Nutrient recovery for cleaner water and richer soils

Novel pellets adsorb phosphate from water in a simple and clean process

Spotted: Nutrients are chemical elements – such as nitrogen and phosphorus – that are needed by living organisms to grow. They are essential for agriculture and are added to farmland through fertilisers to maximise yields. But despite their importance for food security, nutrients can also be a problem if they are present in excess.

Nutrient pollution occurs when nutrients from sources such as sewage, manure, and fertiliser are swept into water systems. Once there, they can cause environmentally damaging algal blooms through a process called eutrophication. In the US, it is estimated that 15,000 bodies of water are impaired by nutrients in this way, while 78 per cent of US coastal water exhibits an overgrowth of algae.

US startup Water Warriors is tackling this problem, focusing – for now – on one particular nutrient: phosphorus. In collaboration with the US Environmental Protection Agency (EPA), the company has created ‘Poseidon Pellets’. Made from naturally occurring and sustainable mineral materials that are harmless to plants and wildlife, these pellets efficiently adsorb water-borne phosphate – a common phosphorus-containing chemical. Once adsorption has taken place, the pellets can then be used as a slow-release soil amendment for farming, recycling phosphorus to the land, where it is useful, rather than allowing it to stay in water systems as pollution.

Water Warriors’ technology can be used in a variety of settings, treating water wherever it is flowing, whether that be man-made channels and drains or natural lakes and streams. It can also be used to directly treat municipal, industrial, or agricultural wastewater effluents. Depending on the application, the Poseidon Pellets can be packaged into a variety of vessels and permeable containers including filter baskets and boom netting.

Poseidon is Water Warriors’ first product and current focus, but the startup is also working to develop ‘Neptune’, another pellet product for adsorbing nitrogen and ammonia – two other nutrients that contribute to water pollution.

Springwise has spotted several other innovations recovering nutrients from water and returning it to the land. For example, several companies are turning seaweed, which absorbs nutrients as it grows, into fertiliser and feed additives.

Written By: Matthew Hempstead