Size a Dissolved Air Flotation (DAF) or Induced Gas Flotation (IGF) cell to polish oily water from 50–200 mg/L down to 5–20 mg/L. Microbubbles attach to oil droplets and float them to a surface skim layer for recovery. DAF dissolves air at pressure then releases at atmospheric (precise control of bubble size); IGF induces bubbles atmospherically (simpler, lower OPEX).
Process Stream
BWPD
mg/L
mg/L
ppm
0 if no polymer; > 5 ppm gives capture boost
Cell Design
gpm/ft²
1–5 typical; lower = larger cell
min
ft/hr
DAF Saturator
(Applies to DAF only)
psig
—
0.5–0.8 typical
%
mg/L
~30 (60°F), ~24 (90°F), ~18 (130°F)
📚 Learn the Theory
A/O ratio derivation, saturator design, DAF vs IGF tradeoffs, polymer coagulant boost.