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Nanowastes and the environment: Using mercury as an example pollutant to assess the environmental fate of chemicals adsorbed onto manufactured nanomaterials
Author(s) -
Gao Jie,
Bonzongo JeanClaude J.,
Bitton Gabriel,
Li Ying,
Wu ChangYu
Publication year - 2008
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1897/07-282.1
Subject(s) - environmental chemistry , pollutant , mercury (programming language) , nanomaterials , bioavailability , chemistry , leaching (pedology) , effluent , environmental science , nanotechnology , environmental engineering , materials science , organic chemistry , soil water , soil science , biology , programming language , bioinformatics , computer science
Emerging nanotechnologies hold great promise for creating new means of detecting pollutants, cleaning polluted waste streams, and recovering materials before they become wastes, thereby protecting environmental quality. Studies focusing on the different advantages of nanoscience and nanotechnology abound in the literature, but less research effort seems to be directed toward studying the fate and potential impacts of wastes that will be generated by this technology. Using a combination of biogeochemical and toxicological methods, we conducted a preliminary investigation of the potential environmental fate of Hg as an example pollutant bound to nanomaterials used in treatment of gas effluents. Methylation of Hg sorbed onto SiO 2 ‐TiO 2 nano‐composites was used as a proxy for Hg bioavailability to sedimentary microorganisms, and the FluoroMetPLATE™ assay was used to assess the toxicity of both virgin and Hg‐loaded SiO 2 ‐TiO 2 nanocomposites. Our results show that the bioavailability of Hg sorbed onto SiO 2 ‐TiO 2 nanocomposites to sedimentary microorganisms is pH dependent, with decreasing reaction rates as the pH increases from 4 to 6. Toxicity tests conducted using liquid extracts obtained by leaching of Hg‐loaded SiO 2 ‐TiO 2 nanocomposites with the synthetic precipitation leaching procedure solution showed an average inhibition of 84% (vs 57% for virgin SiO 2 ‐TiO 2 nanocomposites). These results suggest that Hg sorbed onto engineered nanoparticles could become bioavailable and toxic if introduced into natural systems. Accordingly, studies focusing on the environmental implications of nanomaterials should include determination of the fate and impacts of pollutants that enter the environment bound to engineered nanomaterials.