Harvesting of oleaginous Chlorella sp. by organoclays

► Mg, Al, and Ca-backboned organoclays were synthesized. ► Microalgae harvesting efficiency was achieved ∼100% above 0.6 g/L treatment. ► Al and Mg-backboned organoclays were maintained a neutral pH. ► Organoclays could be an effective flocculant agent for microalgae harvesting.