title: Removal of Microcystis aeruginosa using hydrodynamic cavitation: performance and mechanisms.
abstract: Algal blooms are a seasonal problem in eutrophic water bodies, and novel approaches to algal removal are required. The effect of hydrodynamic cavitation (HC) on the removal of Microcystis aeruginosa was investigated using a laboratory scale device. Samples treated by HC were subsequently grown under illuminated culture conditions. The results demonstrated that a short treatment with HC could effectively settle naturally growing M. aeruginosa without breaking cells. Algal cell density and chlorophyll-a of a sample treated for 10 min were significantly decreased by 88% andv 94%, respectively, after 3 days culture. Various HC operating parameters were investigated, showing that inhibition of M. aeruginosa growth mainly depended on treatment time and pump pressure. Electron microscopy confirmed that sedimentation of algae was attributable to the disruption of intracellular gas vesicles. Damage to the photosynthetic apparatus also contributed to the inhibition of algal growth. Free radicals produced by the cavitation process could be as an indirect indicator of the intensity of HC treatment, although they inflicted minimal damage on the algae. In conclusion, we suggest that HC represents a potentially highly effective and sustainable approach to the removal of algae from water systems.
authors: School of Environmental Science and Engineering, State Key Laboratory of Control and Resource Reuse, Tongji University, 1239 Siping Road, Shanghai, PR China; The Collaborative Innovation Center of Advanced Technology and Equipment for Water Pollution Control and the Collaborative Innovation Center for Regional Environmental Quality, 1239 Siping Road, Shanghai, PR China. Electronic address: lipan163@hotmail.com.
authors: Pan
authors: P
authors: Li
authors: School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai, PR China.
authors: Yuan
authors: Y
authors: Song
authors: School of Environmental Science and Engineering, State Key Laboratory of Control and Resource Reuse, Tongji University, 1239 Siping Road, Shanghai, PR China; The Collaborative Innovation Center of Advanced Technology and Equipment for Water Pollution Control and the Collaborative Innovation Center for Regional Environmental Quality, 1239 Siping Road, Shanghai, PR China. Electronic address: ysl@tongji.edu.cn.
authors: Shuili
authors: S
authors: Yu
mesh_terms: D002734:Chlorophyll / Q000378:metabolism; D000077194:Chlorophyll A; D005453:Fluorescence; D005609:Free Radicals / Q000737:chemistry; D057446:Hydrodynamics; D046931:Microcystis / Q000166:cytology / Q000254:growth & development / Q000302:isolation & purification* / Q000648:ultrastructure; D009930:Organic Chemicals / Q000032:analysis; D010788:Photosynthesis; D012212:Rheology; D055672:Static Electricity; D018508:Water Purification / Q000379:methods*
chemical_list: D005609:Free Radicals; D009930:Organic Chemicals; D002734:Chlorophyll; D000077194:Chlorophyll A
keywords: Algal removal; Free radical; Hydrodynamic cavitation; Intracellular gas vesicle; Microcystis aeruginosa; Photosynthetic apparatus