Phytotoxicity And Distribution Of CuO Nanoparticles In Flooding Microcosms

With the rapid development of nanotechnology,nanomaterials are widely used in industrial and consumer goods production and will inevitably be discharged into the environment.The unique structure and nature of nanomaterials can easily produce toxic effects on microorganisms,plants and animals.Nanoparticles may be absorbed,transported and accumulated by plants,and ultimately through the food chain to harm animals and human health.Therefore,in order to scientifically assess the safety of nanomaterials and environmental and health risks,it is necessary to study the migration and transformation of nanomaterials in soil-plant systems.In this paper,CuO nanoparticles were used as the object of study to simulate the natural conditions of CuO nanoparticles entering wetlands.In this paper,the effects of environmental factors on the environmental behavior of nanoparticles in wetlands were studied.The results showed that the CuO nanoparticles were distributed in the upper soil,and the plant uptake of CuO nanoparticles was explored,which provided the theoretical basis for the safety control and ecological risk assessment of nano-materials.For the sustainable development of nano-technology is of great significance.Through the experiment,this paper draws the following conclusions:(1)From the soil and flooding water,Cu2+ treatment resulted in a significant decrease in the pH of soil and flooding water,and CuO nanoparticles and bulkparticles treated with soil and flooding water samples increased slightly,no significant Variety.The TOC levels in the flooding water samples decreased in different degrees,indicating that copper pollution reduced the TOC content in the water.(2)Under the condition of 100 mg·kg-1 CuO nanoparticles and 500 mg·kg-1 CuO bulkparticles stress,the growth of willow was not inhibited but the partial physiological indexes were inhibited,and 100 mg·kg-1 CuO nanoparticles and 500 mg·kg-1 CuO bulkparticles stress affected some physiological indexes of willow but did not affect the normal growth of willow.500 mg·kg-1 CuO nanoparticles and Cu2+ and 100 mg·kg-1 Cu2+stress,the symptoms of willow were significantly consistent with the physiological indexes.Indicating that the toxicity of nanoparticles depends on the concentration of nanoparticles,their own nature and particle size.(3)The results of physiological and biochemical indexes such as chlorophyll content,photosynthesis,chlorophyll fluorescence,antioxidant system and osmotic adjustment substances of willow under different treatments showed that the toxicity of 500 mg·kg-1 Cu2+ on willow was the most serious.The toxic effect of CuO nanoparticles is related to its concentration,and the toxicity of CuO bulkparticles is less than that of CuO nanoparticles.(4)Under the same copper concentration(500 mg·kg-1),he content of Cu in the soil treated with CuO nanoparticles and bulkparticles was significantly lower than that of Cu2+,and the translocation coefficients of willow were different under different treatments.Indicating that healthy willow of Cu enrichment and strong transport capacity.