They’re both fairly unappealing and just a bit whiffy: thick, toxic algal blooms that increasingly clog Scotland’s lochs and rivers and smelly mountains of sewage sludge.

But now researchers are looking into turning human waste from the sewage system into a mineral-rich material that could be used to both attack the scourge of algal blooms and help tackle another environmental headache.

Scottish teams are exploring how biochar created from human waste that’s been burned at high temperature can be used as a water filter capable of removing large amounts of phosphorus which, when present in excess quantities, contributes to algal blooms.