The KEE Process NuDisc® is a totally self-contained, covered, single piece packaged treatment system for onsite wastewater treatment. The KEE NuDisc and NuDisc-R are innovative and truly versatile systems for the effective treatment of wastewater, including Nutrient removal. They can be configured for BOD reduction, suspended solids reduction, Ammoniacal and/or total Nitrogen reduction and Phosphorus reduction. New optional features have been built into the NuDisc Single Packaged Plant to create the New KEE NuDisc-R Packaged Plant System - physical-biological tertiary treatment with water recycling.

Central to the operation of each NuDisc system is the Rotating Biological Contactor (RBC). This stage is divided into two specific zones: anoxic reactor and aerobic reactor. The KEE NuDisc system, includes the primary settlement tank, the RBC and the final settlement tank, which are housed in a single GRP tank and arranged in such a way that flow attenuation becomes an integral part of every plant.

SP6                 KEE-NuDisc RBC Technology   KEE NuDisc RBC Technology


NOTE: KEE now offer a Lifetime Warranty on all NuDisc®, new installs with an ‘Elite’ KEE services and Maintenance contract.

KEE NuDisc-R

The Versatile Packaged Treatment System

The first ever advanced wastewater treatment plant with built-in Tertiary filter and UV disinfection system.

The KEE NuDisc-R is a new system utilising the KEE NuDisc well-proven principle of attached growth rotating biological contactors (RBC), which support an active film (biomass) for biological treatment of the wastewater. The RBC stage is divided into two specific zones, the first acting as an anoxic reactor and the second as an aerobic reactor. The whole system, including the primary settlement tank, the RBC and the final settlement tank, are housed in a single GRP tank and arranged in such a way that flow attenuation becomes an integral part of every plant.


At the first stage of the treatment process, the wastewater enters the primary settlement tank. Here the solids are settled out and retained as sludge, which is drawn off periodically for disposal. The partially clarified liquor is then brought in contact with the anoxic stage of the RBC reactor where partial degradation of BOD and de-nitrification take place. The biomass in the anoxic stage also provides biological attenuation of organic pollutants, which are partially treated and degraded into much more readily treatable substrates for the aerobic RBC stage.

The downstream aerobic RBC stage is operated under plug flow conditions where BOD removal and nitrification take place. The KEE NuDisc technology can be applied to different applications to achieve the desired final effluent quality. For instance, where phosphorous removal is required this is achieved by coagulating phosphorous out of the treated effluent at the end of the RBC stage.

The final clarifier is benched at the bottom to facilitate the consolidation of sludge which is then returned to the primary clarifier through the pump assisted hydrostatic sludge return system. In applications requiring de-nitrification, this is achieved by further treating the nitrified effluent in the anoxic zone of the treatment system.

Built-in Optional Tertiary Treatment

The treated effluent from the final clarifier can be discharged to a watercourse or, as an option, this can be further treated to a much higher quality in a physical-biological tertiary stage.  This physical-biological filter includes media with extremely large surface area to volume ratio and is arranged in the unit to work as alternating aerobic and anoxic zones for the most effective breakdown of the residual organic constituents (hard BOD) of the treated wastewater from the first and second stage RBC process. The tertiary filter stage is fitted with natural wind turbine or electric fan assisted aeration zones for creating the alternating aerobic-anoxic stages in the filter. The tertiary stage media structure is such that the effluent undergoes breakdown of the remaining soluble organic material and the fine solids contained in the wastewater. The fine organic solids are captured and retained in the media for breakdown. 

Effluent Disinfection

The treated effluent from the compact NuDisc or NuDisc-R can be disinfected using packaged UV light disinfection system before discharge. The disinfected effluent can be either discharged to a watercourse or recycled for irrigation or other applications such as toilet flushing or non-portable use.

The KEE NuDisc is offered for flows from 1m³/day through to 70m³/day and is normally packaged into a single piece structure with low profile  aesthetically acceptable sectional GRP covers. They incorporate hatches that allow easy desludging and access to mechanical components for regular maintenance. This same NuDisc technology is also available as a Modular RBC System, where the individual unit process operations are separated to provide greater flexibility in design for the treatment of larger flow rates, whilst retaining the essential design features such as Managed Flow and flow/load attenuation.

The KEE NuDisc and KEE NuDisc-R is fabricated in lightweight, corrosion-resistant and tough Glass fibre Reinforced Polyester (GRP), it is virtually silent and odour free.

The KEE NuDisc is simple to install, with minimal site work and is suitable for small to medium flows of up to 70m³/day in single-piece configuration.

Extremely low power demand and low maintenance costs, together with longevity ensure the lowest lifetime cost. Structural components have a 30-year design life and mechanical/electrical components are selected for 100,000 hour L10 life.

KEE fixed price operation and maintenance contracts are available.

and The KEE NuDisc is available for RENTAL.