One of the innovations being trialled in Anglian Water‘s Innovation Shop Window is a new mobile sludge thickener which should drive cost and carbon out of the company’s water recycling operation.
The game-changing kit is housed in a trailer, which can be towed to water recycling centres where it is used to thicken sludge by removing water.
Large amounts of sludge are currently moved by tanker from smaller water recycling centres to larger sites that have sludge thickening equipment. Using the trailer to take the thickener to the sludge instead could see a huge reduction in tanker movements. Sludge from Newmarket is currently sent to King’s Lynn, using between 10 and 15 tankers a week.
Reducing the volume of sludge transported saves money and helps meet sustainability targets. It is not cost effective to install permanent thickening equipment on smaller and medium-sized sites, so the mobile thickener provides a good solution.
The cost savings for the Newmarket Water Recycling Centre and surrounding sites are around £150,000 per year, and another five areas have already been identified with similar levels of savings. Carbon emissions from transporting the sludge in tankers are forecasted to be down by 50 per cent as a result of the project.
As well as being mobile, the thickener uses a new method that uses air to break up chemical bonds in the sludge before a polymer is added and binds it together. The sludge then goes into a rotating drum, similar to a colander, which removes any water.
With its water content reduced, the sludge is then easier to transport for use in agriculture. It reduces the volume of water in the sludge by 50 per cent.
The current output is 2.7 per cent dry solids and the early tests with this method show that dry solids are up to about 5.3 per cent.
By using the mobile sludge thickener, Anglian Water is reducing both tanker usage and its carbon footprint.