Fiber breakage continues to be a problem for low-pressure membrane systems in drinking water plants. Not only do membrane integrity issues increase the risk of pathogens in the potable water supply, but integrity test failures mean less capacity, solids in the backwash water – which could cause irreversible fouling – and higher disinfection costs. In addition, repairing the fiber breaks requires a considerable amount of time and money, with some plants paying over 20% of the equipment cost to make the repairs needed during the plant’s 20-year life [Freeman, 2012]. Many plants have created a “pinning station” to make the repairs, some even hiring a person whose sole job is to pin fibers! To combat this problem, one manufacturer – inge, now part of Dupont – developed a fiber containing seven feed channels arranged in a honeycomb-like structure, which gives the fiber strength that single-bore fibers lack. This membrane is now used in over 250 installations, including several facilities in the U.S. This presentation looks at five of those installations, ranging from 0.15 to 3.75 million gallons per day (MGD). These plants had several things in common: they all had single-bore membranes that they were pinning frequently, treated surface water (or groundwater under the influence), and they were able to convince their states to accept the new membranes by operating them in parallel with their existing systems. As a result, one site elected to replace their entire membrane trains, while the other facilities were able to retrofit the new membrane modules onto their existing membrane skids. This paper details the existing systems and their integrity issues and defines how the selected membrane has been able to resolve those issues, meet the USEPA’s Long Term 2
This presentation is available to AMTA Members only.
- David Holland
- Aqua-Aerobic Systems, Inc.
- AMTA/AWWA Membrane Technology Conference, Las Vegas
- AMTA/AWWA Membrane Technology Conference
- No-Break Fiber, Backwash Water, potable water supply