Study On Aquatic Biological Toxicology Of Titanium Dioxide Nanoparticles

Along with the rapid development of nanotechnology, more andmore nanomaterials are widely applied to industry, agriculture and everyaspect of our life. Because of nanomaterials have many differentphysicochemical properties comparing with their bulk counterparts, it isurgent to study and estimate the behavior and biology effects of NPs.Nano-TiO₂is a very important inorganic material and the release of TiO₂nanoparticles into aquatic systems is inevitable as more and moreapplications in environmental protection, cosmetics, paints and so on. Theaquatic biological effects can not be ignored as caused the exposure ofaquatic organisms.In this paper, we used nano-sized TiO₂as the research object and M.aeruginosa and zebrafish as the exposure objects to investigate thebiotoxicological effeets of nano-sized TiO₂. The adsorption behavior ofCd and Cu onto TiO₂nanoparticles were studied; the effect of differentconcentrations of nano–TiO₂and nano–TiO₂with the heavy metal on algae growing in the aquatic environment were investigated; thebioaccumulation of nano–TiO₂and the facilitated transport of the heavymetal Cu were investigated; also the growth and development effects ofzebrafish before and after photocatalysis of nano–TiO₂were studied. Theresults demonstrated that the adsorption processes of Cd and Cu were fast;Nano–TiO₂can promote the growth of algae at low concentrations (0⁵0mg·L^-1), but the rate was inhibited when the concentrations of nano–TiO₂were greater than50mg·L^-1in a pattern of dosage effect. However, as thepresence of nano–TiO₂, the toxicity caused by heavy metals was reducedsignificantly because of the adsorption of nano–TiO₂to heavy metals;nano–TiO₂were significantly accumulated in the zebrafish and facilitatedbioaccumulation of Cu into zebrafish were observed in the presence ofTiO₂nanoparticles; No obvious growth affect on zebrafish embryo wasseen when exposed to nano–TiO₂, but fallen survival and hatching ratesand abnormal development of zebrafish embryo were seen when exposedto nano–TiO₂after photocatalysis. So, the ecological toxicity andenvironmental effects of nano–TiO₂should not be neglected, indeed, thebiological effects of nanomaterials should be considered concurrentlywith other environmental pollutants.