Floatable 3D Sponge@SBC-Induced Dual-Pathway-Activated Persulfate for Microcystis aeruginosa Inactivation

Harmful algal blooms have become a global environmentalproblem.Persulfate-based advanced oxidation processes (PS-AOPs) are a goodmethod for controlling the algal bloom emergency. However, the practicalapplication of PS-AOPs is hindered by the low efficiency and difficultrecovery of the powdered catalysts in actual water. To address thischallenge, a novel floatable 3D sponge@SBC composite (sponge@SBC1-300) was synthesized using biochar through a simple coatingprocess. The sponge@SBC1-300 showed excellent mechanicalstability and catalytic performance in PS-AOPs, achieving 97.7% removalof Microcystis aeruginosa in 250 mins.Good stability and repeatability with a 90.1% removal efficiency afterfour reuse times were observed. In addition, in the actual river andlake water samples, M. aeruginosa canbe effectively inactivated (87.9%). Dual mechanisms, including free-radical(SO4 (& BULL;-), (OH)-O-& BULL;,and O-& BULL;(2) (-)) and nonradical(O-1(2) and electron transfer) pathways, were foundto participate in M. aeruginosa inactivation.Based on the observations of changing cellular morphologies, membranepermeability, and antioxidant system of M. aeruginosa, it was suggested that the generated reactive oxygen species couldinactivate algae cells by attacking cell membranes and damaging theirantioxidant systems. Developinga novel floatable composite catalyst based onpowered biochar with high algae inactivation efficiency, stable mechanicalproperties, and repeatability

Automated summary

Harmful algal blooms have become a global environmental problem. The synthesis of a novel floatable 3D sponge@SBC composite using biochar has shown excellent mechanical stability and catalytic performance in controlling algal blooms. The material also exhibits good repeatability in removing algae.