Attachment of Chlamydomonas acidophila utilising different materials to enhance the nutrient recovery from wastewaters

The objective of this study was to evaluate the nutrient recovery by Chlamydomonas acidophila using different attachment material in order to potentially improve nutrient removal and simplify the harvesting of the algal cells. Four different materials were studied: cotton, non-treated wool, polyethylene and recycled plastic carriers. Batch and repeated fed-batch laboratory scale experiments were carried out. Non-treated wool showed the best cell attachment and removal of ammonium and phosphate (9 and 7 mg L-1d-1 respectively). Therefore, it can be concluded that non-treated wool appears to be a suitable material for microalgae cell attachment. Furthermore, the immobilization of algae with no obvious reduction in nutrient removal offers the possibility that biological nutrient recovery may be feasible on a larger scale and this will be investigated in future pilot-scale studies utilizing domestic effluents as a nutrients source.