ACWA Services (UK) has completed the design and installation of a NITREATTM Nitrate Removal plant for the Keldgate Water treatment works of Yorkshire Water – part of a £5.4m project being constructed by the main contractor, civil engineering company, Mott MacDonald Bentley. The new project, which is the largest installation of its kind in the UK, is scheduled for commissioning by the end of 2009.
ACWA’s innovative NITREATTM technology is already operating successfully in the Thames and Anglian Water regions where, in addition to removing nitrates from water, it is providing a number of operational advantages. The system makes more effective use of resin, provides low levels of waste and eliminates process downtime for regeneration, whilst maintaining consistent effluent characteristics. Site performance tests have proved the effectiveness of the system to produce waste volumes of less than 0.5% of total works output, which is a significant advantage of the process design.
The counter-current ion exchange system is an improvement on conventional ‘batch’ systems, as exhausted ion resin is continuously taken off-line, backwashed, regenerated, rinsed and returned to absorption, with all phases of the cycle occurring concurrently.
The process design will allow water at 33 million litres/day of water from the 90 million litres/day WTW, to pass through the nitrate removal system. After reducing nitrate levels to fewer than five parts per million, the treated water will be blended back into the main flow to produce water for public consumption at 42mg/litre – well within the limits for drinking water quality and future proofing the Yorkshire Water system against anticipated rises in nitrate levels.