Water recycle and bacterial disinfection in Ettlia sp. cultivation

Abstract

As a possible solution for disadvantages of large scale microalgal cultivation, a low cost harvesting method and bacterial disinfection was studied. In order to adopt Ettlia sp. which is known as auto-flocculating species and having potential of lowering down harvesting cost for microalgal oil process, its medium reusability was checked. Compared to centrifugation and microfiltration, total carbohydrate and total protein remained same in each cycle. However, auto-flocculation cannot harvest bacteria in contaminated algal medium. In order to disinfect bacteria in supernatant, potential of hydrodynamic cavitation was checked. After pretreatment of recycled medium with HC, specific growth rate of cells in new medium and recycled medium with centrifuge, and the other recycled medium after auto-flocculation and cavitation was compared. The overall process of auto-flocculation with the harvesting and pretreatment of recycled medium was checked.