Civil Engineering Reference
In-Depth Information
TABLE 15-10. Nanofiltration Membrane and System Characteristics for PBCWUD
Treatment Plant No. 3
Membrane molecular weight cutoff*
200 daltons
Active membrane area
400 sq ft per element
Average permeate flux
15 gfd
Maximum transmembrane pressure
120 psi
Membrane type
Thin-film composite
Membrane materials*
Active layer
Cross-linked aromatic polyamide
Support
Polysulfone
Substrate
Polyester fabric
No. of membrane treatment trains
4
Stages of filtration per train
2
First stage vessels per train
35
Second stage vessels per train
21
Total vessels per train
56
Membrane elements per vessel
7
Membrane element diameter
8 inches
Membrane element length
40 inches
Membrane manufacturer*
Fluid Systems (TFCS8929ULP)
* From reference 28.
Riverside, California
The Arlington Desalter in Riverside, California, is owned and
operated by the Santa Ana Watershed Project Authority. The RO system treats ground-
water that has been degraded through over 100 years of irrigated agriculture that
resulted in increased salt and nitrate concentrations, leaving the water unfit for do-
mestic use. The following summary outlines operating characteristics of the system:
Start-up: 1990
•
Capacity: 4.0 mgd product water
•
Recovery: 76 percent
•
Typical operating pressure: 200 psi
•
Membrane type: thin film composite
•
Brine disposal to nonreclaimable waste line that discharges to a regional waste-
water treatment plant
•
The following water quality data summary is from the plant after 10 years of
operation with the original membranes that are still in service:
Concentration, mg / L
Feed
Constituent
Permeate
TDS
1,130
76
Total alkalinity as CaCO
3
317
18
Total hardness as CaCO
3
541
15
Chloride
175
10
Nitrate nitrogen
18
3
