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Title of Talk:
The fate, transport, transformation and toxicity of manufactured nanomaterials in drinking water
Abstract of Talk:
Research Category and Sorting Code: Exploratory Research to Anticipate Future Environmental Issues (2004-STAR-A1)
Title: The fate, transport, transformation and toxicity
of manufactured nanomaterials in drinking water
Investigators: Drs. 1Paul Westerhoff, 1Yongsheng Chen, 1John Crittenden, and 2David Capco
Institution: 1Department of Civil and Environmental Engineering and 2Department of Biology Arizona State University, Tempe, AZ 85287
Project Period: Sept. 1, 2004 – Aug. 31, 2007
Project Cost: $455,000 ($335,000 from USEPA and $120,000 from ASU matching funds)
Objectives. Although the current market for nanomaterials is small and their concentration may not be high enough in the environment to cause human health or environmental problems, this market is increasing rapidly and the discharge of nanomaterials to environment in the near future could be significant as manufacturing costs decrease and new applications are discovered. The accumulation of nanomaterials in cells may have significant environmental and human impacts. However, at present, very little is known about the fate, transport, transformation and toxicity of these man-made nanomaterials in the environment. The objectives of this project are: 1) to characterize the fundamental properties of nanomaterials in aquatic environments; 2) to examine the interactions between nanomaterials and toxic organic pollutants and pathogens (viruses); 3) to evaluate the removal efficiency of nanomaterials by drinking water unit processes; 4) to test the toxicity of nanomaterials in drinking water using cell culture model system of the epithelium. This study considers the physical, chemical, and biological implications of nanomaterial fate and toxicity in systems that will provide insight into the potential for nanomaterials to be present and of health concern in finished drinking water.
Approach. A multidisciplinary approach is proposed that includes experiments to identify fundamental uniqueness of nine (9) nanomaterial properties and toxicity and quite applied experiments aimed directly at understanding the fate and reactions involving nanomaterials in drinking water treatment plants. Advanced nanomaterial characterization techniques will be employed to determine the size distribution, concentration, and zeta potential of nanomaterials in buffered distilled water and model waters representative of raw drinking water supplies (anions, cations, NOM). Adsorption of dissolve pollutants (anions, metals, range of synthetic organic chemicals) and NOM are proposed to quantify the potential for nanomaterials to transport such compounds, and be transformed by the compounds (e.g., aggregation, change in zeta potential). Coagulation processes will be studied by compressing the electric double layer of nanomaterials, and exposing nanomaterials to alum coagulations, using mono- and heterodisperse solutions; comparable filtration work will also be conducted. Adsorption of virus onto nanomaterials and subsequent disinfectant shielding will be studied. Toxicity screening will include toxicity of nanomaterials on several cell lines selected to mimic oral ingestion routes in drinking water.
Expected Results. The proposed work will provide fundamental information about the fate, transport and transformation of nanomaterials in the drinking water resources and the first evidence that such nanomaterials can or cannot be removed by conventional drinking water treatment processes. An improved assessment will be developed for the potential exposure risks of nanomaterials in drinking water. This research would ultimately provide essential information that would support policy and decision-making regarding handling, disposal, and management of nanoscale materials in commerce, manufacturing and the environment.
Keywords: Fate, Transport, Toxicity, Manufactured Nanomaterials, Drinking water