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ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Bio-oils Research » Research » Publications at this Location » Publication #316576
Title: Evaluating the usability of 19 effluents for heterotrophic cultivation of microalgal consortia as biodiesel feedstock

Author
item JORDAAN, E - Tshwane University
item ROUX-VAN-DER-MERWE, M - Tshwane University
item BADENHORST, J - Tshwane University
item Knothe, Gerhard
item BOTHA, B - Tshwane University

Submitted to: Journal of Applied Phycology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/2/2017
Publication Date: 11/27/2017
Citation: Jordaan, E., Roux-Van-Der-Merwe, M.P., Badenhorst, J., Knothe, G.H., Botha, B.M. 2017. Evaluating the usability of 19 effluents for heterotrophic cultivation of microalgal consortia as biodiesel feedstock. Journal of Applied Phycology. 30(3):1533-1547. https://doi.org/10.1007/s10811-017-1341-x.
DOI: https://doi.org/10.1007/s10811-017-1341-x

Interpretive Summary: Biodiesel, which is commonly obtained from various plant oils, animal fats or used cooking oils, is an alternative to conventional petroleum-derived diesel fuel. In recent years, oils produced by algae have found considerable interest because of the possible yield of these oils. In this work, algae were grown on industrial effluents. The background of this work is to investigate the potential utility of such waste material for lowering algae production costs and also to remediate contaminants in these effluents as algae can use some of the components as nutrients. The work showed that algae growth depends on the effluent type and not the type of algae. Best results were obtained with an effluent giving good growth followed by an effluent improving oil yield in the algae. The oils were similar in composition so that the growth medium has a decisive influence on this aspect. Biodiesel was prepared from the oils themselves and the properties studied. With the exception of cold flow, most properties of the biodiesel fuels were acceptable.

Technical Abstract: A key reason inhibiting commercialization of algal oil as biodiesel feedstock, is cultivation cost. For this reason, the usability of 19 readily available industrial effluents (autoclaved and non-autoclaved) to support heterotrophic growth and lipid accumulation was evaluated using six mixed algal cultures. Autoclaved whey effluent was the best with 14.32 g biomass/L, 13.23% lipids, resulting in a lipid production of 1.91 g lipids/L. Biomass production and lipid accumulation were in many cases inverse, e.g. mixed algal culture termed TUT4 accumulating 84.25% lipids on autoclaved acid mine drainage, with very little biomass produced. Biomass production was dependent on the effluent type, whereas the lipid accumulation was influenced mostly by the specific mixed algal cultures. The fatty acid composition of the algal oil (fish cannery and whey 30 effluents) showed high saturation, leading to acceptable cetane numbers, kinematic viscosity, good oxidative stability, but poor cold flow properties.