Noyma Natalia P, de Magalhães Leonardo, Miranda Marcela, Mucci Maíra, van Oosterhout Frank, Huszar Vera L M, Marinho Marcelo M, Lima Eduardo R A, Lürling Miquel
Laboratory of Ecology and Physiology of Phytoplankton, Department of Plant Biology, University of Rio de Janeiro State, Rio de Janeiro, Brazil.
Aquatic Ecology & Water Quality Management Group, Department of Environmental Sciences, Wageningen University, Wageningen, The Netherlands.
PLoS One. 2017 Jun 9;12(6):e0178976. doi: 10.1371/journal.pone.0178976. eCollection 2017.
Cyanobacteria blooms are a risk to environmental health and public safety due to the potent toxins certain cyanobacteria can produce. These nuisance organisms can be removed from water bodies by biomass flocculation and sedimentation. Here, we studied the efficacy of combinations of a low dose coagulant (poly-aluminium chloride-PAC-or chitosan) with different ballast compounds (red soil, bauxite, gravel, aluminium modified zeolite and lanthanum modified bentonite) to remove cyanobacterial biomass from water collected in Funil Reservoir (Brazil). We tested the effect of different cyanobacterial biomass concentrations on removal efficiency. We also examined if zeta potential was altered by treatments. Addition of low doses of PAC and chitosan (1-8 mg Al L-1) to the cyanobacterial suspensions caused flock formation, but did not settle the cyanobacteria. When those low dose coagulants were combined with ballast, effective settling in a dose-dependent way up to 99.7% removal of the flocks could be achieved without any effect on the zeta potential and thus without potential membrane damage. Removal efficacy was influenced by the cyanobacterial biomass and at higher biomass more ballast was needed to achieve good removal. The combined coagulant-ballast technique provides a promising alternative to algaecides in lakes, ponds and reservoirs.
由于某些蓝藻能产生强效毒素，蓝藻水华对环境健康和公共安全构成威胁。这些有害生物可通过生物量絮凝和沉淀从水体中去除。在此，我们研究了低剂量混凝剂（聚合氯化铝 - PAC或壳聚糖）与不同压载化合物（红土、铝土矿、砾石、铝改性沸石和镧改性膨润土）组合从巴西富尼尔水库采集的水中去除蓝藻生物量的效果。我们测试了不同蓝藻生物量浓度对去除效率的影响。我们还研究了处理是否会改变zeta电位。向蓝藻悬浮液中添加低剂量的PAC和壳聚糖（1 - 8 mg Al L-1）会导致絮凝物形成，但无法使蓝藻沉淀。当这些低剂量混凝剂与压载物结合时，可实现有效沉淀，絮凝物去除率高达99.7%，且对zeta电位没有影响，因此不会对膜造成潜在损害。去除效果受蓝藻生物量影响，生物量越高，需要更多压载物才能实现良好的去除效果。混凝剂 - 压载物组合技术为湖泊、池塘和水库中的除藻剂提供了一种有前景的替代方案。
