Ballasted Clarification

Ballasted Clarification is an effective alternative process to the traditional approaches such as additional primary and secondary biological treatment or equalization basins. and consisting of a high-rate, physical-chemical clarification process involving the fixing of flocs, or suspended solids, onto ballast (sand) with the aid of a polymer. A combination of a metal-salt coagulant, micro-sand (or sludge recycle), and enhanced clarifier features increase settling velocities by a near factor of 10.

The ballasted flocculation process yields significant benefits, including:

• Relatively small site requirements with a footprint 5 to 15% that of conventional treatment trains (making it attractive to utilities with limited space);
• Rapid startup times for reaching peak efficiency in fewer than 20 minutes (making it suitable for handling storm-induced peak flows in combined and separate sewer systems); and
• A highly clarified effluent in terms of turbidity and total suspended solids (TSS)