A pilot study was conducted from September through mid-November 2003 to assess two
types of dissolved air flotation (DAF) clarification processes, followed by filtration, and
establish design criteria for a proposed water treatment plant in Peekskill, New York. The DAF processes examined during this pilot study were conventional DAF
treatment and proprietary high rate DAF treatment (AquaDAF", licensed by Infilco
Degremont from Rictor Oy, Finland). This paper presents an overview of the pilot study,
including details on the pilot facilities and criteria used to measure the performance of the
process trains, and an evaluation of results.
The conventional DAF process train included in-line static mixing and two-stage
flocculation, followed by dissolved air flotation. The high rate DAF process train
included mechanical mixing and three-stage flocculation, followed by dissolved air
flotation. Following dissolved air flotation, both process trains were connected to a
common set of filters, operated in parallel.
Two loading rates were tested for each DAF process during the pilot study, 6 and 7.5
gpm/sf for conventional DAF and 12 and 16 gpm/sf for high rate DAF. Various filter
loading rates were also tested. Filters with typical depth media configurations were run at
4, 5, and 6 gpm/sf. Filters with deep bed media configurations were run at 6 and 8
gpm/sf.
The pilot data confirmed that both the conventional DAF and high rate DAF processes
would provide high quality finished water (low filtered water turbidity and high particle
removal) while maintaining adequate filter run lengths. Filtered water turbidity was
consistently below 0.1 NTU, log particle removal ranged between 1.1 and 2.8 for
optimized runs, and unit filter run volumes consistently exceeded the pilot goal of 7,500
gal/sf. Additionally, concentrations of iron and manganese in the filtered water were
frequently undetectable and reliably below 0.02 mg/L and TOC removal ranged from
41% - 58%. Includes tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 11 |
| Published : | 11/15/2004 |
