HOW SEWAGE SLUDGE IS DEALT WITH TODAY: A WASTE OF RESOURCES!
The Swedish sewage treatment plants produce about one million tonnes of sludge every year. This sludge contains a large amount of phosphorus, nitrogen and potassium – all of which are important plant nutrients. If all sludge was used as fertiliser, up to 7,000 tonnes of phosphorus and 9,000 tonnes of nitrogen could be added to arable land each year. However, only a small part of the sludge, about a quarter, is currently being recycled. This is because the sludge contains a number of undesirable substances, including heavy metals, drugs, viruses and bacteria.