Potential use of vegetable waste for biofuel production

BACKGROUND In this study, the use of vegetable waste as a potential source of raw material for biofuel production was investigated. The microalga Chlorella vulgaris was used to maximize the production of lipids and carbohydrates. The culture medium was prepared with vegetable waste and diluted in the following proportions of medium:water: 1:0, 1:1, 1:2 and 1:3; the resulting solutions were adjusted for three different pH values (5.5, 7.2, 8.5). For a comparative analysis, modified CHU‐10 medium was used. RESULTS The initial concentration of carbon in the medium was 279.6 ± 3.5 mg L−1, while nitrogen was 11.22 ± 1.32 mg L−1. The growth in heterotrophic conditions was performed for 21 days, during which it was observed that higher concentrations of biomass and higher productivity of lipids and carbohydrates were obtained in cultures performed in medium without dilution (1:0) and pH 5.5; however, higher yields of lipids and carbohydrates were obtained when the medium was diluted in the proportion 1:3 and with alkaline pH. CONCLUSION The results of this study should encourage the use of vegetable waste as raw material for the production of microalgae rich in lipids and carbohydrates for the production of environmentally friendly fuels. © 2016 Society of Chemical Industry