Algal wastewater treatment and biofuel production

Replacement of fossil fuels by renewable energy is being hotly debated globally. Biofuel has received much attention in recent years. Although numerous reports are available on the production of biofuel from oil-plants, such as soybean, sunflower and palm oils, the production of biofuel from microalgae is a newly emerging field. It is known that various types of inorganic and organic compounds such as carbon dioxide, nitrogen and mineral phosphorus in wastewater can be utilized by microalgae for lipids production. In order to remove nitrogen and phosphate from wastewater the Chlorella vulgaris species was used. Samples of digester supernatant in dilution of 15%, 25% and 50% were collected from wastewater treatment plant located in south of Tehran. After the cultivation of C. vulgaris in the prepared samples the results indicated that nitrogen and phosphate were removed at the highest level by 90%. In this condition the highest amount of biomass was obtained (2.7 g/l) in dilution of 25% and also the maximum lipid content of C. vulgaris was 27% in dilution of 15%. As a result, C. vulgaris cultivation in wastewater treatment systems can be used as a new strategy for removing of nitrogen and phosphate at high level without use of aeration, nitrification and denitrification systems.