Study On The Performance Of Metal Organic Framework And Carbon Nanocomposites For Adsorption Of Antibiotics In Wate

Among many antibiotics,tetracycline（TC）is a class of antibiotics with tetraphene structure.Because of its low production cost and wide antibacterial activity,it has been widely used in animal husbandry and human therapy.Due to metabolism,a large number of TC will be directly discharged from the body through the blood through the kidney into the domestic wastewater.Therefore,it is necessary to study effective methods to remove TC.Metal-organic framework（MOFs）,a novel porous nanomaterial,is a kind of nanomaterial formed by covalent bond connecting organic ligands with metal ions or metal ion clusters.It has the advantages of high specific surface area and high porosity,and has the potential of high performance adsorbent.However,the interaction between water molecules and metal ions.As a result,most MOFs cannot exist stably in water for a long time and are difficult to be applied in water adsorption.MOFs synthesized using high-valence metal ions(such as Zr⁴⁺),such as MOF-525,have been shown to have good water stability due to higher covalent bond strength.However,although the single frame structure of MOF-525 has a large specific surface area,but the adsorption driving force is low,so the adsorption performance needs to be improved.Based on the above background,this paper combines MOF-525 with GO to improve the adsorption performance of MOF-525.The main work is as follows:（1）MOF-525/GO composite was successfully synthesized by solvothermal deposition of MOF-525 on GO sheet structure.The study on the adsorption properties of MOF-525/GO shows that the synergistic effect between MOF-525 and GO increases the adsorption properties 42%by compared with the simple mixture of MOF-525 and GO.In addition,MOF-525/GO can remove about 47%of TC within 2 min,which is much faster than the initial adsorption rate of traditional adsorbents.Kinetics and isotherm studies show that the adsorption process is an exothermic process dominated by chemisorption.Finally,the adsorption mechanism is studied.π-πpacking and hydrogen bond interaction are the main reasons for MOF-525/GO adsorb a large amount of TC,and the complexation between Zr and TC is an important factor for the removal of TC by MOF-525/GO in the short time.（2）Compared with the high specific surface area of MOF-525,the specific surface area of MOF-525/GO is greatly reduced due to aggregation.By further improving the synthesis process,GO was dispersed in copper alginate（Alg-Cu）with three-dimensional structure,and then MOF-525 was grown in situ to obtain Alg-Cu@GO@MOF-525.The specific surface area of Alg-Cu@GO@MOF-525 is up to 807 m²/g,and the effect of aggregation is reduced by the introduction of Alg-Cu.The results show that the adsorption properties of the composites are much higher than those of MOF-525,GO and Alg-Cu.In addition,a variety of organic dye pollutants also has a high dsorption properties.The adsorption experiments with TC as the main research object show that the performance removal rate is as high as 97%of TC when p H is neutral.Under the experimental condition of 45℃,the adsorption performance is the best,and the maximum adsorption capacity is up to 533 mg/g.Kinetics and isotherm studies indicate that the adsorption process is spontaneous and exothermic chemisorption.Pore filling,complexation,π-πpacking,hydrogen bond interaction and chemisorption are considered to be the main causes of adsorption.