Chlamydomonas acidophila as an alternative for phosphorus recovery from wastewater

Phosphorus (P) is an essential, indispensable, but non-renewable, nutrient used as a fertiliser; however, excessive use and potential discharge of P into the environment can lead to eutrophication. Therefore, recovering P from waste streams has become a major EU objective and the main goal of the Interreg NWE Phos4You project. Chlamydomonas acidophila appears to have potential for P recovery from small wastewater treatment plants (WWTP) as it requires low light intensities for growth, one of the limiting factors in microalgae technology. This study investigates the effect of light/dark (L/D) cycles at a very low light intensity on C. acidophila’s growth and nutrient consumption from wastewater. At a constant light intensity of 43µmol photons m-2 s-1, C. acidophila eliminated about 1.5mg PO4 L-1d-1 and achieving a growth rate of about 0.9 d-1. However maximum P removal efficiency per lit hour was obtained using 12/12 L/D over the incubation period.