Linnaeus University researchers are using algae to clean the sea

Green Solutions

Tomorrow is International Water Day, and the theme is ‘Nature for Water: How to use what we already have to reduce water pollution’.

A group of marine biologists at Linnaeus University in Kalmar, Sweden are doing just that. They are teaming up with local industries in a project called Algoland and using naturally occurring algae to clean waste water excess nutrients, a major and growing problem that causes overgrowth, or ‘eutrophication’, in the Baltic Sea.

The Baltic Sea is polluted, choking for oxygen due to the explosive growth of algal blooms, a problem created by agricultural run off causing excess nutrient inputs into the sea. But even in the most dismal of climate change scenarios there remains hope.

Dr Catherine Legrand, a professor of marine microbiology and the head of the Algoland project, knew first hand of the remarkable potential to use algae for sustainable solutions. ‘About 10 years ago, I asked myself, ‘How can we use algae to solve climate change problems? How can we use it to clean the air and water?’’ she said.

Microalgae are microscopic, single celled plants. When they grow, they undergo the process of photosynthesis, absorbing carbon dioxide, nutrients and water. Since the research group is working in a coastal area with a surfeit of algae, CO2 and nutrients, it is the perfect breeding ground for testing their theory: that microalgae can be used to clean the air and water.

The Algoland project started in 2014 as a partnership between Degerhamn Cementa and Linnaeus University to use the factory’s flue gas to grow microalgae, thus absorbing the excess carbon dioxide that would otherwise be sent into the atmosphere. It has since flourished into no fewer than 17 partnerships from both industry and government, and a team of Linnaeus University microbiologists. In the rapidly growing project, microalgae are used to address a variety of climate problems in the region. They are cleaning air, water and are even being tested as a potential for valuable bio products such as animal fodder and biofuel.

Algoland has also teamed up with KSRR, the waste management company in the Kalmar region of Sweden, and Kalmar Energi, the city’s local power station for cleaning the waste water from the city’s landfill. Filling large raceway ponds with nutrient rich wastewater and adding carbon dioxide gas from the Kalmar Energi plant, Algoland researchers grow Baltic Sea algae.

At Moskogen landfill, algae are using the excess nutrients in the wastewater to grow, essentially cleaning the water in the process. When the water reaches the Baltic Sea, it no longer contains the excess nutrients that contribute to the widespread eutrophication problem.

The Linnaeus researchers return to the lab with the algal biomass that they have harvested and study it for quality and composition. Their efforts are to determine the potential of the biomass to be used for high quality bio products, such as manure and animal fodder. But their greatest product from this experiment? Clean water, and a healthier, brighter future for the Baltic Sea.