AWWA ACE63028

Zone 7 Water Agency's Patterson Pass Water Treatment Plant includes an ultrafiltrationmembrane process train. The pretreatment process consists of ferric chloride coagulation andsolids-contact clarification. The plant has demonstrated its ability to produce high-quality watersince its initial startup in the summer of 2003. However, the cellulose acetate membranes arecurrently deteriorating at an accelerated rate and there are numerous issues that have createdoperational challenges and reduced production capacity. The main issues appeared to beassociated with its pretreatment process. The operation of the pretreatment process ahead ofthe membranes has been challenging due to stringent warranty conditions originally specified bythe membrane manufacturer, particularly the iron level in the feed water, which has most likelycontributed to irrecoverable loss of membrane permeability. Another factor that may have had asignificant impact was the delayed initial clean-in-place cleaning. The membranes alsoexperienced several air/water hammers in 2004 due to problems with controlling the water levelin the clarifier. These issues have resulted in degraded fiber material properties, shrinkingfibers, and broken fibers. Although some of the issues have been resolved, some will requirefurther investigation and mitigation. However, regardless of these issues, the ultrafiltrationmembrane system consistently produced high quality finished water with less than 0.1 NTU ofturbidity. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

06/01/2006

Number of Pages:

17

File Size:

1 file , 2.1 MB