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Anaerobic Toxicity of Cationic Silver Nanoparticles
Citation:
Gitipour, A., S. Thiel, K. Scheckel, AND T. Tolaymat. Anaerobic Toxicity of Cationic Silver Nanoparticles. D. Barceló Cullerés, and J. Gan (ed.), SCIENCE OF THE TOTAL ENVIRONMENT. Elsevier BV, AMSTERDAM, Netherlands, 557-558:363-368, (2016).
Impact/Purpose:
The current study aims at investigating the effect of AgNPs on the anaerobic degradation process in simulated environmental systems.
Description:
The microbial toxicity of silver nanoparticles (AgNPs) stabilized with different capping agents was compared to that of Ag+ under anaerobic conditions. Three AgNPs were investigated: (1) negatively charged citrate-coated AgNPs (citrate-AgNPs), (2) minimally charged polyvinylpyrrolidone coated AgNPs (PVP-AgNps) and (3) positively charged branched polyethyleneimine coated AgNPs (BPEI-AgNPs). The AgNPs investigated in this experiment were similar in size (10-15 nm), spherical in shape, but varied in surface charge which ranged from highly negative to highly positive. While, at AgNPs concentrations lower than 5 mg L-1, the anaerobic decomposition process was not influenced by the presence of the nanoparticles, there was an observed impact on the diversity of the microbial community. At elevated concentrations (100 mg L-1 as silver), only the cationic BPEI-AgNPs demonstrated toxicity similar in magnitude to that of Ag+. Both citrate and PVP-AgNPs did not exhibit toxicity at the 100 mg L-1 as measured by biogas evolution. These findings further indicate the varying modes of action for nanoparticle toxicity and represent one of the few studies that evaluate end-of-life management concerns with regards to the increasing use of nanomaterials in our everyday life. These findings also highlight some of the concerns with a one size fits all approach to the evaluation of environmental health and safety concerns associated with the use of nanoparticles.
