Operation & monitoring of pilot scale BNR plants


Severn Trent Water Ltd


Nov ’04 to Jun ‘08

Increasingly stringent legislation and tightening consents have reduced the discharge limit for phosphorus from sewage treatment works. Environmental and economical issues with chemical dosing have forced the investigation into biological nutrient removal (BNR).

To date four BNR pilot plants have been operated on behalf of Severn Trent Water since 2003, for durations of between 3 to 18 months. Severn Trent has benefited from this work in maintaining their position as UK Water Sector leaders in the field of biological nutrient removal.

Different configurations for the BNR process have been evaluated within tight timescales to allow for the project management team from STW to make decisions which impact on engineering designs considered for construction. This has directly minimised abortive spend, confirmed design aspects which account for site constraints e.g. conversion of ASP 1-6 at Minworth to a modified UCT design, which has the cheapest whole life cost, lower footprint and engineering is easier, with minimal process interference.