Purifying saline wastewater with algae

Purifying saline wastewater with algae

Algae are in high demand as food. A German-Chinese research team now wants to develop macroalgae for new applications.

Algen spielen zunehmend eine Rolle als Lebensmittel, aber die Reinigung des Abwassers aus den Zuchttanks ist wegen des Salzgehalts schwierig.
Algae are playing an increasingly important role as food, but the purification of wastewater from the breeding tanks is difficult due to the high salt content.

The demand for macroalgae is growing worldwide: aquatic plants are cultivated as food and animal feed, but are also used for the production of cosmetics, dietary supplements or as additives in animal feed because of their bioactive ingredients. Algae breeding is particularly widespread in China, where the alga Laminaria is of particular importance.

Problematic salt content in waste water

However, industrial breeding produces waste water with a salt content of around 20%. For many of the conventional microorganisms used in wastewater treatment, this concentration is inhospitable. A research group at Jabobs University Bremen, together with Chinese partners, would now like to use special microalgae to purify this wastewater.

Purification with adapted organisms

"From the extremely salty process water at the facilities on land, we want to isolate and identify local microalgae that can grow in these hypersaline wastewater," explains Song Wang of Jacobs University. The aim is not only to purify the wastewater by cultivating microalgae, but also to produce high-quality microalgae products for subsequent commercialization. This is possible because the microalgae use the degraded organic residues as raw materials for their metabolism and use enzymes to produce economically interesting compounds.

The project, which started in March, will continue until February 2020 and is funded by the Chinese provincial government of Shandong with 260,000 euros.

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