fluorescent high nucleic acid (HNA) content bacteria in each sample. Our approach enables fast differentiation of dissimilar bacterial communities (less than 15 min from sampling to final result), and allows accurate detection of even small changes in aquatic environments (detection above 3% change). Demonstrative studies on (a) indigenous bacterial growth in water, (b) contamination of drinking water with wastewater, (c) household drinking water stagnation and (d) mixing of two drinking water types, univocally showed that this FCM approach enables detection and quantification of relevant bacterial water quality changes with high sensitivity. This approach has the potential to be used as a new tool for application in the drinking water field, e.g. for rapid screening of the microbial water quality and stability during water treatment and distribution in networks and premise plumbing.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3sXhslSnsL7N&md5=3a7d0382b1137097e3f6bfa8f6d899a4
    11. 11
      Sherchan, S. P.; Gerba, C. P.; Pepper, I. L. Evaluation of Real-Time Water Quality Sensors for the Detection of Intentional Bacterial Spore Contamination of Potable Water. J. Biosens. Bioelectron. 2013, 4 (4), 1– 5,  DOI: 10.4172/2155-6210.1000141
      Google Scholar
      There is no corresponding record for this reference.
    12. 12
      Miles, S. L.; Sinclair, R. G.; Riley, M. R.; Pepper, I. L. Evaluation of Select Sensors for Real-Time Monitoring of Escherichia coli in Water Distribution Systems. Appl. Environ. Microbiol. 2011, 77 (8), 2813– 2816,  DOI: 10.1128/AEM.02618-10
      Google Scholar
      There is no corresponding record for this reference.
    13. 13
      Ammor, M. S. Recent Advances in the Use of Intrinsic Fluorescence for Bacterial Identification and Characterization. J. Fluoresc. 2007, 17 (5), 455– 459,  DOI: 10.1007/s10895-007-0180-6
      Google Scholar
      13
      Recent advances in the use of intrinsic fluorescence for bacterial identification and characterization
      Ammor, Mohammed Salim
      Journal of Fluorescence (2007), 17 (5), 455-459CODEN: JOFLEN; ISSN:1053-0509. (Springer)
      A review. Live bacteria contain a variety of intracellular biomols. that have specific excitation and emission wavelength spectra characterizing their intrinsic fluorescence. This paper reviews recent developed methods using bacterial intrinsic fluorescence for identification and characterization purposes. Potential applications of such methods at the industrial level are also addressed.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BD2sXpt1yksLY%253D&md5=60d25495c36bca4404a4ae6505780458
    14. 14
      Huang, X.; Zhao, Z.; Hernandez, D.; Jiang, S. Near Real-Time Flow Cytometry Monitoring of Bacterial and Viral Removal Efficiencies during Water Reclamation Processes. Water 2016, 8 (10), 464,  DOI: 10.3390/w8100464
      Google Scholar
      There is no corresponding record for this reference.
    15. 15
      Miller, S. E.; Nelson, K. L.; Rodriguez, R. A. Microbiological Stability in Direct Potable Reuse Systems: Insights from Pilot-Scale Research Using Flow Cytometry and High-Throughput Sequencing. Proceedings of the Water Environment Federation 2017, 2017 (14), 1016– 1023,  DOI: 10.2175/193864717822153779
      Google Scholar
      There is no corresponding record for this reference.
    16. 16
      Pepper, I. L.; Snyder, S. A. Monitoring for reliability and process control of potable reuse applications; Water Environment & Reuse Foundation and IWA Publishing: Alexandria, VA, 2016.
      Google Scholar
      There is no corresponding record for this reference.
    17. 17
      Fujioka, T.; Kodamatani, H.; Aizawa, H.; Gray, S.; Ishida, K. P.; Nghiem, L. D. Role of membrane fouling substances on the rejection of N-nitrosamines by reverse osmosis. Water Res. 2017, 118, 187– 195,  DOI: 10.1016/j.watres.2017.03.057
      Google Scholar
      There is no corresponding record for this reference.
    18. 18
      Liu, T.; Chen, Z.-l.; Yu, W.-z.; You, S.-j. Characterization of organic membrane foulants in a submerged membrane bioreactor with pre-ozonation using three-dimensional excitation–emission matrix fluorescence spectroscopy. Water Res. 2011, 45 (5), 2111– 2121,  DOI: 10.1016/j.watres.2010.12.023
      Google Scholar
      18
      Characterization of organic membrane foulants in a submerged membrane bioreactor with pre-ozonation using three-dimensional excitation-emission matrix fluorescence spectroscopy
      Liu, Ting; Chen, Zhong-lin; Yu, Wen-zheng; You, Shi-jie
      Water Research (2011), 45 (5), 2111-2121CODEN: WATRAG; ISSN:0043-1354. (Elsevier B.V.)
      This study focuses on org. membrane foulants in a submerged membrane bioreactor (MBR) process with pre-ozonation compared to an individual MBR using three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy. While the influent was continuously ozonated at a normal dosage, preferable org. matter removal was achieved in subsequent MBR, and trans-membrane pressure increased at a much lower rate than that of the individual MBR. EEM fluorescence spectroscopy was employed to characterize the dissolved org. matter (DOM) samples, extracellular polymeric substance (EPS) samples and membrane foulants. Four main peaks could be identified from the EEM fluorescence spectra of the DOM samples in both MBRs. Two peaks were assocd. with the protein-like fluorophores, and the other ones were related to the humic-like fluorophores. The results indicated that pre-ozonation decreased fluorescence intensities of all peaks in the EEM spectra of influent DOM esp. for protein-like substances and caused red shifts of all fluorescence peaks to different extents. The peak intensities of the protein-like substances represented by Peak T1 and T2 in EPS spectra were obviously decreased as a result of pre-ozonation. Both external and internal fouling could be effectively mitigated by the pre-ozonation. The most primary component of external foulants was humic acid-like substance (Peak C) in the MBR with pre-ozonation and protein-like substance (Peak T1) in the individual MBR, resp. The content decrease of protein-like substances and structural change of humic-like substances were obsd. in external foulants from EEM fluorescence spectra due to pre-ozonation. However, it could be seen that ozonation resulted in significant redn. of intensities but little location shift of all peaks in EEM fluorescence spectra of internal foulants.
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      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC3MXitFaqurY%253D&md5=d8862c5f758d9b4d58f6d80045804e9d
    19. 19
      Nam, S.-N.; Amy, G. Differentiation of wastewater effluent organic matter (EfOM) from natural organic matter (NOM) using multiple analytical techniques. Water Sci. Technol. 2008, 57 (7), 1009– 1015,  DOI: 10.2166/wst.2008.165
      Google Scholar
      19
      Differentiation of wastewater effluent organic matter (EfOM) from natural organic matter (NOM) using multiple analytical techniques
      Nam, Seong-Nam; Amy, Gary
      Water Science and Technology (2008), 57 (7), 1009-1015CODEN: WSTED4; ISSN:0273-1223. (IWA Publishing)
      Using three anal. techniques of size exclusion chromatog. (SEC), fluorescence excitation-emission matrix (EEM), and dissolved org. nitrogen (DON) measurement, differentiating characteristics of effluent org. matter (EfOM) from natural org. matter (NOM) have been investigated. SEC reveals a wide range of mol. wt. (MW) for EfOM and high amt. of high MW polysaccharides, and low MW org. acids compared to NOM. Clear protein-like peaks using fluorescence EEM were a major feature of EfOM distinguishing it from NOM. Fluorescence index (FI), an indicator to distinguish autochthonous origin from allochthonous origin, differentiated EfOM from NOM by exhibiting higher values, indicating a microbial origin. In EfOM samples, DON present in higher amts. than NOM.
      >> More from SciFinder ®
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    20. 20
      Chen, W.; Westerhoff, P.; Leenheer, J. A.; Booksh, K. Fluorescence excitation–emission matrix regional integration to quantify spectra for dissolved organic matter. Environ. Sci. Technol. 2003, 37 (24), 5701– 5710,  DOI: 10.1021/es034354c
      Google Scholar
      20
      Fluorescence Excitation-Emission Matrix Regional Integration to Quantify Spectra for Dissolved Organic Matter
      Chen, Wen; Westerhoff, Paul; Leenheer, Jerry A.; Booksh, Karl
      Environmental Science and Technology (2003), 37 (24), 5701-5710CODEN: ESTHAG; ISSN:0013-936X. (American Chemical Society)
      Excitation-emission matrix (EEM) fluorescence spectroscopy has been widely used to characterize dissolved org. matter (DOM) in water and soil. However, interpreting the >10,000 wavelength-dependent fluorescence intensity data points represented in EEMs has posed a significant challenge. Fluorescence regional integration, a quant. technique that integrates the vol. beneath an EEM, was developed to analyze EEMs. EEMs were delineated into five excitation-emission regions based on the fluorescence of model compds., DOM fractions, and marine waters or fresh waters. Volumetric integration under the EEM within each region, normalized to the projected excitation-emission area within that region and dissolved org. carbon concn., resulted in a normalized region-specific EEM vol. (Φi,n). Solid-state carbon NMR (13C NMR), Fourier transform IR (FTIR) anal., UV-visible absorption spectra, and EEMs were obtained for std. Suwannee River fulvic acid and 15 hydrophobic or hydrophilic acid, neutral, and base DOM fractions plus nonfractionated DOM from wastewater effluents and rivers in the southwestern USA. DOM fractions fluoresced in one or more EEM regions. The highest cumulative EEM vol. (ΦT,n = ΣΦi,n) was obsd. for hydrophobic neutral DOM fractions, followed by lower ΦT,n values for hydrophobic acid, base, and hydrophilic acid DOM fractions, resp. An extd. wastewater biomass DOM sample contained arom. protein- and humic-like material and was characteristic of bacterial sol. microbial products. Arom. carbon and the presence of specific arom. compds. (as indicated by solid-state 13C NMR and FTIR data) resulted in EEMs that aided in differentiating wastewater effluent DOM from drinking water DOM.
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    21. 21
      Prest, E. I.; Hammes, F.; van Loosdrecht, M. C. M.; Vrouwenvelder, J. S. Biological Stability of Drinking Water: Controlling Factors, Methods, and Challenges. Front. Microbiol. 2016, 7 (45), 1– 24,  DOI: 10.3389/fmicb.2016.00045
      Google Scholar
      There is no corresponding record for this reference.
    22. 22
      Ou, F.; McGoverin, C.; Swift, S.; Vanholsbeeck, F. Absolute bacterial cell enumeration using flow cytometry. J. Appl. Microbiol. 2017, 123 (2), 464– 477,  DOI: 10.1111/jam.13508
      Google Scholar
      22
      Absolute bacterial cell enumeration using flow cytometry
      Ou, F.; McGoverin, C.; Swift, S.; Vanholsbeeck, F.
      Journal of Applied Microbiology (2017), 123 (2), 464-477CODEN: JAMIFK; ISSN:1364-5072. (Wiley-Blackwell)
      Aim : To evaluate a flow cytometry protocol that uses ref. beads for the enumeration of live and dead bacteria present in a mixt. Methods and Results : Mixts. of live and dead Escherichia coli with live:dead concn. ratios varying from 0 to 100% were prepd. These samples were stained using SYTO 9 and propidium iodide and 6-μm ref. beads were added. Bacteria present in live samples were enumerated by agar plate counting. Bacteria present in dead samples were enumerated by agar plate counting before treatment with isopropanol. There is a linear relationship between the presented flow cytometry method and agar plate counts for live (R2 = 0·99) and dead E. coli (R2 = 0·93) concns. of c. 104 to 108 bacteria per mL within mixts. of live and dead bacteria. Conclusions : Reliable enumeration of live E. coli within a mixt. of both live and dead was possible for concn. ratios of above 2·5% live and for the enumeration of dead E. coli the lower limit was c. 20% dead. Significance and Impact of the Study : The ability to obtain abs. cell concns. is only available for selected flow cytometers, this study describes a method for accurate enumeration that is applicable to basic flow cytometers without specialized counting features. By demonstrating the application of the method to count E. coli, we raised points of consideration for using this FCM counting method and aim to lay the foundation for future work that uses similar methods for different bacterial strains.
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      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2sXhtF2it73L&md5=0a6049fd8837aaa10684393c97df2e2a
    23. 23
      Fujioka, T.; Oshima, N.; Suzuki, R.; Khan, S. J.; Roux, A.; Poussade, Y.; Drewes, J. E.; Nghiem, L. D. Rejection of small and uncharged chemicals of emerging concern by reverse osmosis membranes: The role of free volume space within the active skin layer. Sep. Purif. Technol. 2013, 116, 426– 432,  DOI: 10.1016/j.seppur.2013.06.015
      Google Scholar
      23
      Rejection of small and uncharged chemicals of emerging concern by reverse osmosis membranes: The role of free volume space within the active skin layer
      Fujioka, Takahiro; Oshima, Nagayasu; Suzuki, Ryoichi; Khan, Stuart J.; Roux, Annalie; Poussade, Yvan; Drewes, Jorg E.; Nghiem, Long D.
      Separation and Purification Technology (2013), 116 (), 426-432CODEN: SPUTFP; ISSN:1383-5866. (Elsevier B.V.)
      Free-vol. hole-radii of the active skin layer of one seawater and 2 low pressure reverse osmosis (RO) membranes, namely SWC5, ESPAB, and ESPA2, resp., were evaluated using positron annihilation lifetime spectroscopy (PALS) with a slow positron beam. The results were related to the rejection of boric acid and eight N-nitrosamines to provide insights to the transport of these small solutes through RO membranes. At pH 8 (which is the exptl. pH in this study), these solutes are uncharged. PALS anal. showed that the SWC5 has the smallest mean free-vol. hole-radius (0.259 nm) among the three RO membranes studied. Correspondingly, the SWC5 membrane exhibited the highest rejection of boric acid and all N-nitrosamines. Results reported here also showed that the rejection of these chems. increased in the order of increasing mol. vol. The difference in their rejection amongst the 3 RO membranes studied was most apparent for those (i.e., boric acid and N-nitrosodimethylamine (NDMA)) with a small mol. vol. The EPSA2 and ESPAB were detd. to have mean free-vol. hole-radius of 0.289 nm. However, the ESPAB membrane had lower water permeability and showed considerably higher rejection of boric acid and NDMA than the ESPA2 membrane. These results suggest that in addn. to the mean free-vol. hole-radius, other membrane parameters and properties such as the free-vol. hole-radius distribution and thickness of the active skin layer can also play a role in governing the rejection of small and uncharged solutes by RO membranes.
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    24. 24
      Park, S.; Hu, J. Y. Assessment of the extent of bacterial growth in reverse osmosis system for improving drinking water quality. J. Environ. Sci. Health, Part A: Toxic/Hazard. Subst. Environ. Eng. 2010, 45 (8), 968– 977,  DOI: 10.1080/10934521003772386
      Google Scholar
      There is no corresponding record for this reference.
    25. 25
      Ishida, K. P.; Cooper, W. J. Analysis of parameters affecting process efficiency, energy consumption, and carbon footprint in water reuse; WateReuse Research Foundation: Alexandria, VA, 2015.
      Google Scholar
      There is no corresponding record for this reference.
    26. 26
      Liikanen, R.; Miettinen, I.; Laukkanen, R. Selection of NF membrane to improve quality of chemically treated surface water. Water Res. 2003, 37 (4), 864– 872,  DOI: 10.1016/S0043-1354(02)00412-8
      Google Scholar
      There is no corresponding record for this reference.
    27. 27
      Laurent, P.; Servais, P.; Gatel, D.; Randon, G.; Bonne, P.; Cavard, J. Microbiological quality: Before and after nanofiltration. J. - Am. Water Works Assoc. 1999, 91 (10), 62– 72,  DOI: 10.1002/j.1551-8833.1999.tb08716.x
      Google Scholar
      27
      Microbiological quality before and after nanofiltration
      Laurent, Patrick; Servais, Pierre; Gatel, Dominique; Randon, Guy; Bonne, Pascal; Cavard, Jacques
      Journal - American Water Works Association (1999), 91 (10), 62-72CODEN: JAWWA5; ISSN:0003-150X. (American Water Works Association)
      The authors investigated microbiol. behavior of a distribution system supplied initially with biol. treated water and then with nanofiltered water. Their purpose was to identify and evaluate the changes in microbiol. water quality attributable to modifications in water treatment at the plant. During the course of the study, all data from various indicators of microbiol. quality (i.e., heterotrophic plate counts, coliform enumeration, total direct counts, and fixed bacterial biomass) showed similar trends. Results indicated that the use of nanofiltration allows utilities to reduce chlorination of treated water and at least maintain or increase the microbiol. quality of distributed water for areas with high residence times.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADyaK1MXmslOrur4%253D&md5=b2aa68eb9a35ed9dee6bc8f496b2dadc
    28. 28
      Pype, M.-L.; Lawrence, M. G.; Keller, J.; Gernjak, W. Reverse osmosis integrity monitoring in water reuse: The challenge to verify virus removal – A review. Water Res. 2016, 98, 384– 395,  DOI: 10.1016/j.watres.2016.04.040
      Google Scholar
      28
      Reverse osmosis integrity monitoring in water reuse: The challenge to verify virus removal - A review
      Pype, Marie-Laure; Lawrence, Michael G.; Keller, Jurg; Gernjak, Wolfgang
      Water Research (2016), 98 (), 384-395CODEN: WATRAG; ISSN:0043-1354. (Elsevier Ltd.)
      A review with many refs. A reverse osmosis (RO) process is often included in the treatment train to produce high quality reuse water from treated effluent for potable purposes because of its high removal efficiency for salinity and many inorg. and org. contaminants, and importantly, it also provides an excellent barrier for pathogens. In order to ensure the continued protection of public health from pathogen contamination, monitoring RO process integrity is necessary. Due to their small sizes, viruses are the most difficult class of pathogens to be removed in phys. sepn. processes and therefore often considered the most challenging pathogen to monitor. To-date, there is a gap between the current log credit assigned to this process (detd. by integrity testing approved by regulators) and its actual log removal capability as proven in a variety of lab. and pilot studies. Hence, there is a challenge to establish a methodol. that more closely links to the theor. performance. In this review, after introducing the notion of risk management in water reuse, we provide an overview of existing and potentially new RO integrity monitoring techniques, highlight their strengths and drawbacks, and debate their applicability to full-scale treatment plants, which open to future research opportunities.
      >> More from SciFinder ®
      https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC28XnvFSjsbw%253D&md5=f397be33b159a97d02ccfce38be68652
    29. 29
      Liu, G.; Lut, M. C.; Verberk, J. Q. J. C.; Van Dijk, J. C. A comparison of additional treatment processes to limit particle accumulation and microbial growth during drinking water distribution. Water Res. 2013, 47 (8), 2719– 2728,  DOI: 10.1016/j.watres.2013.02.035
      Google Scholar
      There is no corresponding record for this reference.

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