title: Soil-based treatments of mechanically collected cyanobacterial blooms from Lake Taihu: efficiencies and potential risks.
abstract: In China, mechanical collection of cyanoblooms followed by soil-based treatments has been widely used as emergency strategies in many eutrophicated freshwaters. This study was to evaluate both efficiencies and potential risks of typical soil-based technologies. Results from this study indicated that over 90% of cyanobacterial biomass and 96% of dissolved microcystins (MCs) could be restrained in soils via three-level systems, which were much better than single-level systems. High concentrations of MCs, ranged from 65 to 276 ng g⁻¹ and from 2.12 to 6.6 ng g⁻¹, were found in soils around treatment systems and croplands, respectively. In the soil solutions, MCs ranged from 0.35 to 2.0 μg L⁻¹, showing a potentially high leaching risk. In the samples from shallow groundwater near the treatment systems, MC concentrations were detected as high as 1.2 μg L⁻¹. Moreover, bioaccumulations of MCs varied between 22 and 365 μg kg⁻¹, and 19-222 μg kg⁻¹ were found in 13 kinds of crops and 7 kinds of wild grass, respectively. Our results indicated for the first time that current soil-based technologies were effective but could pose potential environmental, ecological, and public health risks. Further improvements of these technologies were also proposed based on our findings.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Yunlu
authors.initials: Y
authors.lastname: Jia
authors.forename: Enhua
authors.initials: E
authors.lastname: Li
authors.forename: Shuang
authors.initials: S
authors.lastname: Zhao
authors.forename: Qichao
authors.initials: Q
authors.lastname: Zhou
authors.forename: Liming
authors.initials: L
authors.lastname: Liu
authors.forename: Lirong
authors.initials: L
authors.lastname: Song
mesh_terms: D002681:China; D018556:Crops, Agricultural; D000458:Cyanobacteria / Q000302:isolation & purification*; D004784:Environmental Monitoring; D052918:Environmental Restoration and Remediation; D005068:Eutrophication; D060587:Groundwater / Q000737:chemistry; D006262:Health; D060106:Lakes / Q000382:microbiology*; D055595:Mechanical Phenomena; D052998:Microcystins / Q000302:isolation & purification; D010839:Phytoplankton / Q000254:growth & development; D006109:Poaceae / Q000737:chemistry; D018570:Risk Assessment; D012987:Soil / Q000737:chemistry*; D012996:Solutions; D014197:Trees / Q000737:chemistry
chemical_list: D052998:Microcystins; D012987:Soil; D012996:Solutions