Tag Archives: microalgae

420-429 V. Skorupskaitė, V. Makarevičienė,, G. Šiaudinis and V. Zajančauskaitė
Green energy from different feedstock processed under anaerobic conditions
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Green energy from different feedstock processed under anaerobic conditions

V. Skorupskaitė¹, V. Makarevičienė¹,*, G. Šiaudinis² and V. Zajančauskaitė³

¹Aleksandras Stulginskis University, Faculty of Forest Sciences and Ecology, Institute of Environment and Ecology, Studentų Str. 11, LT53361 Akademija, Kauno district, Lithuania; *Correspondence: virginija.skorupskaite@asu.lt
²Vėžaičiai Branch of Lithuanian Research Centre for Agriculture and Forestry, Gargždų str. 29, LT96216 Vezaiciai, Klaipėda district, Lithuania
³Klaipėda University, Faculty of Marine Technology, Department of technological process. Herkaus Manto Str. 84, LT92294 Klaipėda, Lithuania

Abstract:

The possible use of energy crops and aquaculture for bioenergy production has only recently become a research target, so there is little information on their properties and advantages. The aim of this study was to investigate the possible use of cup plant, as well as marine and freshwater algae (Scenedesmus sp. and Chlorella sp.) for biogas production. Research of a batch anaerobic digestion process at a mesophilic temperature were performed using wet wastewater sludge, cattle manure, fresh microalgae biomass and dry marine algae, cup plant biomass and mixtures of these materials. The highest biogas yield (541.28 ml g-1 VS) was obtained by using a new feedstock from the microalgae Scenedesmus sp. biomass. That yield was 1.4 times higher than the biogas yield from cattle manure and 15% lower than the biogas yield from wastewater sludge. It was found that adding microalgae biomass to a cattle manure substrate increases biogas production approx. 1.5 times. The highest methane concentration in biogas produced from microalgae ranges from 64.87% to 66.66% and exceeds the methane amount (64.26%) in biogas produced from wastewater sludge. The methane amount in biogas produced from cattle manure, cup plant and marine algae biomass is lower than 60%. In addition, it was found that it is possible to produce 5,092.3 m3 of biogas or 113 GJ of energy from 1 ha of harvested cup plant biomass.

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445-454 K. Balina,, M. Balode, L. Muzikante and D. Blumberga
Impact of synthetic hormone 17α-ethinylestradiol on growth of microalgae Desmodesmus communis
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Impact of synthetic hormone 17α-ethinylestradiol on growth of microalgae Desmodesmus communis

K. Balina¹,*, M. Balode²⋅³, L. Muzikante² and D. Blumberga¹

¹Riga Technical University, Institute of Energy Systems and Environment, Azenes Str. 12/1, LV1048 Riga, Latvia; *Correspondence: karina.balina@rtu.lv
²Latvian Institute of Aquatic Ecology, Daugavgrivas 8, LV1048 Riga, Latvia
³University of Latvia, Faculty of Biology, Department of Hydrobiology, Kronvalda Boulevard 4, LV1010 Riga, Latvia

Abstract:

Microalgae has recently attracted much attention as a feedstock for biogas. Using wastewater as microalgae nutrition is a way how to produce algal biomass with low cost and minimum impact on environment. However, wastewater often is polluted with chemicals like pharmaceuticals which are among the commonly used chemicals in everyday life. The present study was aimed at the toxicity evaluation of a commonly used synthetic hormone, 17α-ethinylestradiol, using freshwater green algae Desmodesmus communis as a biotest organism. Parameters like healthy cell number and photosynthetic activity were determined and used to assess the toxicity. Lowest Observed Effect Concentration (LOEC) and 50% Effective Concentration (EC50) values were calculated for the parameters at different incubation times. It was found out that 17α-ethinylestradiol affects algal cell ability to grow, inhibits cell division and reduce photosynthetic processes in algal cells. Our research shows that inhibitory effect on growth of green algae D. communis start on concentration below 10 µg L-1 (4–8 µg L-1). Concentrations in the range of concentration 80–100 reduce growth by 50%, but concentrations 100–500 µg L-1 induce 100% reduction of growth rate and even calls initial algal cell destruction. Presence of EE2 in wastewater used for algal growth can affect productivity of a microalgae aquaculture.

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373-390 L. Podkuiko, K. Ritslaid, J. Olt and T. Kikas
Review of promising strategies for zero-waste production of the third generation biofuels
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Review of promising strategies for zero-waste production of the third generation biofuels

L. Podkuiko*, K. Ritslaid, J. Olt and T. Kikas

¹Institute of Technology, Estonian University of Life Sciences, Kreutzwaldi 56, 51014 Tartu, Estonia; *Correspondence: lara.podkuiko@emu.ee

Abstract:

Biodiesel obtained from microalgae is considered a promising alternative to conventional diesel fuel. However, it has been proposed that cultivation of algae for the sole purpose of making biodiesel is neither economically efficient nor sustainable. Nevertheless, there are several ways in which microalgae can be utilized to their full potential. One possibility is to view the cultivation and utilization of microalgae as a complex process that includes wastewater treatment, carbon dioxide sequestration, production of nutritional supplements, biofuels etc. The aim of this paper is to review the most promising possibilities of combining different cultivation strategies/technologies with the coproduction of high value products (e.g. Ω-fatty acids) and biofuels (algal diesel, ethanol and biogas).

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33-38 G. Mann, M. Schlegel, R. Schumann and A. Sakalauskas
Biogas-conditioning with microalgae
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Biogas-conditioning with microalgae

G. Mann¹, M. Schlegel¹, R. Schumann² and A. Sakalauskas³

¹ Institute for Farm Animals Sciences and Technology, Faculty for Agricultural and
Environmental Sciences, University of Rostock, Rostock, Justus-von-Liebig Weg 8, D-18059
Rostock,
² Institute for Biosciences, Faculty for Mathematics and Natural Sciences, University of
Rostock, Albert-Einstein-Str. 3, D-18059 Rostock
³ Department of Agricultural Machinery, Faculty of Agricultural Engineering, Lithuanian
University of Agriculture, Student� 15A, LT-53361 Kaunas-Akademija, Lithuania,
e-mail: ZUM.katedra@lzuu.lt

Abstract:

To promote the expansion of feasible biogas production, an optimisation of the whole process chain is essential. In this context the optimisation of the biogas-conditioning process is of great importance. By improving this process, new fields of application, e.g. its usage as car fuel or natural gas substitute can be developed. Currently applied chemical/physical conditioning techniques are cost intensive and hinder a reasonable production for smaller biogas plants. At present a possible low-cost alternative by application of microalgae is being investigated at the University of Rostock. To determine their ability to reduce carbon dioxide from biogas, laboratory-scale photobioreactors with a culture volume of 0.45 l are deployed. In 2008 the microalgae Chlorella sp. was analysed in terms of conditioning biogas. As a result the biogas components CO2 and H2S could be reduced up to 97.07% and 100%, respectively. Also an increase of microalgae cell count could be documented, which provides interesting alternatives for the production of algae ingredients.

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