COVENTRY, England - Utility Severn Trent has awarded Veolia Water Technologies a contract to provide Moving Bed Biofilm Reactor (MBBR) technology.
The technology will be used to help upgrade the treatment process at Little Aston WastewaterTreatment Plant (WWTP) to meet tighter ammonia discharge consent of 1 mg/l.
Severn Trent Water and Mott Macdonald Bentley, its Tier 1 delivery partner, were considering a number of options including replacing the existing trickle filters, which presented significant budget challenges.
It was decided that as the existing trickle filters were in good condition with “a suitable asset life”, the MBBR technology would be fitted as a tertiary treatment option.
The proprietary design of the MBBR carriers ensures that a “high protected surface area is provided for the development of biofilm, enabling high treatment capacity in a very small footprint”, according to Veolia Water Technologies.
On their protected surfaces, different micro-organisms ranging from bacteria to ciliates and rotifers are established in a biofilm. These carriers are kept in motion either by the air injection in aerobic systems or by mixers in anoxic or anaerobic systems.
The continuous motion promotes exchanges between wastewater and biofilm, allowing pollutants to be degraded to meet effluent quality requirements, the company added.
During the procurement process, process engineering and operations teams visited another site, Cudworth WWTP, to see the MBBR technology in action.
The Little Aston WWTP project will be the fifth Severn Trent Water site to use Veolia’s MBBR technology.