Toxicity Of Nano-BiOCl On Pseudokirchneriella Subcapitata-the Effect Of Oxygen Vacancies

In recent years,with the development of science and technology,nanotechnology has been widely used in cosmetics,textiles,drug research,wall coating and many other fields.Nanomaterials will inevitably be discharged into the freshwater environment.How to effectively and accurately evaluate the biological toxicity of nanomaterials is a hot topic in current research.As a primary producer in the water environment,algae play a crucial role in the assessment of eutrophication of water and the safety of the water environment.At the same time,algae are used as model organisms commonly used in environmental toxicology because of their sensitivity,so it is necessary to study the toxic effects of nanomaterials on algae.Based on claw crescent algae?Pseudokirchneriella subcapitata?as the experimental material,studied the oxygen vacancy exists BiOCl-OV and no oxygen defects of nano the toxicity effect of BiOCl,The toxic effects include growth inhibition,chlorophyll content change and oxidative damage of lunula lanceolata.The main research contents and conclusions of this paper are as follows:1.The growth inhibition of two kinds of nano-BiOCl materials on lunula amniocera was correlated with the exposure concentration.At 96 h,the growth inhibition EC₅₀0 value of nano BiOCl-OV on Pseudokirchneriella subcapitata was 4.242 mg·L^-1,which was highly toxic.The toxicity of BiOCl at 96 h-EC₅₀0 was 34.403 mg·L^-1.At 96 h,the inhibition rate of nano BiOCl-OV with a concentration of 40 mg·l^-11 was 93.39%.The inhibition rate of BiOCl with a concentration of 400 mg·L^-11 was 93.65%.2.This experiment also explored the influence of nano-BiOCl exposure on chlorophyll content of Pseudokirchneriella subcapitata.72 h later,the results showed that there was a dose-effect relationship between chlorophyll content and the treatment group.The reason may be that the toxicity of nano-BiOCl damaged the chloroplast structure of Pseudokirchneriella subcapitata and affected its normal physiological function.In addition,agglomeration of nano-BiOCl occurs in the water,covering the Pseudokirchneriella subcapitata,leading to a decrease in the photosynthetic rate of Pseudokirchneriella subcapitata and affecting the chlorophyll content.3.By measuring the effects of oxygen vacancy BiOCl-OV and oxygen deficiency BiOCl on ROS,CAT,SOD and MDA contents of luna amniosa,the effects of oxidative damage of Pseudokirchneriella subcapitata under the stress of two kinds of BiOCl were further explored.The results showed that both kinds of nano-BiOCl would produce oxidative stress response to Pseudokirchneriella subcapitata,which would lead to cell membrane damage or direct cell membrane damage through ROS increase,and eventually lead to cell senescence and death.In summary,nano-BiOCl has certain biological effects on the growth status,chlorophyll synthesis and oxidative damage of Pseudokirchneriella subcapitata.The toxicity of nanomaterials is related to particle size and oxygen vacancy.