Anglian water is investing nearly £150 million between 2005 and 2010 increasing our ability to treat and manage our biosolids; a by product of the wastewater treatment process. At Kings Lynn we are investing £27.5 million.
Much of this investment has been focussed on thermal hydrolysis processes. The process breaks down the biosolids, reducing the volume by about 40 per cent, and produces biogas which we use to generate electricity so we don’t have to buy as much. Because the volume of biosolids remaining is reduced we have less to dispose of which means less product to transport by road.
This process therefore reduces our costs and has a beneficial impact on the environment.
At Anglian Water we collect and treat wastewater from 5.5 million customers. The treatment process removes solids such as grit, fats, oils, greases and rag and then a biological and/or chemical process treats the wastewater so that the treated water can be returned to the environment within consent limits set by the Environment Agency.
The residual solids, known as sludge, can be used or disposed in a number of different ways, but generally all of these involve transporting the sludge by road in tankers.
The biosolids process is environmentally friendly compared to traditional methods. It breaks down the solids producing biogas. We use the biogas to generate electricity which is used to power part or all of the treatment process. In some cases we can even sell some electricity back to the grid. The graphic below demonstrates how the benefits of the hydrolysis process (in green) are achieved compared to a more traditional solution (shown in blue).