Despite the low removal efficiencies reported by previous studies, electro-flotation still stands out among other microalgae removal methods for its economical and environmental benefits. To enhance removal efficiency, the important factors that limit the performance of this method must be investigated. In this study, the possible ways of increasing the removal efficiency of microalgae have been explored by investigating the effects of several important variables in electro-flotation. Eight parameters, namely flotation time, rising time, current density, pH, conductivity, electrode distance, temperature and initial concentration were evaluated using a one-parameter-at-a-time approach. Results revealed that the operational parameters that greatly affected the removal efficiency of microalgae were electro-flotation time, current density, pH, and initial concentration. The effect of conductivity, electrode distance, and temperature on removal efficiency were insignificant. However, they exhibited positive an indirect positive effect on power demand, which is nowadays considered an equally important aspect in the running of a feasible and economically efficient electro-flotation process.

Abstract
 1. Introduction
 2. Materials and Methods
  2.1. Cultivation of microalgae
  2.2. Electro-flotation set-up
  2.3. Experimental procedure
  2.4. Analyses
 3. Results and discussion
  3.1. Effect of electro-flotation time and rising time
  3.2. Effect of Current density and pH
  3.3. Effect of conductivity and electrode distance
  3.4. Effect of temperature and initial concentration
 4. Conclusion
 REFERENCES

• Arpon Lucero Jr(Department of Environmental Science, Catholic University of Daegu)
• Dong-Seog Kim(Department of Environmental Science, Catholic University of Daegu)
• Young-Seek Park(DU University College, Daegu University) Corresponding author