Marsalek B.,Academy of Sciences of the Czech Republic |
Jancula D.,Academy of Sciences of the Czech Republic |
Marsalkova E.,Academy of Sciences of the Czech Republic |
Mashlan M.,Center for Nanomaterial Research |
And 6 more authors.
Environmental Science and Technology | Year: 2012
Cyanobacteria pose a serious threat to water resources around the world. This is compounded by the fact that they are extremely resilient, having evolved numerous protective mechanisms to ensure their dominant position in their ecosystem. We show that treatment with nanoparticles of zerovalent iron (nZVI) is an effective and environmentally benign method for destroying and preventing the formation of cyanobacterial water blooms. The nanoparticles have multiple modes of action, including the removal of bioavailable phosphorus, the destruction of cyanobacterial cells, and the immobilization of microcystins, preventing their release into the water column. Ecotoxicological experiments showed that nZVI is a highly selective agent, having an EC 50 of 50 mg/L against cyanobacteria; this is 20-100 times lower than its EC 50 for algae, daphnids, water plants, and fishes. The primary product of nZVI treatment is nontoxic and highly aggregated Fe(OH) 3, which promotes flocculation and gradual settling of the decomposed cyanobacterial biomass. © 2012 American Chemical Society.