Membrane Fouling – a Case Study

One of the primary operational concerns with any membrane plant is fouling. This becomes even more of a concern at higher recovery and flux rates. A case study at a high recovery municipal installation demonstrates the ill effects of fouling from silica, calcium fluoride, and other foulants, as well as methods to identify and monitor, manage, and remove difficult foulants. A 6.0 MGD high recovery water treatment system was installed at Ft Irwin, CA to provide the facility with potable water and replace the existing antiquated treatment system. The fort is situated in the Mojave desert, and water is scarce. Therefore to preserve the resource, the overall treatment system was designed to achieve a total recovery of over 99.0% water recovery. These high recoveries presented several challenges to the treatment process, including intermittent and rapid fouling of the RO membranes. Through operational practices and membrane autopsy, the foulants were identified as silica and calcium fluoride. Cleaning regimes were developed to successfully remove scale and restore the membranes to near pre-fouled conditions. This case study also underscores the importance of data monitoring of both operating and cleaning data, and data normalization to help identify the presence of multiple foulants concurrently. Established means for data collection and interpretation will also be presented.

This presentation is available to AMTA Members only.