Morris, Larry, Morris

Larry is the Deputy General Manager of Research & Development for Kubota Membrane USA Corporation. His primary focus is developing and...

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About Morris, Larry

Larry is the Deputy General Manager of Research & Development for Kubota Membrane USA Corporation. His primary focus is developing and improving flat plate membranes and MBR systems for wastewater treatment and reuse applications. He holds a PhD in physical inorganic chemistry from Michigan State University and a BS in chemistry from Lipscomb University.

Morris, Larry

Titles from this speaker

Performance Evaluation of an Online Membrane Integrity Monitor for Flat Plate MBRs

Abstract

Incorporating membrane bioreactors (MBR) into potable reuse treatment trains is gaining interest due to increasing concerns over water scarcity and the need for high quality effluent for downstream treatment technologies. However, membranes are vulnerable to breaches which necessitates real-time monitoring of membrane integrity. Turbidity monitoring is applied ubiquitously in the field, but it is difficult to correlate with microbial reduction performance. To this end, a novel online integrity monitor was developed and evaluated at a 30,000 gal/d MBR pilot in Canton, OH. This monitor detects changes in permeate quality by quantifying the fouling of a dead-end membrane external to the MBR treatment process via flow and pressure measurements. Figure 1 details the configuration of the integrity monitor. The performance of the integrity monitor was validated by intentionally creating membrane breaches. Slits were cut into the membranes of one module prior to installation and were protected with tape and tied to strings that could be removed by operators for control of breach timing. The intensity of damage was controlled by varying the number of slits in three phases separated by 24 hours; three slits (Phase 1), followed by 28 slits (Phase 2) and finally 63 slits (Phase 3), totaling 94 slits (Table 1.). Membrane integrity was monitored using two online instruments: a commercially available laser-based turbidimeter and the novel membrane integrity monitor. The integrity monitor provided two parameters used for comparison with turbidity including the resistance (transmembrane pressure/flux) and the graphical first derivative of the resistance. Log reduction values (LRV) of male specific and somatic coliphages, E. Coli and total coliforms were assessed before and after breaches for comparison with the real-time data. Baseline MBR effluent turbidity was <0.04 NTU; after Phase 1 damage was uncovered, turbidity briefly spiked above 1.0 NTU, but recovered to pre-damaged conditions. Initial results (Figure 2) suggest that membrane breaches can be reliably detected by the prototype integrity monitor. Breaches were detected when the derivative of the resistance (αR) was > 1.05; turbidity and microbial results corroborated the response of the integrity monitor. The resistance increased positively over the three phases from 0.5 to > 8.0 psi/gal/ft2/d while αR detected the second phase breach (28 slits) with a marked response (Figure 2). It is possible that the three slits of Phase 1 did not produce a response because it was simply too small of a breach; it is possible that the mixed liquor may have provided a 'band-aid' effect in where the slits were covered by mixed liquor during filtration, disallowing particle passage into the permeate. Work is ongoing to determine the lower limits of sensitivity of the monitor by varying parameters and configuration. LRVs of male specific coliphages fell from approximately 3- to < 2-log but recovered after approximately one hour of operation. Total coliform and E. Coli LRVs reduced from 7.2 and 6.7-log, to 4.2 and 3.8-log, respectively; the LRVs remained stable after this initial drop. Microbial response to the breaches can be seen in Figure 3. This presentation and paper show progress towards developing a sensitive, integrity monitor that will reliably detect membrane breaches in real time. Work is ongoing to improve the sensitivity of the device, identify patterns in the data it produces, and correlate its results to microbial reduction performance.

A membrane integrity monitor for flat plate MBR has been developed and tested in a pilot scale MBR-RO treatment train. The monitor detects changes in permeate quality by quantifying the fouling of a dead-end membrane external to the MBR treatment process via flow and pressure measurements. The performance of the integrity monitor was validated by intentionally creating membrane breaches, observing the instrumental response and comparing with online turbidity measurements as well as as data

SpeakerMorris, Larry

Presentation time

09:15:00

09:30:00

Session time

08:30:00

10:00:00

SessionEnhancing Water Safety: MBR & RO Technologies for Achieving LRV Credits

Session number315

Session locationRoom 349

TopicAdvanced Level, Disinfection and Public Health, Microconstituents and Contaminants of Emerging Concern (Non-PFAS), Municipal Wastewater Treatment Design, Water Reuse and Reclamation

Author(s)

Morris, Larry, Terao, Yasushi, Shimizu, Nao, Jacangelo, Joseph, Lehman, Geno, Adelman, Michael, Messologitis, Katerina, Bruce, Eric, Glover, Caitlin, Ryan, Donald

Author(s)L. Morris1, Y. Terao1, N. Shimizu1, J. Jacangelo2, G. Lehman3, M.J. Adelman3, K. Messologitis4, E. Bruce3, C. Glover5, D. Ryan6

Author affiliation(s)1Kubota Membrane USA Corporation, OH, 2, VA, 3Stantec, CA, 4Stantec, OR, 5Stantec, 6, WI

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2024

DOI10.2175/193864718825159560

Volume / Issue

Content sourceWEFTEC

Word count13

RO Fouling Assessment of MBR-RO Trains using Flat-Plate MBR Membranes

Abstract

There is growing interest in using membrane bioreactors (MBR) for potable reuse because of their improved effluent quality and pathogen removal compared to conventional secondary processes. Therefore, using an MBR as the main treatment process upstream of reverse osmosis (RO) is often desirable for advanced treatment facilities. Most advanced treatment studies with MBRs employ hollow fiber or tubular membranes. In this 12- month pilot study, an alternative flat-plate MBR was employed as the pretreatment method to assess downstream biological and colloidal RO fouling in a MBR-RO train. The study evaluated RO performance under varying operational parameters such as MBR and RO flux conditions, biological process conditions in the MBR, and chloramine dose in the RO feed. The RO system was also subject to known MBR membrane breaches. The two-stage RO system was operated at ~70% recovery to avoid mineral scaling so the effects of fouling driven by MBR filtrate quality could be observed. Typical RO permeate flux values used in reuse applications (10-14 gfd) were used in this study. Key monitoring parameters included MLSS, TMP, and filtrate water quality for the MBR as well as normalized RO specific flux. A novel online integrity monitor was also used to detect small colloidal particles in the RO feed using differential pressure across a filter. RO membranes were also periodically sent for autopsy to evaluate the type of fouling observed on the RO membranes prior to a clean-in-place. Normalized RO data has shown evidence of periods with both higher and lower rates of fouling. RO flux decline data was plotted against key MBR operating and filtrate quality parameters. The MBR filtrate turbidity and integrity monitor data showed notable correlations. Lowest RO fouling rates (< 0.0003 gfd/psi-day) were observed with lower filtrate turbidity and lower differential pressure from the integrity monitor. Higher fouling rates (> 0.0003 gfd/psi-day) took place at higher MBR permeate sCOD (>30 mg/L) and low chloramine levels, both of which would favor biofilm growth as a driver of fouling. However, autopsy results showed mostly organic material as the foulant with minimal biofilm coverage suggesting that colloids were the main driver of fouling with biological growth as a secondary factor. Normalized RO data was evaluated individually for stage 1 and stage 2. Conventional knowledge would suggest that colloidal fouling in RO systems is more prevalent at the first stage than in subsequent stages. However, the results from this study suggests that the RO fouling pattern is similar between stage 1 and stage 2 membranes, as shown in Figure 1. The performance of the MBR-RO pilot using flat-plate MBR membranes was compared to existing data from MBR-RO treatment processes using hollow fiber or tubular MBR membrane, which suggests that the type of MBR membrane used upstream of the RO system does not impact the overall performance of the RO system. Table 1 provides RO performance data from two reference facilities compared to the performance observed during this pilot study. This presentation will provide insights into the drivers of RO fouling as well as operational strategies for improved RO performance, and will compare the performance of this pilot study against existing process data from other advanced water treatment plant facilities. Target values for MBR filtrate turbidity, MBR tank MLSS, and feed chloramines were identified as parameters that promote low fouling rates and reasonable CIP intervals. The novel integrity monitor was shown to provide useful insight into whether colloid passage was sufficient to increase RO fouling rates.

There is growing interest in using MBRs upstream of RO for potable reuse because of their improved effluent quality & pathogen removal compared to conventional secondary processes. Well-developed models exist to predict mineral scaling in RO systems, however, biological & colloidal fouling in MBR-RO trains is less understood. A 12-month pilot study was conducted to evaluate fouling of RO membranes when used in combination with a flat-plate membrane bioreactor upstream of a pilot RO system.

SpeakerMessologitis, Katerina

Presentation time

14:00:00

14:30:00

Session time

13:30:00

15:00:00

SessionEffective Strategies for Managing Organics in IPR/DPR Systems

Session number216

Session locationRoom 340

TopicIntermediate Level, Water Reuse and Reclamation

Author(s)

Messologitis, Katerina, Morris, Larry, Terao, Yasushi, Jacangelo, Joseph, Adelman, Michael, Shimizu, Nao, Bruce, Eric, Lehman, Geno, Glover, Caitlin, Ryan, Donald

Author(s)K. Messologitis1, L. Morris2, Y. Terao2, J. Jacangelo3, M.J. Adelman4, N. Shimizu2, E. Bruce4, G. Lehman4, C. Glover5, D. Ryan5

Author affiliation(s)1Stantec, OR, 2Kubota Membrane USA Corporation, OH, 3, VA, 4Stantec, CA, 5Stantec

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2024

DOI10.2175/193864718825159588

Volume / Issue

Content sourceWEFTEC

Word count11

Description: Understanding The Mechanistic Contributions To Virus Removal In Membrane...

Understanding The Mechanistic Contributions To Virus Removal In Membrane Bioreactors

Abstract

Introduction and Background
Pathogen removal by MBRs has shown to be substantial; however, the credited log reduction values (LRV) are often conservatively downrated due to uncertainty in current and future ability to maintain performance. Based on a recent and extensive case study, Kubota flat sheet membranes have achieved average culturable human virus LRVs of 4.1 for both adenovirus and enterovirus. Protozoa LRVs have averaged >4.2 for Cryptosporidium and 5.2 for Giardia, with no Cryptosporidium detections in the filtrate. The Kubota membranes have an average pore size of 0.2 Âµm and are therefore reasoned to remove protozoa (typically > 3 Âµm). Viruses, however, are much smaller in comparison to the pore size (<0.1 Âµm), but case study results demonstrate significant removal. This study aims to further understand the mechanistic factors that contribute to enhanced virus removal observed in Kubota flat sheet MBR systems.
Methodology
To quantify the contributions of the separate pathogen removal mechanisms, experiments were designed to test mechanisms separately. Single strain male specific (MS2) and somatic (T1) coliphages were used as surrogates to assess virus removal. A two-day trial was conducted to investigate the extent of adsorption and biological degradation on model virus LRV. Activated sludge was sampled fresh from an MBR test plant in Canton, OH. The sludge was sent for characterization of indigenous male-specific and somatic coliphages. Experiments were conducted whereby the concentrations of spiked and indigenous male-specific coliphages were determined after various time periods and with centrifugation. LRV due to adsorption of indigenous coliphages was inferred by comparing the native well mixed activated sludge sample concentrations to centrifuged samples. Whereas, the extent of aerobic biological predation was determined by comparing the supernatant concentrations on day 1 to that of day 2 after 24 hours of aeration. See Figure 1 for an illustration of the experimental approach. Concerning biofilm plus membrane contribution to virus removal, a pilot plant was used to control biofilm growth over a period of time. The membranes in the pilot plant are flat sheet microfiltration style with a 0.2 Âµm average pore size. Following sufficient biofilm growth (fouling layer deposited on the membranes during operation), mixed liquor and filtrate samples were taken to determine native populations of MS2 and T1 coliphages. The mixed liquor was then spiked with both MS2 and T1 to determine virus removal of the entire system. The mixed liquor was then flushed from the membrane tank and filled with tap water, so as to not disturb the biofilm. This can be seen in Figure 2. Spikes were administered to the system and tap water and filtrate samples were taken; only the membranes and biofilm would be contributing to virus removal.
Results
Significant adsorption occurred rapidly for all spiked indicators; results show that of 10# 7 (MS2) and 10# 6 (T1) spiked organisms, 10# 4 (MS2) and 10# 3 (T1) were associated with sludge flocs. This indicates that initial adsorption may contribute 2.8 to 4.2 LRV. Figure 3 graphically shows that adsorption to sludge increases over time for both coliphages examined, in both anoxic and aerated conditions. Results indicate that biofilm plus membrane removal can contribute from one-fifth to upwards of one-half of the total removal. Average results from all experimental runs are displayed in Table 1. These results show that the biofilm plays a significant role in virus removal in microfiltration MBRs.
Conclusions
This study distinguishes between participating virus removal mechanisms in membrane bioreactors including adsorption to sludge and biofilm plus membrane removal utilizing male specific and somatic coliphages as surrogate microorganisms for human enteric viruses. It was shown that overtime, coliphage adsorption seemingly plateaus after several hours while biofilm contribution can vary, possibly due to environmental factors. Finally, these removal data were compared to an existing pathogen removal data set from a year-long case study of a full-scale Kubota MBR to verify the impact of the contributing mechanisms to actual virus removal upon scale up.

Pathogen removal by MBRs has shown to be substantial in that MBR is able to remove pathogens in line with evolving guidelines. Kubota flat plate membranes have achieved human virus LRVs averaging 3.9 for adenovirus and 4.9 for enterovirus genomic copies. Protozoa LRVs have averaged 3.6 for Cryptosporidium and 5.3 for Giardia. The membranes are reasoned to remove protozoa but viruses are being removed exceptionally. This study explores the underlying operable mechanisms of virus removal.

SpeakerMorris, Larry

Presentation time

14:00:00

14:15:00

Session time

13:30:00

15:00:00

TopicIntermediate Level, Disinfection and Public Health, Potable Reuse, Research and Innovation, Water Reuse and Reclamation

Author(s)

Morris, Larry

Author(s)Larry Morris1; Amos Branch2; Yasushi Terao3; Hiro Kuge4; Nicola Fontaine5

Author affiliation(s)Kubota Membrane USA Corporation, Canton, OH1; Carollo Engineers, Walnut Creek, CA2; Kubota Membrane USA Corporation, Canton, OH3; Kubota Membrane USA Corporation, Bothell, WA4; Carollo Engineers, Sacramento, CA5

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2022

DOI10.2175/193864718825158635

Volume / Issue

Content sourceWEFTEC

Word count11

Base text size -

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