Combined remediation and lipid production using Chlorella sorokiniana grown on wastewater and exhaust gases

Substitution of conventional feedstock with waste based alternatives is one route towards both remediation and reducing costs associated with production of algal biomass. This work explores whether exhaust gases and wastewater can replace conventional feedstock in the production of biomass from Chlorella sorokiniana. Exhaust gases were used to augment production in final effluent, anaerobic digester centrate or in standard medium. Cultures were grown in 1 L bottles under illumination of 80 μmol m−2 s−1. The results showed an average μmax ranging between 0.04 and 0.07 h−1, whilst the final biomass yield in different media ranged between 220 and 330 mg L−1. Lipid yield was increased over time to 31 mg L−1. CO2 addition resulted in complete nitrogen removal between 48 and 96 h in both final effluent and centrate. The results also indicated that levels of carbon monoxide, carbon dioxide and nitrogen oxides in the exhaust gases can be reduced by between 20% and 95%.