Determining UF hollow fiber membrane integrity with novel microbial monitoring method

“This study presents the Natural Virus (NV) method, a novel approach for monitoring the integrity of ultrafiltration (UF) hollow fiber membranes by quantifying naturally occurring viruses in surface water. The method was applied across laboratory, pilot, and full-scale UF systems to evaluate the impact of fiber integrity on virus removal and provided critical maintenance input for operation. In a laboratory-scale test with a 120-fiber module, a single damaged fiber reduced the removal efficiency from an intact value of LRV 5 to as low as LRV 1, depending on the nature of the damage (fiber breakage or fiber leak), which affected flow rates and permeate concentrations. Pilot-scale tests with an 8” UF module demonstrated the potential for full integrity restoration by re-plugging damaged fibers. At full scale, the NV method exhibited high sensitivity to module integrity, with log removal values (LRVs) ranging from 1.8 to 5. A predictive model, developed based on permeability data and flow dynamics calculations, showed a strong correlation with experimental results, enabling estimation of the number of damaged fibers based on observed LRV. Critical LRV thresholds for maintenance were established: compromised performance (2.9 ≥ LRV >2.3) suggesting consideration of fiber re-plugging, and critical performance (LRV ≤2.3) indicating the need for module replacement. The NV method demonstrated superior sensitivity compared to conventional techniques like turbidity measurements, proving effective at all tested scales.”

(Citation: Gowda, D.V., Harmsen, D.J.H., Koel, S., et. al.- Determining UF hollow fiber membrane integrity with novel microbial monitoring method – Journal of Membrane Science 719(2025)art. no. 123725 – DOI: 10.1016/j.memsci.2025.123725 – (Open Access))