• AWWA JAW59121
Provide PDF Format

Learn More

AWWA JAW59121

  • Journal AWWA - Microbial Removal and Integrity Monitoring of RO and NF Membranes
  • Journal Article by American Water Works Association, 12/01/2003
  • Publisher: AWWA

$15.00$30.00


The successful application of high-pressure membraneprocesses as effective barriers to pathogens requires theuse of online methods for monitoring and controlling membraneintegrity during process operation. Currently availableintegrity monitoring methods involving conductivity and totalorganic carbon have a resolution of only ~99% (2 log removal), butintact nanofiltration (NF) and reverse osmosis (RO) membranesand systems can provide much greater pathogen removal (>4 logs).Reliable and cost-effective integrity methods having equivalentresolution are needed in order for regulatory agencies to permit(and utilities to realize) the pathogen-removal credits for whichmembranes are capable.This research evaluated two new integrity monitoring methodsthat use nonmicrobial viral surrogates, fluorescent microspheresand fluorescent Rhodamine WT dye (RWT), to measure NF/ROmembrane and system integrity under both intact and compromisedconditions. Microsphere dosing to feedwater demonstratedviral removal at greater than the target level of 4 logs, but giventhe current cost of such microspheres and the required analyticalsophistication, such resolution is only cost-effective at pilot scale.In contrast, RWT proved a practical full-scale viral surrogate forRO, and to a lesser extent, NF system integrity. RWT is inexpensive,easy to dose, and can accurately measure ~4 log removal ata feed concentration of <2 mg/L.The study also found that quality assurance/quality control(QA/QC) measures currently used by manufacturers are insufficientand that membranes passing normal QA/QC tests varywidely in their viral removal ability. However, membrane imperfectionsthat allow significant virus passage can be "healed" throughfouling from normal operation. This operational benefit should beconsidered by regulators when granting log-removal credits formembranes. Includes 13 references, tables, figures.

Related Products

AWWA WQTC57100

AWWA WQTC57100

Adaptation of Method 1622 for Cryptosporidium for Analysis of Wastewater..

$12.00 $24.00

AWWA C203-15

AWWA C203-15

Coal-Tar Protective Coatings and Linings for Steel Water Pipe..

$41.00 $81.00

AWWA C512-15

AWWA C512-15

Air Release, Air/Vacuum, and Combination Air Valves for Waterwork and Wastewater Service..

$41.00 $81.00

AWWA 51637

AWWA 51637

New Customer Data Management System Will Improve Service to BIG Customers..

$12.00 $24.00