Wet Weather Treatment with ACTIFLO Clarification

The ACTIFLO® process can be used at various stages of wastewater treatment including: enhanced primary treatment, wet weather clarification, high rate secondary clarification and final polishing of solids removal, phosphorus removal and metals removal.

Typical ACTIFLO Performance


CSO and SSO Parallel Treatment with ACTIFLO

During peak wet weather flow conditions, many plants need to divert a portion of the total plant flow around their biological treatment process. To achieve high levels of TSS and particulate BOD removal of these diverted excess flows, the ACTIFLO® process can be installed at the treatment plant or at a satellite facility within the collection system.

The ACTIFLO® process can be fully automated and the process train(s) can sit idle for extended periods of time and still be fully operational within 15 minutes of start-up.


If flow diversion is not an option at a particular site, or the TSS and particulate BOD removal with ACTIFLO® alone are not enough, a biological solids contact tank can be incorporated into the treatment flow path to improve soluble BOD removal through the system.

Return activated sludge (RAS) from the existing clarifiers is combined with the excess flows into a solids contact tank. A targeted mixed liquor suspended solids (MLSS) concentration is maintained in the contact tank to facilitate rapid uptake of soluble biological oxygen demand (BOD) via contact stabilization. Clarification with ACTIFLO® follows, producing exceptional TSS and total BOD removal rates.