Viltra's bespoke sewage treatment systems use a 3-stage biological process to provide a very efficient, reliable and cost-effective solution to sewage disposal. They are customisable and can be adapted for any non-standard residential, commercial or industrial applications where there is no access to a main sewer.
✓ Non-mechanical recirculation
✓ Flat, flush ground-level access covers
✓ Concrete or lightweight plastic systems available
✓ Failure alarm systems included as standard
✓ No mechanical or electrical parts within unit
✓ Process is Tested and Certified to EN12566-3 European Standards
How it works
• The primary settlement tank (PST) is a two-stage tank designed to maximize the removal of gross and suspended solids. The PST also has a sludge storage facility incorporated depending on desludge periods
• The biological treatment phase incorporates two proven principles of biological process in the form of a fixed film reactor and a suspended floc dispersed growth system for high transfer rates and operational control, achieving a stable treatment process unaffected by shock loads.
• The heart of the process is a submerged, high-rate, plastic media on which a fixed film of biomass is grown. The film consumes incoming settled effluent, and oxygen is provided by a small blower. The media is aerated through HDPE membrane diffusers that provide fine bubble aeration.
• The fine bubble aeration is carefully controlled providing optimum oxygen transfer rates and scouring to slough off excess biomass, keeping the thickness of the fixed biological film at optimum levels.
• The fact that the media remains submerged means that there will be biomass which is “unfixed” to the media but achieves treatment through suspended aeration.
• The final settlement tank is designed to provide maximum settlement of any suspended solids prior to discharge. The system incorporates continuous sludge return airlift to return sludge from the final settlement tank back to the primary settlement tank.
• This system also provides for continuous recycling of treated effluent back to the PST to not only provide dilution of incoming settled effluent, but also to ensure continuous flow during periods of low or no flow, thereby keeping the biomass in prime condition.