Severn Trent poised to begin construction of bug-based treatment technology

Severn Trent is poised to begin construction a full-scale demonstration test-bed site at Spernal STW in Redditch using a water treatment technology that harnesses the capacity for cultivated bacteria to break down the organic pollutants in wastewater to produce biogas for use as a renewable fuel source.

The process to be deployed in the test bed uses a bioreactor – bacteria held in a sludge blanket under anaerobic (oxygen-free) conditions – to digest wastewater components producing biogas (methane). The effluent is then filtered to take out the solid waste and to remove biogas for use in generators, boilers and so on.

Pete Vale, technical lead on the project, said: “Our test-bed offers us the exciting opportunity to evaluate energy-neutral wastewater treatment and to recover valuable materials contained in wastewater such as fertilisers, bio-plastics and cellulose. That will drive revenues, by selling back to industry and ultimately cost savings for our customers."

The anaerobic membrane bioreactor (AMBR) technology that will be used is established in warm climates. Severn Trent will be using recently developed AMBR which operates in colder ambient temperatures in what it claims will be "the first full scale AnMBR system in Europe.”

The test bed secured grant £453,000 worth of funding from the European Union’s Horizon 2020 Innovation Fund as part of Severn Trent's four-year NexGen wastewater treatment programme which includes 30 "world-leading" European partners. The programme is seeking to "evaluate and champion circular economy solutions and systems in the water sector," according to external funding lead for Severn Trent, Paul Knuckle.