Electrocoagulation reduces harvesting costs for microalgae.

0537288 - ÚCHP 2022 RIV GB eng J - Journal Article
Lucáková, Simona - Brányiková, Irena - Kováčiková, Sára - Pivokonský, Martin - Filipenská, Monika - Brányik, T. - Růžička, Marek
Electrocoagulation reduces harvesting costs for microalgae.
Bioresource Technology. Roč. 323, March (2021), č. článku 124606. ISSN 0960-8524. E-ISSN 1873-2976
R&D Projects: GA TA ČR(CZ) TJ01000297
Institutional support: RVO:67985858 ; RVO:67985874
Keywords : electrocoagulation * microalgae * chlorella
OECD category: Industrial biotechnology; Environmental sciences (social aspects to be 5.7) (UH-J)
Impact factor: 11.889, year: 2021
Method of publishing: Open access with time embargo

Centrifugation is the most commonly used method for harvesting autotrophically produced microalgae, but it is expensive due to high energy demands. With the aim of reducing these costs, we tested electrocoagulation with iron electrodes for harvesting Chlorella vulgaris. During extensive lab-scale experiments, the following factors were studied to achieve a high harvesting efficiency and a low iron content in the harvested biomass: electric charge, initial biomass concentration, pH, temperature, agitation intensity, residual salt content and electrolysis time. A harvesting efficiency greater than 95% was achieved over a broad range of conditions and the residual iron content in the biomass complied with legislative requirements for food. Using electrocoagulation as the preconcentration step prior to centrifugation, total energy costs were reduced to 0.136 kWh/kg of dry biomass, which is less than 14% of that for centrifugation alone. Our data show that electrocoagulation is a suitable and cost-effective method for harvesting microalgae.
Permanent Link: http://hdl.handle.net/11104/0315017