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Large-scale production of biofuels from algae may cause water pollution

Gepubliceerd op
7 oktober 2014

Biofuels can be produced from micro-algae grown in ponds or tubes on land. This requires considerable fertilizer inputs that may pollute the environment if not treated properly. To ensure sustainable production of biodiesel from micro-algae, it is important to develop cultivation systems with low nutrient losses to the environment.

Biofilm made of algae (growing in some hours) at low tide, the wet sand on the west side of the beach of Morgat (Crozon-Morgat, Finistère, France) (picture: Lamiot)
Biofilm made of algae (growing in some hours) at low tide, the wet sand on the west side of the beach of Morgat (Crozon-Morgat, Finistère, France) (picture: Lamiot)

In our article ‘Possible future effects of large-scale algae cultivation for biofuels on coastal eutrophication in Europe’ (2014) we analyse possible eutrophication of the coastal waters of the European Union for future scenarios assuming that biofuel production will increase. The results indicate that the amount of nitrogen and phosphorus in the coastal waters may increase considerably in the future as a result of large-scale production of algae for the production of biodiesel, even in scenarios assuming effective waste water treatment and recycling of waste water in algae production.

About 2% of the land in Europe would be needed to cultivate enough algae to meet the demand for biodiesel for the whole Union. An advantage of algae is that cultivation can be carried out anywhere in the European Union. We assumed that the cultivation is evenly spread over the Union. During the cultivation waste will partly be transported to the coastal waters.

H. Blaas
H. Blaas

Our scenarios show that without efforts to close nutrient cycles in algae parks and without efficient waste water treatment, the impact of large-scale algae production on the environment may be considerable. These conclusions hold for all our scenarios. One may, therefore, argue that micro-algae can only become a sustainable basis for biodiesel, in case the losses of N and P to the environment are minimized. Our advice is to use all the technical possibilities to produce a minimum of waste by the cultivation of algae.

Reference

Blaas, H., Kroeze, C. (2014) Possible future effects of large-scale algae cultivation for biofuels on coastal eutrophication in Europe. Science of The Total Environment 496, 45-53.