INSTITUTO DE INVESTIGACIONES EN ENERGIA NO CONVENCIONAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Production of microalgae in sewage effluents for sanitation, reuse of water and byproducts
GONZÁLEZ LEIVA, NANCY; MANRIQUE, SILVINA M; FRANCO, JUDITH; DÍAZ, DÉBORA
Congreso; World Congress and Expo on Biotechnology and Bioengineering; 2016
Manipal University Dubai
Our objective is to evaluate the potential of microalgae to grow in sewage effluents, comparing three different methods (cell count, absorbance and chlorophyll). Since the production of algal biomass requires significant inputs of nutrients, radiation and CO2, it would be possible to offset water treatment costs by utilizing algae in tertiary processes of sewage treatment in the north of Argentina -one of the seven regions with higher levels of solar radiation in the world. Tests in culture medium (modified Detmer) show a positive response of Scenedesmus quadricauda to the addition of nutrients: i) growth of 10% (g/l) with calcium nitrate (at 12%/wt); (ii) 26% with potassium phosphate (12%/wt); iii) 60% with glucose (8 g/l). A scaling was performed from 1x to 10x. In all cases 4 concentrations of sewage effluent were used (25, 50, 75 and 100%), achieving a gradual acclimatization of the specie to the effluent. Growth cycles were 20 days. For 50% dilution, the algae growth was similar to that obtained with the standard medium (H = 0.38, p = 0.984), meaning 94% of the latter. For 25% effluent concentration, the algal growth was 130% higher than using only standard medium (H = 2.81, p = 0.589). For a higher concentration, algae begin to decline from the seventh day. It is currently working with scaling (100x), observing if the recommendation emanating from the present, using a maximum of 50% effluent in the dilution, continues to maintain the same trend. Because almost 20% of households in the country are located in places close to contaminated water, this project could have a major social impact by reducing risk on human health and allowing water use in new activities, especially associated with areas with resource scarcity. Moreover, algal biomass contain many useful substances and we are exploring different use possibilities.