In response to increasing demands for potable water in southern California, the
Orange County Water District and Sanitation District of Fountain Valley,
California, have developed a joint Groundwater Replenishment (GWR) System. This
project will treat secondary wastewater effluent, currently discharged to the
ocean, to produce high quality water for recharge of the Orange County
groundwater basin and injection into a sea water intrusion barrier. The
three-phase project, beginning in 2003, will ultimately produce 100,000 acre-feet
per year by 2020. Phase 1 of the GWR project, with a capacity of about 80 million
gallons per day (mgd), has been conceptualized and the preliminary design has
begun. Phase 1 adopts the add-on approach. Microfiltration (MF), followed by
reverse osmosis (RO), is to be added on to the end of the secondary treatment
process to produce high-quality water for reuse. Phases 2 and 3 of the GWR system
project, however, present a number of different challenges including a shortage
of land, high costs associated with additional secondary wastewater treatment
facilities, and the disposal of additional biosolids. A new treatment approach
that utilizes membrane processes in combination with anaerobic biological
treatment could alleviate such problems. The proposed approach utilizes the MF
process to treat primary effluent followed by reverse osmosis (RO), or
nanofiltration (NF), to concentrate soluble biological oxygen demand (BOD) and
produce a high quality effluent for reuse. The RO concentrate, which is free of
suspended material, is then treated in a high-rate anaerobic digestion process
that eliminates the need for conventional secondary activated sludge treatment.
This paper presents details of the process as well as preliminary pilot plant
results from continuous testing of the new treatment approach at Orange County. Includes 7 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 530 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 13 |
| Published : | 01/01/2000 |
