CENTRA-FLO™
Westerly WWTP, MA - Phosphorus Removal
| Equipment: | Centra-flo™ Gravity Sand Filter with Blue PRO® Six (6) Model CF-200 |
System Size: |
4.15 MGD average flow, 11.62 MGD peak hour flow |
Deliverable: |
70 ppb total phosphorus |
Location: |
Westerly WWTP, Marlborough, Massachusetts |
Background
Blue PRO® was chosen for the
Westerly Wastewater Treatment Facility in Marlborough, Massachusetts after a
competitive pilot project with two other technologies. The Blue PRO®
tertiary reactive filtration system consists of continuous backwash, upflow filters
with hydrous ferric oxide (HFO) coated media for
adsorption of phosphorus. The Blue PRO® system was selected for the
project based on ease of operation, phosphorus results, capital affordability, and
minimized O&M expense. The Westerly facility needs to meet a mass-based permit
of 0.07 mg/L total phosphorus, and may need to achieve lower concentrations in the
future.
System Design
The single-pass Blue PRO® system features six CF-200 quads. The
filters are arranged so that half the filter cells may be operated in series
part-time if lower levels of phosphorus are required. The client plans on
installing a complete second-stage Blue PRO® train should phosphorus
limitations become even more stringent in the future.
Results
An extensive 30-day system performance test was completed in February, 2012. During
this test period with the plant operating within Blue Water’s design, residual
total phosphorus in 24-hour composite samples averaged 0.044 mg/L. Single samples
measured as low as 0.026 mg/L. Ortho phosphorus was never measured above 0.007
mg/L for the entire performance test.
Blue PRO® incorporates modular and fully accessible filtration cells