The Tuke & Bell Robette consists of a G.R.P. tank which is separated into a number of different treatment zones. In the Primary Settlement Zone settles gross solids into sludge, the supernatant liquor then passes forwards into the Biozone. In the Biozone, slowly rotating contactor disks treat the effluent by means of biological oxidation, the treated liquid then flows into the Final Settlement Zone. In the Final Settlement Zone any humus sludge or scum that forms as part of the natural biological process is removed by means of an automated recirculation pump system and returned to the Primary Settlement Zone for further treatment. The final effluent is then typically discharged to a reed bed or water course depending on local environmental allowances. The unit is entirely enclosed by low profile covers; these contain any odours, guard the moving components and give a very low visual impact to the plant.
The Robette is based on the design of the larger RoBeC unit and is offered in a range of standard population sizes from 25 up to 125; multiple units can be installed on a single site to increase maximum capacity. The design principles are the same as the larger unit, however due to the smaller size and simplification the cost is vastly reduced.
Tuke & Bell has over 30 years experience with rotating biological contactors and developed its Robette unit to cater for smaller private sites where access to mains sewerage is not possible. Typically small independent building companies will specify the Robette unit; additionally many UK water authorities are now adopting Robette units for use in small isolated sewage treatment works.
The Tuke & Bell Robette incorporates the following features: –
- Self contained package sewage treatment plant.
- Very low running costs and maintenance requirements.
- Automated design requires minimal operator input.
- Small unit footprint allows for simplified construction.
- Low visual and environmental impact.