Abstract : Natural flotation of D. salina is uncommon phenomenon, but in saline environments, this microalga acquires a unique flotation capacity due to its high carotenoid and lipid content, giving it a lower density compared to the highly saline brine density. Laboratory-scale evaluations of this flotation capacity yielded promising results, with a concentration factor of 10.71, recovery efficiency around 37% and 100% cell integrity, values comparable to those obtained via other preconcentration techniques such as flocculation. This preconcentration step was followed by a dewatering phase through centrifugation. Direct centrifugation alone was ineffective due to the high brine salinity and D. salina hydrophobicity, necessitating a salinity reduction step before optimal dewatering. Using single-factor and Box-Behnken design experiments, dewatering was optimized by studying centrifugation speed, salinity, and time, with centrifugation speed proving most influential. Optimal conditions (6500 rpm, 10 minutes, and 70 g/L salinity) resulted in 95.79% cell integrity and 98.79% recovery efficiency. These findings suggest that sequential preconcentration via flotation, followed by dilution and centrifugation, provides a sustainable method for saline environments, significantly enhancing both cost and energy efficiency.