Effects Of Mental Oxide Nanoparticles In Sediment On Ecotoxicity Of Persistent Toxic Substances In Bellamya Aeroginosa

Nanoparticles（NPs）will be inevitably released into aquatic environment due to its widespread application.The unique physicochemical properties of NPs potentially alter the ecotoxicity of other persistent toxic substances（PTS）coexisting with NPs.Sediments as repository of PTS in aquatic ecosystem.However,the investigation concerned about interaction between NPs and PTS in sediments is scarce at present.In this research,in the presence of titanium dioxide（TiO₂-NPs）and aluminum oxide nanoparticles（Al₂O₃-NPs）,the effects of Cd and 2,2’,4,4’-tetrabromodiphenyl ether（BDE-47）on the key component of antioxidant defense system,superoxide dismutase（SOD）,lipid peroxidation index malondialdehyde（MDA）and phaseⅡbiotransformation enzyme glutathione-S-tansferase（GST）in the hepatopancreas of Bellamya aeroginosa were investigated by applying chronic sediment bioassay to assess the ecotoxicological effects of PTS in presence of NPs,and explore the ecotoxicity mechanism,attempting to provide scientific basis for ecological risk management of NPs.The results indicated,the hepatopancreas oxidative stress only caused at high content of TiO₂-NPs(10 mg·g^-1).At medium and high Cd concentration(25、100μg·g^-1),the ecotoxicity of Cd raised significantly in presence of non-toxic Al2O3-NPs and TiO₂-NPs,and TiO₂-NPs have more effect on Cd than TiO₂-NPs,due to the interaction between NPs and Cd.With the increase of concentration of TiO₂-NPs,significantly enhance the ecological toxicity of Cd by the dose effect of TiO₂-NPs in the different concent of TiO2-NPs combined with Cd.At medium and high BDE-47 concentration(500、2000μg·g^-1),the ecotoxicity of Cd raised significantly in presence of non-toxic Al₂O₃-NPs and TiO₂-NPs,and TiO₂-NPs have more promotional effect on ecotoxicity of Cd than Al₂O₃-NPs.Ecotoxicity of BDE-47 combined with different concent of TiO₂-NPs possess significant dose effect.The ecotoxicity of BDE-47 enhanced significantly with increase of concentration of TiO₂-NPs.The effects of ecotoxicology concern combined contamination with NPs and PTS in sediments influenced by many factors,such as the type and content of NPs and PTS.Therefore,evaluating the potential ecological risk of NPs,multi-factor is needed to consider.The resort of this research has important theoretical significance and practical value to reasonable estimate ecotoxicity risk of combined contamination with NPs and PTS in sediments,and developed the bioassay methods of Bellamya aeroginosa.It also provided risk management of NPs with scientific basises and decision references.