Activated Sludge domestic wastewater treatment systems
These sewage systems recycle their own waste products along with live, settled, beneficial bacteria back to the digestion chamber to activate and speed up the digestion of the raw sewage.
They don't need any extra bacteria adding during their lifetime as they constantly 'top-up' the digestion chamber with active bacterial sludge from the final settlement chamber.
They are a simple, reliable wastewater treatment solution and tend to be cheaper than 3 stage plants, with a similar low electricity cost.
Only the Vortex ASP is adjustable, up or down, for different numbers of people using it.
These biological sewage treatment plants try to digest the gross solids and liquids together in the central compartment via air injection.
The sewage is aerated for a longer period of time than with a three stage plant, hence the name, 'extended aeration'.
There is no 'larder' as with an APEX three stage plant, so 'Feast and Famine' restricts their application for most activated sludge plants. However, the Vortex activated sludge sewage treatment system, has overcome this problem by incorporating an air regulator valve to 'turn them down' for low populations and turn it into a 'smaller' plant.
The effluent can be discharged into a soakaway drainfield, or a watercourse, subject to the necessary consents
Servicing of most of these treatment plants is 6 monthly (the Vortex is 12 monthly) and the plants need emptying about every 1 to 2 years, (depending on how many persons are using them), to remove sludge.
The first extended aeration plants were brought into the UK from America in the mid 1990's. It was said at the time by the original importer, that they did not cope very well with underloading situations, but this information seems to be no longer passed on to the customer. All, apart from the Vortex, work better when reasonably loaded.
Electrical consumption of most plants tends to be higher than that of three stage sewage treatment plants, due to the longer aeration time needed by the process. However, the Vortex sewage treatment plant uses less than most three stage plants, due to its design. A 6 person Vortex only uses 40 watts/hour.
Click here for How the VORTEX™ is so energy-efficient.