3rd meeting of young researchers at UP 1 - IJUP - Universidade do ...

Chlorella vulgaris for Wastewater Treatment and Lipid Production
V. Ramos 1 , T. Mata 1,a , N. Caetano 2,a , O. Oliveira 2
a LEPAE – Laboratory for Process, Environmental and Energy Engineering
1 Faculty of Engineering, University of Porto (FEUP), R.. Dr. Roberto Frias S/N, 4200-465 Porto,
Portugal
2 School of Engineering (ISEP), Polytechnic Institute of Porto (IPP), R. Dr. António Bernardino de
Almeida, 4200-072 Porto, Portugal
This study aims to analyze the effectiveness of using microalgae Chlorella vulgaris for
wastewater treatment and lipid production. The choice of this microalgae specie was done after
a careful literature revision, due to its high biomass growth rate and its easy adaptation to be
grown in open ponds. The origin of the wastewater to be treated is the dairy industry. Few
studies have been done concerning microalgae growth in this type of effluent, which can be
treated using microalgae due to its high rate of biodegradability [1-3]. After treatment, the algal
biomass must be separated from the treated effluent and its lipids can be then extracted for
biodiesel production [4].
It should be noted that the dairy effluent studied was not collected from a dairy industry but
simulated in laboratory. The reason for this is that the characteristics of a dairy effluent vary
widely, making it difficult or even impossible to perform the analysis. For this reason, a
simulated dairy wastewater was prepared by mixing different amounts of milk and de-ionized
water in order to prepare one liter of final solution. The amounts of milk used are 4, 8, 12, and
20mL. Additionally, other one liter solutions were prepared using the same volumes of milk,
but also adding to the culture medium some nutrients normally used for microalgae growth.
This way it was possible to determine the more adequate mix of milk and water and if other
nutrients are required in the culture medium for an efficient wastewater treatment and
microalgae growth. Results of this study allows one to compare which is the best culture
medium for microalgae and to relate the amount of milk or nutrients added and the algal
biomass growth, which is measured by absorbance using a spectrophotometer UV visible.
Results also showed that the better volume of milk is around 12mL with or without the
addition of extra nutrients.
References:
[1] Woertz I., Feffer A., Lundquist T., Nelson Y. Algae Grown on Dairy and Municipal Wastewater for
Simultaneous Nutrient Removal and Lipid Production for Biofuel Feedstock. Journal of Environmental
Engineering 2009, 1 115-1122.
[2] Wang L., Li Y., Chen P., Min M., Chen Y., Zhu J., Ruan R. R. Anaerobic digested dairy manure as
a nutrient supplement for cultivation of oil-rich green microalgae Chlorella sp. Bioresource Technology
2009; 1-6.
[3] Janczukowicz W., Zielinski M., Debowski M. Biodegradability evaluation of dairy effluents
originated in selected sections of dairy production. Bioresource Tech. 2008; 99; 4199-4205.
[4] Mata, TM; Martins, AA; Caetano, NS. Microalgae for Biodiesel Production and Other Applications:
A Review. Renewable & Sustainable Energy Review, 2010, 14, 217-232.
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