The DynaSand® D2 filtration system achieves enhanced effluent quality by providing a two-stage filtration system when targeting water quality, originally thought only possible via membrane filtration. This provides proven performance and reliability for:
- RO pretreatment (SDI < 3)
- Ultra-low phosphorus (< 0.02 mg/l)
The system is based on a modular design where each module consists of two continuous self-cleaning DynaSand® filters. The first stage filter uses larger sand grain size to give it more solids-handling capacity and employs the DynaSand® CCF process known as continuous contract filtration. In this process, coagulation and separation take place within the filter bed and produce a very high-quality filtrate.
The second filter acts as a polishing filter, using smaller sand size and provides higher removal efficiencies. The third component of the D2® system is a Lamella® Gravity Settler which treats reject from both filters to reduce reject rate to 0.5% of the forward flow.