Ceramsite sand and lime modified lake bottom sediments coupled with potassium ferrate pre-oxidation as emergency control of Microcystis aeruginosa blooms

Abstract This study mainly focused on developing an emergency control of Microcytic aeruginosa blooms through efficient algae precipitation agent (CLS) made by ceramsite sand and lime modified lake bottom sediments coupling with potassium ferrate pre-oxidation. SEM, BET, XRD were used to characterize CLS. CLS had a well-developed pore structure, the specific surface area changed from 13.759 m2/g to 25.765 m2/g. We studied the effects of algae density, sedimentation time, initial pH, different algae growth periods, and the addition of potassium ferrate on the algae control of the CLS. The results showed that CLS could adapt to the large concentration change of Microcystis aeruginosa water and with a good settlement effect under the condition of pH 6.0 to 6.5. The sedimentation time for the most effective algae control was 30 min. The algal control efficiencies of Microcystis aeruginosa in the logarithmic phase and the stable phase were higher compared to lag phase and decline phase. Compared than when simply used the CLS for the sedimentation process, the potassium ferrate could significantly reduce the amount of CLS. The process conditions of CLS coupled potassium ferrate pre-oxidation process (Fe-CLS) were optimized by Response surface methodology (RSM). The simulated algal control experiment showed that the algae precipitant agent had no significant impact on the safety of water bodies.