Titanium dioxide nanoparticles as carrier facilitate bioaccumulation of phenanthrene in marine bivalve, ark shell (Scapharca subcrenata)

To evaluate the impact of titanium dioxide nanoparticles (nTiO(2)) on the uptake of hydrophobic organic chemicals by marine bivalves, we conducted a comparative bioaccumulation study by exposing clam, Scapharca subcrenata, to phenanthrene (Phe) in the presence and absence of nTiO(2). The large surface area of nTiO(2) resulted in adsorption of co-existing Phe in aqueous solution to form nTiO(2)-Phe complexes. Accumulation of nTiO(2) was not observed in clams at exposed concentration (500 mu g/L) in this study. However, enhanced uptake of Phe by clams was observed in the presence of nTiO(2), with k(u) and BAFs values being 2 and 1.7 times higher than that of Phe alone, respectively. The enhanced uptake can be explained by ingestion of nTiO(2)-Phe complexes into the gut and subsequent desorption of Phe there. Therefore, nTiO(2) as a carrier facilitated the uptake of Phe by marine bivalves. (C) 2014 Elsevier Ltd. All rights reserved.