Coagulation & Flocculation Ahead of the Plate Settler
Turning Fine Colloids into Settleable Floc
Chemical conditioning is the single most important upstream step for plate settler performance. Well-formed floc settles fast; poorly conditioned water passes straight through.
Many suspended and colloidal particles are too small and too stable to settle on their own. Coagulation neutralizes their surface charge with metal salts (alum, ferric chloride, PACl) or an organic coagulant, allowing particles to come together. Flocculation then gently mixes the water so destabilized particles collide and grow into larger, denser flocs.
The plate settler removes these flocs efficiently — but only if they are properly formed. Rapid mix energy, coagulant dose, flocculation time (typically 10–20 minutes at a tapered G-value), and pH all determine floc quality and therefore effluent clarity.
R+F integrates coagulation and flocculation as part of the packaged system, sized to your water chemistry and validated by jar tests or a pilot trial.
Engineering Considerations
Coagulant Selection
Alum, ferric, or PACl selected by jar test for your specific water chemistry and target parameter (TSS, turbidity, phosphorus).
Flocculation Time
Tapered gentle mixing, typically 10–20 min, to grow dense floc without shearing it apart.
pH Control
Each coagulant has an optimal pH window; dosing and pH adjustment are coordinated for best results.
Polymer Aid
A flocculant polymer can be added to build larger, faster-settling floc and sharpen effluent quality.
Request an Engineering Assessment
Our engineers will review your application, flow rates, and water quality data to recommend the optimal plate settler configuration.