Client: Laois County Council
Location: Co. Laois, Ireland
Project Value: €11.5m
Description: Design, build, operation and maintenance contract for a bundle of 5 Wastewater Treatment Works in County Laois
W&B designed, built and now currently operate this bundle of WWTW’s in County Laois, comprising;
The contract gave Ward & Burke the opportunity to propose the “Stahler” Technology as an alternative aeration system as it had a huge saving on the energy consumption over the 20 year Operation and Maintenance period with considerably less sludge to treat and dispose, while also reducing our onsite programme and cost as well as our carbon footprint.
The Stahler system as an alternative innovative product to diffused aeration. It is installed in a conventional activated sludge system with activated sludge in the mixed liquor and a return sludge circuit between the aeration and FST. The Stahler Wheel is used for aeration and mixing of the tank, which replaces a diffused aeration system and mixer in a conventional system.
The system also contains a fixed film element of treatment due to the specific construction of the media discs on the aerator pipes in the wheel. Therefore this system is a true hybrid system of activated sludge and fixed film in which the activated sludge dominates. For this reason, the system can operate at higher efficiencies than conventional activated sludge processes resulting in lower power consumption.
The wheels are manufactured in segments in our offsite facilities and assembled quickly onsite to avoid disturbances and reduce the overall cost and time required.
The basic construction of the wheel is a central shaft and a steel cage structure which transfers the forces directly to the bearings and thus the central shaft is significantly less stressed.
The pipes are formed by joining discs into cylinders, with pipes specially arranged to create the Stahler Wheel.