The kinetics of flocculation and removal of Microcystis aeruginosa by chitosan-modified clays was studied. The efficiency of flocculating and removing of algal cells was greatly improved after the modification of the clays. About 80% of algae cell was removed in 0.5 hour, and 90% in 2 hours, when 11 mg/L modified sepiolite was added. Algae-removal capacities of different clays were all improved to a similar level of >90% at a total loading of 11 mg/L after being modified with chitosan. The efficiency of algae-removing was reduced when the clay loading was larger or smaller than the optimum loading.
