Digestate as Sustainable Nutrient Source for Microalgae—Challenges and Prospects

Applied Sciences

Karolína Ranglová¹  Jiří Masojídek¹  Lisa Bauer²  Bernhard Drosg²  Katharina Meixner² 

[1] Laboratory of Algal Biotechnology, Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, Novohradská 237, 379 81 Třeboň, Czech Republic;Tulln Research Site, BEST—Bioenergy and Sustainable Technologies GmbH, Konrad Lorenz Straße 20, 3430 Tulln, Austria;

关键词: sustainable nutrients;    digestate treatment;    nutrient requirements;    microalgae cultivation;    downstream processing;    biorefinery;   

DOI  :  10.3390/app11031056

来源: DOAJ

【 摘 要 】

The interest in microalgae products has been increasing, and therefore the cultivation industry is growing steadily. To reduce the environmental impact and production costs arising from nutrients, research needs to find alternatives to the currently used artificial nutrients. Microalgae cultivation in anaerobic effluents (more specifically, digestate) represents a promising strategy for increasing sustainability and obtaining valuable products. However, digestate must be processed prior to its use as nutrient source. Depending on its composition, different methods are suitable for removing solids (e.g., centrifugation) and adjusting nutrient concentrations and ratios (e.g., dilution, ammonia stripping). Moreover, the resulting cultivation medium must be light-permeable. Various studies show that growth rates comparable to those in artificial media can be achieved when proper digestate treatment is used. The necessary steps for obtaining a suitable cultivation medium also depend on the microalgae species to be cultivated. Concerning the application of the biomass, legal aspects and impurities originating from digestate must be considered. Furthermore, microalgae species and their application fields are essential criteria when selecting downstream processing methods (harvest, disintegration, dehydration, product purification). Microalgae grown on digestate can be used to produce various products (e.g., bioenergy, animal feed, bioplastics, and biofertilizers). This review gives insight into the origin and composition of digestate, processing options to meet requirements for microalgae cultivation and challenges regarding downstream processing and products.

【 授权许可】

Unknown