Pumice filtration of flocculated pond 1 effluent

The use of Poly ferric sulfate(PFS) flocculation, followed by pumice filtration, reduced the levels of resin acids, colour and 5 Day biochemical oxygen demand (BOD₅) in pond 1 water by more than 90% and appears to at least as effective as the existing secondary treatment system. This Observation indicate that primary flocculation/filtration technology could be as least as efficient as the existing secondary system process for resin acid, 5 Day biochemical oxygen demand (BOD₅) and turbidity removal and more effective for colour removal. Preliminary cost estimates also indicate its probable cost effectiveness; this could be improved by the possibility of recovery or partial recovery and reuse of the flocculating agent.