FERREIRA, W. B.; http://lattes.cnpq.br/5630172788119332; FERREIRA, Weruska Brasileiro.
Résumé:
Fossil fuels to be an inexhaustible source became a worldwide concern because of the need to
meet excessive demand both in industrial and transportation. A major concern with current
fossil fuels is the harmful/hazardous environmental effect it causes by the generation of gases
that cause global overheating warming. These reasons this concern have led man looking for
new sources of renewable energy. In this regard, oilseeds have become the main source of
biofuels, though it has been under heavy criticism mainly because of the excessive use of
arable land that would compromise the generation production of food. Another source of
renewable energy that does not present this difficulty is biofuel from microalgae. The
(microalgae) need adequate nutrients for development. These nutrients can be from the
preparation of a synthetic or supplied form other sources, such as the use of domestic
wastewater, brackish waters and other waste. This study examined the feasibility of (growing)
microalgae Chlorella sp and Chlorella vulgaris in a modified culture medium with addition of
the concentrate product from the process of desalination of brackish water via the reverse
osmosis in order to evaluate the potential production of the biodiesel microalgae studied. This
study was conducted in two stages: the first step carried out studies in a bench scale,
developed in the LABDES/UFCG and BIOTEC/UFSC laboratories. In this step, two strains
of Chlorella sp (TU1 and TU3) and a strain of Chlorella vulgaris were grown in culture
medium Bold's Basal Medium (BMB) and there growth assessed. The culture was carried out
at 26 C under illumination 5klux and a photoperiod of 12 hours with continuous stirring.
Chlorella vulgaris showed higher productivity growth, reaching a maximum cell growth of
5.9xl07eeLmL_1e with lipid content of 8.56%. In the fatty acid profile analyzed by gas
chromatography,34.68% of the fatty acids were saturated. The studies followed with culture
media modification by addition of the concentration. The track showed a better cell growth
yield and with lipid was added to the culture medium 10-25% of the concentrate. 25% of the
concentrate to in the culture medium corresponded to a conductivity of 1.622u.S.cm"' and
approximately 1054.30 mg.L"1 SDT. A cell density of 4.7 x 107cel.mL"' was obtained, which
had a lipid content of 9.76%, 40.57% saturated fatty acids, the levels of carbohydrates and
proteins remained unchanged with respect to culture in 100% of BBM. The separation of the
cell type by means of flocculation was inefficient due to the great loss of biomass. The
separation process by microfiltration membranes showed better efficiency. The second stage
of this work was developed in raceway ponds of4000L, Urucu located in the community,
district of the ray tracing-PB. The results obtained in these ponds were not satisfactory. The
lipids contents were 2.88%, there was also a decrease in protein and carbohydrates
concentrations, mainly due to variations in temperature and luminance. The culture in the
open proved highly complex to operate in local weather conditions which hampered cell
development. However, under conditions of a laboratory scale photobioreactors, the use of the
concentrate was viable because it provided excellent cell growth while maintaining high
values of carbohydrates and proteins, except for fatty acids, thus showing the possibility of
minimizing the environmental impacts caused by concentrated.
