Sewage sells: the hidden value of wastewater

An image showing a silhouette of a man inside a sewer

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An eye-opening visit to a waste water treatment works uncovers the surprising value in sewage. Hayley Bennett reports

Energy recovery is already commonplace at sewage plants in the UK and across Europe, and now water treatment companies are looking seriously at other solutions for making their industry more cost- and carbon-efficient. Materials recovery feeds directly into ideas about the circular economies of the future, but it’s also another way of improving the bottom line. Water company Severn Trent is involved with an EU project that focuses on getting some of the most promising recovery processes into treatment plants on the back of energy-saving technologies. At the Spernal wastewater treatment plant, the company is experimenting with a raft of technologies designed to extract chemical energy and nutrients such as phosphorus and nitrogen, plus, if everything goes well, cellulose, biodegradable plastics and even proteins.