Anaerobic digestion of Spirulina sp. and Scenedesmus sp.: a comparison and investigation of the impact of mechanical pre-treatment

Inglesby, A E; Griffiths, M J; Harrison, S T L; Van Hille, R P

Anaerobic digestion of Spirulina sp. and Scenedesmus sp.: a comparison and investigation of the impact of mechanical pre-treatment

dc.contributor.author	Inglesby, A E
dc.contributor.author	Griffiths, M J
dc.contributor.author	Harrison, S T L
dc.contributor.author	Van Hille, R P
dc.date.accessioned	2018-03-01T09:20:03Z
dc.date.available	2016-05
dc.date.available	2018-03-01T09:20:03Z
dc.date.issued	2015-05
dc.description.abstract	AAnaerobic digestion (AD) is a unit process that integrates beneficially and sustainably into many bioprocesses. This study assesses and compares the production of methane from the biomass of the microalga Scenedesmus sp. and the cyanobacterium Spirulina sp. in batch anaerobic digesters. Anaerobic digestion of whole cell Spirulina resulted in a substantially higher methane productivity (0.18 L CH4 Lreactor −1 day−1) and methane yield (0.113 L CH4 g−1 volatile solids (VS)) compared to the digestion of whole cell Scenedesmus (0.12 L CH4 Lreactor −1 day−1 and 0.054 L CH4 g VS−1). Spirulina, possibly due to a combination of osmotic shock, the filamentous nature of the cells and lower mechanical strength of the non-cellulosic cell wall, was more readily degraded by hydrolytic and acidogenic microorganisms, resulting in the generation of a greater amount of acetic acid. This in turn provided greater substrate for methanogens and hence higher methane yields. In addition, Spirulina cells could be disrupted mechanically more quickly (1 h) than Scenedesmus cells (4 h) in a bead mill. Mechanical pre-treatment improved the final methane yields (L CH4 g VS−1) obtained from digestion of both substrates; however, the improvement was greater for Scenedesmus. Mechanical pre-treatment resulted in a 47 % increase in methane production for Spirulina compared to 76 % increase for Scenedesmus fed digesters. The more substantial increase observed for Scenedesmus was due to the relatively inefficient digestion of the whole, unruptured cells.	en_ZA
dc.identifier.apacitation	Inglesby, A. E., Griffiths, M. J., Harrison, S. T. L., & Van Hille, R. P. (2015). Anaerobic digestion of Spirulina sp. and Scenedesmus sp.: a comparison and investigation of the impact of mechanical pre-treatment. <i>Journal of Applied Phycology</i>, http://hdl.handle.net/11427/27611	en_ZA
dc.identifier.chicagocitation	Inglesby, A E, M J Griffiths, S T L Harrison, and R P Van Hille "Anaerobic digestion of Spirulina sp. and Scenedesmus sp.: a comparison and investigation of the impact of mechanical pre-treatment." <i>Journal of Applied Phycology</i> (2015) http://hdl.handle.net/11427/27611	en_ZA
dc.identifier.citation	Inglesby, A.E., Griffiths, M.J., Harrison, S.T.L. & van Hille, R.P. 2015, Anaerobic digestion of Spirulina sp. and Scenedesmus sp.: a comparison and investigation of the impact of mechanical pre-treatment, Journal of Applied Phycology, vol. 27, no. 5, pp. 1891-1900	en_ZA
dc.identifier.ris	TY - Journal Article AU - Inglesby, A E AU - Griffiths, M J AU - Harrison, S T L AU - Van Hille, R P AB - AAnaerobic digestion (AD) is a unit process that integrates beneficially and sustainably into many bioprocesses. This study assesses and compares the production of methane from the biomass of the microalga Scenedesmus sp. and the cyanobacterium Spirulina sp. in batch anaerobic digesters. Anaerobic digestion of whole cell Spirulina resulted in a substantially higher methane productivity (0.18 L CH4 Lreactor −1 day−1) and methane yield (0.113 L CH4 g−1 volatile solids (VS)) compared to the digestion of whole cell Scenedesmus (0.12 L CH4 Lreactor −1 day−1 and 0.054 L CH4 g VS−1). Spirulina, possibly due to a combination of osmotic shock, the filamentous nature of the cells and lower mechanical strength of the non-cellulosic cell wall, was more readily degraded by hydrolytic and acidogenic microorganisms, resulting in the generation of a greater amount of acetic acid. This in turn provided greater substrate for methanogens and hence higher methane yields. In addition, Spirulina cells could be disrupted mechanically more quickly (1 h) than Scenedesmus cells (4 h) in a bead mill. Mechanical pre-treatment improved the final methane yields (L CH4 g VS−1) obtained from digestion of both substrates; however, the improvement was greater for Scenedesmus. Mechanical pre-treatment resulted in a 47 % increase in methane production for Spirulina compared to 76 % increase for Scenedesmus fed digesters. The more substantial increase observed for Scenedesmus was due to the relatively inefficient digestion of the whole, unruptured cells. DA - 2015-05 DB - OpenUCT DP - University of Cape Town J1 - Journal of Applied Phycology LK - https://open.uct.ac.za PB - University of Cape Town PY - 2015 T1 - Anaerobic digestion of Spirulina sp. and Scenedesmus sp.: a comparison and investigation of the impact of mechanical pre-treatment TI - Anaerobic digestion of Spirulina sp. and Scenedesmus sp.: a comparison and investigation of the impact of mechanical pre-treatment UR - http://hdl.handle.net/11427/27611 ER -	en_ZA
dc.identifier.uri	http://hdl.handle.net/11427/27611
dc.identifier.vancouvercitation	Inglesby AE, Griffiths MJ, Harrison STL, Van Hille RP. Anaerobic digestion of Spirulina sp. and Scenedesmus sp.: a comparison and investigation of the impact of mechanical pre-treatment. Journal of Applied Phycology. 2015; http://hdl.handle.net/11427/27611.	en_ZA
dc.language.iso	eng
dc.publisher	Springer	en_ZA
dc.publisher.department	Centre for Bioprocess Engineering Research
dc.publisher.faculty	Faculty of Engineering and the Built Environment
dc.publisher.institution	University of Cape Town
dc.source	Journal of Applied Phycology	en_ZA
dc.source.uri	https://link.springer.com/journal/10811
dc.source.uri	https://link.springer.com/journal/10811
dc.subject.other	Anaerobic digestion
dc.subject.other	Biogas
dc.subject.other	Methane
dc.subject.other	Scenedesmus
dc.subject.other	Spirulina
dc.subject.other	Algae
dc.title	Anaerobic digestion of Spirulina sp. and Scenedesmus sp.: a comparison and investigation of the impact of mechanical pre-treatment	en_ZA
dc.type	Journal Article	en_ZA
uct.type.filetype	Text
uct.type.filetype	Image
uct.type.publication	Research	en_ZA
uct.type.resource	Article	en_ZA