• First Wastewater Treatment Plant based on Biological Nutrient Removal Technology supplied by Copa Ltd in the UK
• Works with a stringent ammonia consent

Project Need :

Upgrade of the existing treatment works to achieve a higher quality of final effluent as the works has a stringent ammonia consent.

Description of Works:

Screened sewage will be pumped to the Aerobic/Anoxic Tank (AAT) on demand during normal dry weather flow conditions. During wet weather flows or when the inflow exceeds 3 x DWF the pumps will direct the flow to the inlet of the Intermittently Operated Clarifier (IOC). The operation of the AAT will be such that it will swing between aerobic and anoxic conditions to optimise the nitrification and denitrification process. Typical times for aerate and non aerate conditions will be correlated in the PLC with the actual diurnal dry weather flow pattern into the plant .

During the non-aerate period the aerators turn on for about 3 minutes every 15 minutes to ensure the microorganisms are in intimate contact with the nitrates to maximise denitrification. Mixed liquor flows into the IOC and a high flow rate RAS pump returns mixed liquor from the IOC to the AAT during the aeration period only in the IOC.

In the IOC the process undergoes a cycle of aerate, settle and discharge. During the aerate period the aerators turn on and off in a similar manner to the operation of the aerators in the AAT to ensure the optimisation of the nitrification and denitrification process. When the level reaches a certain level the IOC goes into a dedicated settle phase and after a preset time the clear effluent is discharged off the top of the tank using the GLS submerged weir. At the end of the discharge the aeration period starts again and the RAS pumps turn on.

Waste Activated Sludge (WAS) will be thickened in a DAF and transferred to a sludge holding tank. Underflow from the DAF will be directed back to the head of the plant.

Key Elements;

• Civil build and mechanical installation of Hybrid BNR process consisting of 2 x Aerobic Anoxic Tanks (AAT) and 2 x Intermittently Operated Clarifiers (IOC)
• Return Activated Sludge Pump provided for the return of MLSS from the IOC to AAT.
• Waste Activated Sludge Pump provided to pump MLSS from the IOC to the sludge storage tank.
• Gas Locked Syphon Submerged weir provided in the IAT.
• Design and Project Management services to ensure equipment and process integration into main works MCC
• Trace heating and lagging to pipe works
• Steelwork: walkways, access stairs, hand ladders, etc
• Site testing & Commissioning
• Staff Training