Algae for Bioremediation and Biofuel Production – A Synergistic Approach
Algae have captured global attention for its biofuel prospects, carbon sequestration capabilities and bioremediation potentials. While it has diverse roles to play in the world of clean technology, a synergistic approach to couple more than one application is less practised. While, CO2 capture and biofuel production has been demonstrated in commercial scale with reasonable success, the coupling of bioremediation with biofuel production has not made news in the world of clean technology. However, researchers at the Rochester Institute of Technology have successfully demonstrated that algae could efficiently perform double duty of waste water cleanup and biofuel production.
The researchers successfully demonstrated that three types of microalgae – Scenedesmus, Chlorella and Chlamydomonas could efficiently convert nutrients to fuel on a diet of municipal waste water, under harsh and salty environment. It was shown that the algae were able to gobble up 99 per cent of the ammonia, 88 per cent of the nitrate and 99 per cent of the phosphates. The researchers have come up with an excellent model for achieving this synergistic approach. In a two phase process, the algae would produce lipids in normal rate following usual metabolism during the first phase. Then, once the waste water is depleted of nitrogen and phosphates, the algae would be made to respond to starvation by turning their reserve nutrient stores into even more lipids. The lipids would be harvested by mechanical process, while the left over biomass is subjected to composting, fed into an anaerobic digester to make biogas.
The team of researchers initially have proposed to set up a 4000 litre plant while in subsequent years would develop economically feasible methods to treat 200000 litres of waste every day.
