Study On Synthesis And Application Of Metallic Nanoparticles In Organics Degradation And Disinfection

In recent years,organic pollutants and pathogenic microorganisms in water have received widespread attention.With the development of science,metal nanomaterials have been widely used in various aspects of environmental protection due to their superior performance,including sterilization and organic degradation.The traditional synthesis methods of metal nanomaterials include physical methods and chemical methods.Both of these methods have certain defects,such as high cost and easy to cause secondary pollution.Therefore,there is an urgent need to develop an efficient and environmentally friendly metal nanomaterial preparation method,and further expand.Its application in organic degradation methods and sterilization.Drugs and personal care products are emerging environmental pollutants.Based on palladium nanoparticles and natural clay minerals,the formation of in-situ hydrogen peroxide advanced oxidation system and the efficient degradation of carbamazepine had been achieved.Palladium nanoparticles catalyzed the interaction between formic acid and oxygen to generate hydrogen peroxide in situ,and then interacted with the iron in the non-precipitate to form a Fenton-like system.When the concentration of palladium nanoparticles was 1 g/L,the concentration of nitrite was 1g/L,the concentration of formic acid was 20 mM,and the pH was 3.0,the removal efficiency of carbamazepine was close to 100%after 1 h of reaction.The results of oxidant removal experiments showed that hydroxyl radicals were the only active oxygen radicals in the reaction.We developed a new method for the biosynthesis of copper nanoparticles using Shewanella loihica PV-4 biological method.It was found that Shewanella loihica PV-4,through its own metabolism and other life activities,reduced Cu???to elemental copper and formed a small metal particles.At the initial Cu???concentration of 1 mM,Shewanella loihica PV-4 concentration was OD₆₀₀=2,and the temperature was 30?,the removal efficiency of Cu???reached 85.1%after 120h reaction.Through analysis,it could be known that the process of bioreduction of Cu???by Shewanella loihica PV-4 was both intracellular and extracellular,and the latter was predominant.The copper nanoparticles were physically characterized and the copper nanoparticles were mainly distributed at 10-16 nm and identified as zero-valent copper.The bactericidal properties of microbially synthesized copper nanoparticles were explored.After 12 h of reaction at an initial concentration of 10⁵ CFU/mL and a copper nanoparticle concentration of 100?g/mL,the E.coli bactericidal efficiency reached 82.3%.The chemical oxidation of hydrogen peroxide radicals produced by copper nanoparticles causes cell damage.Through correlation analysis,it was concluded that both cell membrane and cytoplasm components were destroyed,and lipid peroxidation and DNA damage were the main influencing factors.In summary,this study uses the advanced oxidation technology system based on palladium nanoparticles has a good degradation of carbamazepine and uses biological methods to synthesize copper nanoparticles and found that it has good antibacterial properties against E.coli.The results provide new directions and ideas for the efficient treatment of trace organics and pathogenic microorganisms in water treatment and reuse,and provide theoretical and technical basis for the application of nanomaterials to the environment.