Biotoxicity Mechanism Of Photocatalysis NiO Nanoparticles In Chlorella Vulgaris

Photocatalytic nanoparticles are used as new materials for reducing environmental pollutants by active oxygen free radicals which produced under UVC irradiation. Therefore, the material will discharge into the aqueous environment finally. Whether the pNPs is harmful to the environment is a problem to be solved urgently.The aims of the study is to research the toxic mechanism of NiO nanoparticles (nNiO) which under UVC irradiation in Chlorella vulgaris. Main research contents and results were as follows:1) The effects of Photocatalytic nNiO on the C. vulgaris were investigated using (OECD201) algae growth inhibition test. The results showed a tendency of a decrease inhibition rate at48h and an increase in Photocatalytic nNiO group at72h were found in this study.2) Significant variations were investigated in the chlorophyll content and chlorophyll fluorescence of C. vulgaris after exposed on photocatalytic nNiO. The chlorophyll content of C. vulgaris reduced significantly, probably suggesting that the PS â…¡ reaction centers of C. vulgaris were damaged in72h, which affected the photosynthesis of chlorella ultimately.3) The nNiO will release more exogenous ROS under UVC irradiation compared to unirradiation. Intracelluar ROS is increased by the exogenous ROS and the SOD activity is elevated at the same time.4) The esterase activity is increased significantly by exposed on photocatalysis nNiO in C. vulgaris at2h. The esterase activity can be used as a biomarker for reaserch the toxicity of pollutants.