Sustainable dewatering of microalgae by centrifugation using Image 4-focus and MATLAB edge detection

In this study, we demonstrate the feasibility of centrifugation for the successful dewatering of microalgae species. Centrifuge experiments were conducted on Scenedesmus quadricauda and Chlorella vulgaris at different centrifugal speeds between 1000-4000 (rpm) and varying time between 5-30 (min). Dewatering efficiency and microalgae cell disruption were evaluated.
Image-focus 4 and Matlab edge detection software were used to model the effect of centrifugation on microalgae cell walls and to determine the water removal ratio. Experimental results indicated that centrifugation technique is an effective approach for dewatering microalgae under specific conditions. Scenedesmus quadricauda showed a maximum dewatering efficiency of 82% and Chlorella vulgaris of 91%. Centrifugation under 4000 rpm at 10 minutes did not show any significant cell damage on the algae cell structure for both species. This study provides information on specific impact of centrifugation on Scenedesmus quadricauda and Chlorella vulgaris for the first time, which is, centrifugation technique under specific conditions (4000 rpm for 10 min) is a successful method for dewatering microalgae without damage to the cell wall. This study therefore provides sustainable option for microalgae dewatering technique in the energy industry.