Gwinnett County, Georgia is expanding an existing water reclamation plant by 40 mgd (maximum
monthly flow). The expansion includes 50 mgd (feed flow) of membrane filtration equipment using
Zenon ZeeWeed ZW500c ultrafiltration membranes, selected after a competitive procurement
process. A four-month pilot test was conducted to verify proposed design and operation criteria while
treating chemically-clarified secondary effluent. Testing was successful and performance met the
manufacturer-guaranteed flux, recovery, transmembrane pressure (TMP) and cleaning frequency.
Short maintenance cleans every 42 hours and periodic recovery cleans (greater than 30 days)
maintained hydraulic performance. Permeate water quality met all treatment goals during the testing.
At times during the test program, iron fouling from excessive ferric chloride feed carrying over from
the clarifier was observed. The iron fouling was controlled by maintenance cleans with citric acid,
instead of normal sodium hypochlorite cleans, and by periodic membrane "relaxation" which
simulates actual operating conditions during backwash valve movement in the full-scale facility.
The full-scale system has been designed and the general construction contract is expected to bid and
be awarded in early 2003. The contract allows for the membrane process facilities to be
commissioned in 25% capacity increments. The first increment of membrane capacity is
expected to be operational in 2005 and the full facility completed in 2006. Includes 4 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 2.6 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 13 |
| Published : | 03/05/2003 |
