The Cities of Albany and Millersburg, Oregon operate a Joint Water Treatment
Plant which went on-line in November 2005, using immersed membranes to treat
water from the Santiam River at a capacity of 16.5 mgd. The City of Albany
operates a conventional plant treating water from a canal diversion off the same
source. The first round of quarterly disinfection byproduct (DBP) sampling
conducted after the new plant went on-line showed elevated levels of haloacetic
acids. In response to the DBP results, the Cities evaluated the use of in-line
addition (no flocculation or settling provided) of a nominal dose (5 mg/L) of
aluminum chlorohydrate (ACH) as a means of reducing DBP precursors ahead of
the free chlorine disinfection process employed at the new plant. Full-scale
testing of ACH addition was combined with bench-scale simulated distribution
system (SDS) DBP testing of plant finished water to document the reduction of
DBPs through the ACH addition. Testing confirmed that a 5 mg/L dose of ACH
could significantly reduce HAA concentration under SDS conditions, and that
monitoring raw water turbidity and chlorine demand through the plant are
excellent indicators of when the coagulant dose needs to be adjusted due to
changes in source water quality. Coagulant testing was performed in conjunction
with performance testing of the membrane filtration system, whereby one cell of
the system was operated for several 30-day test periods under controlled
conditions to simulate future plant capacity requirements. The membrane
system performance testing showed minimal impact on membrane fouling rates
due to the ACH addition. Includes tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 3.1 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 19 |
| Published : | 03/01/2007 |
