Zone 7 Water Agency's Patterson Pass Water Treatment Plant includes an ultrafiltration
membrane process train. The pretreatment process consists of ferric chloride coagulation and
solids-contact clarification. The plant has demonstrated its ability to produce high-quality water
since its initial startup in the summer of 2003. However, the cellulose acetate membranes are
currently deteriorating at an accelerated rate and there are numerous issues that have created
operational challenges and reduced production capacity. The main issues appeared to be
associated with its pretreatment process. The operation of the pretreatment process ahead of
the membranes has been challenging due to stringent warranty conditions originally specified by
the membrane manufacturer, particularly the iron level in the feed water, which has most likely
contributed to irrecoverable loss of membrane permeability. Another factor that may have had a
significant impact was the delayed initial clean-in-place cleaning. The membranes also
experienced several air/water hammers in 2004 due to problems with controlling the water level
in the clarifier. These issues have resulted in degraded fiber material properties, shrinking
fibers, and broken fibers. Although some of the issues have been resolved, some will require
further investigation and mitigation. However, regardless of these issues, the ultrafiltration
membrane system consistently produced high quality finished water with less than 0.1 NTU of
turbidity. Includes tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 2.1 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 17 |
| Published : | 06/01/2006 |
