United Utilities - Enzymic Hydrolysis

The treatment and disposal of wastewater sludge presents a major challenge to society and to the water industry. Rising sludge production coupled with more demanding environmental standards place large demands on the water industry’s existing treatment assets.
 
Developed in-house at United Utilities by a team of 8 scientists and engineers, High Rate Enzymic Hydrolysis makes wastewater sludge safer for use as a fertilizer and generates up to 40% more renewable energy in the form of biogas.
 
In 2001 the United Utilities Board approved expenditure of £1 million to build the first full-scale demonstration plant.  This plant met all the expected outcomes and also showed how the process could achieve significantly increased biogas production that could be used to generate electricity. The process has exceeded the design expectations and United Utilities has built four plants in total.
 
By harnessing nature in this way United Utilities has identified a solution that can  readily be retro-fitted to enhance the performance of existing assets and not only meet, but significantly exceed, new and all anticipated sludge quality  obligations. The process is over three times faster than conventional digestion.