Microcystis aeruginosa removal by in situ chemical oxidation using persulfate activated by Fe2+ ions.

In the present study, the feasibility of using sulfate radicals generated by coupling ferrous ions and persulfate as a transition metal and oxidant, respectively, was investigated for the removal of Microcystis aeruginosa . The results show that the Fe 2+ /S 2 O 8 2− process was effective for the removal of Microcystis aeruginosa and influenced by operating parameters, such as the mass ratio of Fe 2+ and S 2 O 8 2− , persulfate dosage, initial solution pH, and reaction time. The mass ratio of Fe 2+ and S 2 O 8 2− and concentration of persulfate noticeably impacted the Microcystis aeruginosa removal efficiency, with the mass ratio of Fe 2+ and S 2 O 8 2− having a more significant effect than the persulfate dosage. The chlorophyll a removal rate of Microcystis aeruginosa reached 95.38% under the following optimum orthogonal conditions: a mass ratio of Na 2 S 2 O 8 /FeSO 4 of 2:1, a Na 2 S 2 O 8 dosage of 25 mg/L, a pH of 4, and a reaction time of 60 min. Both sulfate and hydroxyl radicals generated from the Fe 2+ -activated persulfate system were responsible for the inhibition of Microcystis aeruginosa cell growth and reproduction through destruction of the cellular structure, degradation of cell inclusions and inhibition of photosynthesis. This study indicated that the application of Fe 2+ -activated persulfate oxidation is a feasible method for treating cyanobacterial blooms. [ABSTRACT FROM AUTHOR]