Phosphate is removed by precipitation with calcium, aluminium or iron, resulting in the formation of non-soluble crystals.
Yet, despite treatment facilities, too many of these plant nutrients end up in the water column, leading to eutrophication, and the degradation of freshwater as well as marine environments.
At the same time, plant nutrients such as nitrogen and phosphorus are highly valued as fertilisers, enabling us to feed the world. Nitrogen-based fertilisers are produced from nitrogen gas at the expense of considerable amounts of climate change-causing fossil fuel. Phosphorus-based fertilizers are produced from a dwindling stock of mined ores.
The world we live in is both a world of waste, and a world of increasingly scarce resources. The concept of the circular economy relates to an economy that is regenerative by design, i.e. new economic activities are decoupled from the exploitation of finite resources such as mined ores and fossil fuels. The Brainwaves project centres on the capturing of valuable plant nutrients in liquid waste (the new resource) and on recycling these nutrients back for plant growth, thus avoiding eutrophication problems, and saving finite resources. Brainwaves exploits the abilities of the duckweed Lemna minor to grow rapidly on a wide variety of waste streams, to take up nitrogen and phosphorus from the water, and to produce a protein-rich biomass that can be used as an animal feed or a nitrogen- and phosphorus-rich soil improver. Thus, Brainwaves is developing the use of liquid waste as a new resource for a green farming sector.
Interested in this exciting work? Please visit our website, follow us on Twitter, or contact Project Manager Anna Power at anna.power@ucc.ie
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