Growth of Chlorella vulgaris on Sugarcane Vinasse: The Effect of Anaerobic Digestion Pretreatment

Abstract

Microalgae farming has been identified as the most eco-sustainable solution for producing biodiesel. However, the operation of full-scale plants is still limited by costs and the utilization of industrial and/or domestic wastes can significantly improve economic profits. Several waste effluents are valuable sources of nutrients for the cultivation of microalgae. Ethanol production from sugarcane, for instance, generates significant amounts of organically rich effluent, the vinasse. After anaerobic digestion treatment, nutrient remaining in such an effluent can be used to grow microalgae. This research aimed to testing the potential of the anaerobic treated vinasse as an alternative source of nutrients for culturing microalgae with the goal of supplying the biodiesel industrial chain with algal biomass and oil. The anaerobic process treating vinasse reached a steady state at about 17 batch cycles of 24 h producing about 0.116 m(3)CH4 kgCODvinasse (-1). The highest productivity of Chlorella vulgaris biomass (70 mg l(-1) day(-1)) was observed when using medium prepared with the anaerobic digester effluent. Lipid productivity varied from 0.5 to 17 mg l(-1) day(-1). Thus, the results show that it is possible to integrate the culturing of microalgae with the sugarcane industry by means of anaerobic digestion of the vinasse. There is also the advantageous possibility of using by-products of the anaerobic digestion such as methane and CO2 for sustaining the system with energy and carbon source, respectively.

Growth of microalgae Scenedesmus sp in ethanol vinasse

“…Barrocal et al (2010) showed that, in batch culture, Spirulina maxima was able to grow on Schlösser medium containing up to 5.0 g/L of diluted beet vinasse, reaching biomass concentrations between 3.5 to 4.8 g/L. The vinasse concentration applied in this study was similar to that used in Marques's (2013), where vinasse concentration was 2.0 g/L and biomass concentration was 0.7 g/L in a 10 days batch. In this study, the biomass concentration was equivalent when the equivalent percentage of vinasse was used.…”

“…Treatment of beet vinasse using a vinasse concentration of 5 g/L (supplemented with Schlösser medium) pre-treated anaerobically using the microalgae Spirulina maxima resulted in a production of 4.8 g/L of biomass in eleven days (Barrocal et al 2010). Marques (2013) worked on diluted vinasse treatment (2 gCOD/L) using C. vulgaris and obtained 0.49 g/L in seven days. There is currently no information on specific studies related to the use of Scenedesmus sp to treat this effluent.…”

Vinasse from Sugarcane Ethanol Production: Better Treatment or Better Utilization?

“…The use of digestate vinasse was used to cultivate the microalgae Chlorella vulgaris (Marques et al, 2013;Candido and Lombardi, 2017) and Neochloris oleoabundans (Olguín et al, 2015). Initially, research shows that vinasse was highly toxic to C. vulgaris at concentrations greater than 4%, reaching allowable concentrations of about 8.6% after treatment (Marques et al, 2013). C. vulgaris, a widely used species in accumulation of valuable microbial lipids (Reis et al, 2014b), was able to achieve specific growth rates of 0.76 day ) (Marques et al, 2013).…”

“…Initially, research shows that vinasse was highly toxic to C. vulgaris at concentrations greater than 4%, reaching allowable concentrations of about 8.6% after treatment (Marques et al, 2013). C. vulgaris, a widely used species in accumulation of valuable microbial lipids (Reis et al, 2014b), was able to achieve specific growth rates of 0.76 day ) (Marques et al, 2013). The use of AD can represent a feasible opportunity for making vinasse an appropriate cultivation medium for microbial cultivation, such as in the use of fungi with resilience to unfavorable conditions of growth (Reis et al, 2014a).…”

Estimating the elemental biomass composition of Desmodesmus sp. cultivated in sugarcane stillage

“…Currently, the algae used in the cultivation of the stillage medium are: Chlorella vulgaris [5][6][7], Chlorella sp. Bejerinck [8], Chlorella sorokiniana [9], Chlamydomonas reinhardii [10], Tetraselmis suecica [8], Scenedemsus sp.…”