Enhanced accumulation of arsenate in carp in the presence of titanium dioxide nanoparticles

In this study adsorption of arsenic (As) onto TiO2 nanoparticles and the facilitated transport of As into carp (Cyprinus carpio) by TiO2 nanoparticles was examined. Adsorption kinetics and adsorption isotherm were conducted by adding As(V) to TiO2 suspensions. Facilitated transport of As by TiO2 nanoparticles was assessed by accumulation tests exposing carp to As(V) contaminated water in the presence of TiO2 nanoparticles. The results showed that TiO2 nanoparticles had a significant adsorption capacity for As(V). Equilibrium was established within 30 min and the isotherm data was described by Freundlich isotherm. The K-F and 1/n were 20.71 mg/g and 0.58, respectively. When exposed to As(V)-contaminated water in the presence of TiO2 nanoparticles, carp accumulated considerably more As, and As concentration in carp increased by 132% after 25 days exposure. Considerable As and TiO2 accumulated in intestine, stomach and gills of the fish, and the lowest level of accumulation was found in muscle. Accumulation of As and TiO2 in stomach, intestine and gills are significant. Arsenic accumulation in these tissues was enhanced by the presence of TiO2 nanoparticles. TiO2 nanoparticles that have accumulated in intestine and gills may release adsorbed As and As bound on TiO2 nanoparticles which cannot be released maybe transported by TiO2 nanoparticles as they transferred in the body. In this work, an enhancement of 80% and 126% As concentration in liver and muscle after 20 days of exposure was found.