H. Agnes Kurniawati, Suryadi Ismadji, J.C. Liu
This study aims to investigate the harvesting of microalgae by dispersed air flotation (DiAF) using natural biosurfactant saponin as the collector and chitosan as the flocculant. Two types of microalgae, Chlorella vulgaris and Scenedesmus obliquus, were used in this study. It was observed that saponin was a good frother, but not an effective collector when used alone for flotation separation of algae. However, with the pre-flocculation of 5. mg/L of chitosan, separation efficiency of >93% microalgae cells was found at 20. mg/L of saponin. Removal efficiency of >54.4% and >73.0% was found for polysaccharide and protein, respectively at 20. mg/L of saponin and chitosan each. Experimental results show that DiAF using saponin and chitosan is effective for separation of microalgae, and algogenic organic matter (AOM). It can potentially be applied in the integrated microalgae-based biorefinery. © 2014 Elsevier Ltd.
Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, 43 Keelung Road, Section 4, Taiwan; Department of Chemical Engineering, Widya Mandala Catholic University, Surabaya 60114, Kalijudan 37, Indonesia