TY - JOUR
T1 - Assessment of online bacterial particle counts for monitoring the performance of reverse osmosis membrane process in potable reuse
AU - Fujioka, Takahiro
AU - Makabe, Ryo
AU - Mori, Naomichi
AU - Snyder, Shane A.
AU - Leddy, Menu
N1 - Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/6/1
Y1 - 2019/6/1
N2 - Safety of potable reuse can be enhanced by improved water quality monitoring techniques for assessing water treatment processes. This study evaluated the efficacy of online bacterial counting for continuous monitoring of reverse osmosis (RO) membranes to remove bacteria using real-time bacteriological commercial counters and an on-site pilot-scale RO system. Prior to on-site assessments, the online bacterial counting was verified by comparing the measurement of fluorescent particles in water with flow cytometry. During a seven day pilot test of RO treatment at a water reclamation plant, online bacterial counts in RO permeate were monitored below 15 counts/mL; whereas the bacterial counts in RO feed water were approximately 2500 to 10,000 counts/mL. Removal rates of bacterial counts ranged from 2.6 to 3.1-log (average = 2.9-log) by continuously monitoring bacterial removal. This is greater than a 2-log reduction frequently determined using other water quality surrogates (i.e., electrical conductivity). Overall, the continuous monitoring of bacteria in RO feed and permeate can be implemented without the addition of chemicals to provide near real-time bacterial counts to measure their reduction after RO treatment. This can be developed for continuous performance monitoring of the RO process, providing greater assurance of microbial water quality after RO treatment.
AB - Safety of potable reuse can be enhanced by improved water quality monitoring techniques for assessing water treatment processes. This study evaluated the efficacy of online bacterial counting for continuous monitoring of reverse osmosis (RO) membranes to remove bacteria using real-time bacteriological commercial counters and an on-site pilot-scale RO system. Prior to on-site assessments, the online bacterial counting was verified by comparing the measurement of fluorescent particles in water with flow cytometry. During a seven day pilot test of RO treatment at a water reclamation plant, online bacterial counts in RO permeate were monitored below 15 counts/mL; whereas the bacterial counts in RO feed water were approximately 2500 to 10,000 counts/mL. Removal rates of bacterial counts ranged from 2.6 to 3.1-log (average = 2.9-log) by continuously monitoring bacterial removal. This is greater than a 2-log reduction frequently determined using other water quality surrogates (i.e., electrical conductivity). Overall, the continuous monitoring of bacteria in RO feed and permeate can be implemented without the addition of chemicals to provide near real-time bacterial counts to measure their reduction after RO treatment. This can be developed for continuous performance monitoring of the RO process, providing greater assurance of microbial water quality after RO treatment.
KW - Flow cytometer
KW - Integrity monitoring
KW - Potable water reuse
KW - RO membrane
KW - Real-time bacterial count
UR - http://www.scopus.com/inward/record.url?scp=85062375435&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85062375435&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2019.02.339
DO - 10.1016/j.scitotenv.2019.02.339
M3 - Article
C2 - 30833252
AN - SCOPUS:85062375435
VL - 667
SP - 540
EP - 544
JO - Science of the Total Environment
JF - Science of the Total Environment
SN - 0048-9697
ER -