Digestate as Sustainable Nutrient Source for Microalgae-Challenges and Prospects

0541607 - MBÚ 2022 RIV CH eng J - Journal Article
Bauer, L. - Ranglová, Karolína - Masojídek, Jiří - Drosg, B. - Meixner, K.
Digestate as Sustainable Nutrient Source for Microalgae-Challenges and Prospects.
Applied Sciences-Basel. Roč. 11, č. 3 (2021), č. článku 1056. E-ISSN 2076-3417
EU Projects: European Commission(XE) 727874 - SABANA
Grant - others:European Regional Development Fund(CZ) ATCZ221
Program: Interreg ČR-At
Institutional support: RVO:61388971
Keywords : sustainable nutrients * digestate treatment * nutrient requirements * microalgae cultivation * downstream processing
OECD category: Microbiology
Impact factor: 2.838, year: 2021
Method of publishing: Open access
https://www.mdpi.com/2076-3417/11/3/1056

This review provides insight into the origin of digestate and how it can be processed to meet requirements for microalgae cultivation as well as challenges that occur in cultivation, in downstream processing, and in terms of products when using this nutrient source.
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.
Permanent Link: http://hdl.handle.net/11104/0319140