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Tampere University of Technology
Optimization of microalgae cultivation in liquid digestate from pulp and paper mill
CitationTao, R., Lakaniemi, A-M., & Rintala, J. (2017). Optimization of microalgae cultivation in liquid digestate from pulpand paper mill. Paper presented at 1st International ABWET conference: Waste-to-Bioenergy: Applications toUrban Areas, Paris, France.Year2017
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Download date:07.08.2020
Optimization of microalgae cultivation in liquid digestate from
pulp and paper millR. Tao, A.-M. Lakaniemi, J.A. Rintala
Department of Chemistry and Bioengineering, Tampere University of Technology, P.O. Box 541, 33101 Tampere, Finland
IntroductionMicroalgae can efficiently remove nutrients from liquid digestates while
producing biomass that can be converted into bioenergy and biofuels (Xia
and Murphy, 2016). However, high ammonia levels in liquid digestates may
inhibit the microalgal growth, and therefore wastewater dilution plays an
important role in the optimization of the biomass production and nutrient
removal efficiency. Recently, a microalgae-utilizing biorefinery concept
integrated into a traditional pulp and paper mill has been suggested. In this
concept, liquid digestate of pulp and paper wastewater treatment biosludge
is used for microalgal cultivation (Kouhia et al., 2015; Kinnunen and Rintala,
2016).
ConclusionsS. acuminatus enabled higher biomass production and nutrient removal
efficiency than C. vulgaris when cultivated in the liquid digestate from pulp
and paper mill wastewater treatment. Compared to previous studies
reporting microalgal cultivation in real wastewaters, S. acuminatus growing
in the liquid digestate from the pulp and paper mill resulted in one of the
highest microalgal biomass concentrations. This finding promotes the
development of the microalgae-utilizing biorefinery concept integrated into
pulp and paper mills.
ReferencesKinnunen, V.; Rintala, J.A. (2016). Bioresource Technology, 221, 78–84.
Kouhia, M.; Holmberg, H.; Ahtila, P. (2015). Algal Research, 10, 41–47.
Xia, A.; Murphy, J.D. (2016). Trends in Biotechnology, 34, 264-275.
Singh, M.; Reynolds, D.L.; Das, K.C. (2011). Bioresource Technology, 102, 10841-10848.
Tuantet, K.; Temmink, H.; Zeeman, G.; Janssen, M.; Wijffels, R.H.; Buisman, C.J. (2014). Water Research, 55, 162-174.
Tan, X.B.; Yang, L.B.; Zhang, Y.L.; Zhao, F.C.; Chu, H.Q.; Guo, J. (2015). Bioresource Technology, 198, 340-350.
Marjakangas, J.M.; Chen, C.Y.; Lakaniemi, A.M.; Puhakka, J.A.; Whang, L.M.; Chang, J.S. (2015). Biochemical Engineering
Journal, 103, 177-184.
Ho, S.H.; Huang, S.W.; Chen, C.Y.; Hasunuma, T.; Kondo, A.; Chang, J.S. (2013). Bioresource Technology, 135, 157-165.
Materials and MethodsC. vulgaris and S. acuminatus were cultivated in ADPP from anaerobic
reactors operated at mesophilic conditions treating activated sludge from
pulp and paper industry wastewater treatment plant. The initial ammonium
and phosphate-P concentration of the liquid digestate were 350±40 mg/L
and 25±1 mg/L, respectively. The liquid digestate was diluted with deionized
water, using dilution factors of 5x, 3x and 1.5x. Cultivations with each
dilution were performed under 150 µmol photos/(m2·s) and 240 µmol
photos/(m2·s) for C. vulgaris and S. acuminatus, respectively, with 5% CO2
in the air (v/v) for 12 days.
Fig. 1 Photographs of the photobioreactors used in the experiments and the two
microalgae observed under microscope.
AcknowledgmentsThis project has received funding from the European Union’s Horizon
2020 research and innovation programme under the Marie Sklodowska-
Curie grant agreement No 643071.
ObjectivesThe aim of the present study was to study the cultivation of two freshwater
microalgae, Chlorella vulgaris and Scenedesmus acuminatus in a diluted
liquid fraction of the pulp and paper mill biosludge after anaerobic digestion
(ADPP). Simultaneous nutrient removal from the liquid digestate was also
investigated.
C. vulgaris S. acuminatus
Results
Fig. 2 Microalgal biomass concentration (as g VSS/L) during the cultivation of
Chlorella vulgaris and Scenedesmus acuminatus in differently diluted ADPP.
Medium Microalgae Maximum biomass concentration (g/L)
Reference
ADPP Chlorella vulgaris 5.1 This study
ADPP Scenedesmus acuminatus
9.4 This study
Anaerobically digested poultry litter
Scenedesmus bijuga 0.4 Singh et al., 2011
Human urine Chlorella sorokiniana
9.3 Tuantet et al., 2014
Anaerobically digested municipal wastewater
Chlorella pyrenoidosa
2.0 Tan et al., 2015
Anaerobically digested Piggery wastewater
Chlorella vulgaris 3.2 Marjakangas et al., 2015
Modified Basal Medium
Chlorella vulgarisFSP-E
7.2 Ho et al., 2013
Funded by
the European Union
Fig. 3 The soluble ammonium and phosphate removal efficiencies during the
cultivation of Chlorella vulgaris and Scenedesmus acuminatus in differently diluted
ADPP.
Table 1: Maximum biomass levels from selected studies in which microalgae were
cultivated in real wastewaters and synthetic medium.