Date of Award

5-2014

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Environmental Toxicology

Advisor

Dr. Stephen Klaine

Committee Member

Dr. Peter van den Hurk

Committee Member

Dr. Tanju Karanfil

Abstract

The introduction of carbon nanomaterials into the environment has increased exponentially in the last decade, causing environmental as well as health concerns. One concern is the interaction that such nanomaterials have with the biota in the aquatic ecosystem and the direct and indirect toxic effects that may result. Previous research has documented a positive influence of natural organic matter (NOM) on the stability of carbon nanotube (CNTs) suspensions in surface waters. Further, research has quantified the ability of these carbon nanomaterials to adsorb aquatic contaminants such as polycyclic aromatic hydrocarbons (PAHs). Though both CNTs and PAHs can co-occur in wastewater treatment effluents few studies have investigated the bioavailability of these adsorbed PAHs to fish. The goal of this research was to characterize the bioavailability of fluoranthene (FLU) adsorbed to suspended muliwalled-carbon nanotubes (MWNTs) in a solution containing NOM. Results indicated that while NOM was critical for producing stable MWNT suspensions, it did not influence the bioavailability of FLU to P. promelas in the absence of MWNTs. Adsorption isotherms indicated that NOM significantly influenced the adsorption of FLU to MWNTs. P. promelas were exposed for 16 hrs in moderately hard water (MHW) containing only FLU, FLU in the presence of different concentrations of NOM, and FLU adsorbed to MWNTs in the presence of NOM. Bioavailable FLU was quantified in each exposure through bile analysis using a fluorescence microplate reader. Results indicated that 2 mg/L NOM as dissolved organic carbon (DOC) were sufficient to produce a stable MWNT suspension. The bioavailability of FLU was significantly reduced in the presence of this suspension. Through comparing the concentration of FLU metabolites in the bile to the concentration of FLU added to MWNT and DOC solutions we were able to quantify the relative bioavailability of FLU adsorbed to MWNTs. Results indicate that approximately 60-90% of the FLU was adsorbed to the MWNTs and that adsorbed FLU was not bioavailable to P. promelas.

Share

COinS