The recovery of selected heavy metals from water by the use of Microalgae, and analysis of biofuel produced from this algae

The overall aim for this project is to determine whether it is feasible to produce biofuels from algae that has been cultivated in wastewater contaminated with heavy metals. It has been previously reported that algae absorb metals internally by an irreversible mechanism, and although there is literature that covers the bio-recovery of metals using algae; these focus on recovering adsorbed metal.

This study will address the problems associated with recovering metal that has been internalised within the algae. To achieve this algae will first be cultivated in the presence of heavy metals to ensure that there is a ready source of contaminated biomass. During the cultivation stage, growth and absorption rates will be monitored; and the localisation of the metals within the cells will be determined over time.

Algae will then be processed to make the biomass suitable for component extraction. Both lipids and the metals will require purification for further processing downstream. Previous methods have proven to be inefficient in both energy requirements and product yield. A novel technique that is used in biopharmaceutical research has been identified as a possible alternative technique for lipid and protein recovery. This will be compared with established techniques for yield and potential.

The lipids will then be converted to biofuels by transesterification and will be analysed for metal content. Further tests will be performed to ensure that the fuel meets the requirements set out by the BS EN590 standards.