Algae water treatment under test has promise for cheaper, greener wastewater cleaning

Replacing chemical treatments with algae farming could make wastewater treatment cheaper and more sustainable, according to researchers at Bath University who are testing the method in partnership with Wessex water. The method is particularly suited to removing phosphorus from sewage, an increasing problem for water treatment.

Phosphorus is an ingredient in detergents, cleaning products and agricultural chemicals, and also gets into the wastewater streams via human waste. It is a particular problem because it is a nutrient for plant growth, and if it gets into the environment it encourages the overgrowth of aquatic plants in rivers, streams and ponds. This depletes dissolved oxygen in the water in a process called eutrophication. This then leads to loss of fish and insect life, damaging the health of watercourses.

Currently, phosphorus is removed at sewage treatment works by dosing wastewater with iron salts. However, tightening regulations on water quality are creating a need for new methods.