Non-invasive measurement of membrane scaling and cleaning in spiral-wound reverse osmosis modules by ultrasonic time-domain reflectometry with sound intensity calculation

Gypsum scaling and membrane integrity of osmotically driven membranes: The effect of membrane materials and operating conditions

“…In our previous study on FO particulate fouling, we observed preferential particle accumulation under the spacer filaments [31]. The current observation is also consistent with the existing RO scaling literature that the crystal formation and precipitate deposition occurred preferentially at the spacer induced hydrodynamic dead zones [32][33][34][35]. For the case of CTA, its favorable surface properties (no binding sites for calcium and smooth surface) do not allow the initiation of severe scaling and thus cause little damage to membrane structure.…”

Design and test of a reverse osmosis pressure cell for in-situ small-angle neutron scattering studies

“…Greenberg and coworkers developed the ultrasonic time-domain reflectometry (UTDR), where the membrane surface is monitored by sensing the reflection of ultrasonic radiation from the membrane [19]. The UTDR was proved efficient in studying membrane characteristics, as well as monitoring membrane fouling and biofouling [20,21]. However the detection of biofilm and scaling on membrane surfaces is still a significant challenge for UTDR due to the small difference in acoustic properties at the fouling/membrane and fouling/feed solution interfaces [20].…”

In-situ monitoring techniques for membrane fouling and local filtration characteristics in hollow fiber membrane processes: A critical review

“…With the integration of monitoring technique, such as non-invasive UTDR, DO technique or EIS etc., the side-stream cell is capable to provide an effective early warning of membrane fouling. This strategy has been successfully used to monitor fouling and cleaning of the reverse osmosis spiral wound module [98][99]. It confirmed that the side-stream cell coupled with UTDR could monitor membrane fouling and cleaning in a commercial spiral wound module.…”