| Nowadays,the use of drugs and personal care products(PPCPs)is gradually increasing with the rapid development of cities and the rapid growth of population.The national testing institutions began to detect a small amount of PPCPs from the water sources in the living quarters.This indicates that PPCPs is beginning to harm the water source of human life.NORFloxacin(Norf)is a third generation quinolone antibiotic containing 4-quinolone mother nucleus.After the extensive use of antibiotics,the pollution of antibiotics to the environment will become more serious,and accelerating the spread of antibiotic resistance genes will lead to bacterial mutation and drug resistance.Such a result will only lead to a decrease in the efficacy of antibiotics,and then only increase the use of antibiotics to achieve the original therapeutic effect,which will cause a vicious circle.Therefore,how to remove antibiotics in water environment is very important.In this paper,CdS materials were modified by hydrothermal method,UIO-66-NH2 was prepared,and g-C3N4 was prepared by secondary calcination method,then CdS and the two materials were modified and compounded by oil bath heating and solvothermal method respectively.Two kinds of composite materials,CdS/ UIO-66-NH2 and CdS/ g-C3N4,were prepared,and then the degradation performance of NORF in water was studied in turn,which provided more reference direction and basis for solving antibiotic pollution in water.the water used in the experiment was configured with deionized water.This paper mainly includes the following two aspects:First,due to the increasing dependence of people on antibiotics,the extensive use of antibiotics has brought more and more serious harm to the environment.Although many countries and regions began to control the use of antibiotics in recent years,how to control the environmental pollution caused by antibiotics is still a difficult problem.Therefore,how to remove antibiotics in water environment has become the most concerned problem for researchers.Therefore,how to remove antibiotics in water environment has become the most concerned problem for researchers.In this study,the removal of NORF from water by photocatalysis was explored,and the synthesized CdS/ UIO-66-NH2 was selected as the catalyst.While taking advantage of the excellent photoresponsive ability of CdS,UIO-66-NH2 was selected to prepare the composite material,and the frame structure of MOF material effectively prevented the photocorrosion of CdS and the recombination of photo-generated carriers.According to BET test,UIO-66-NH2 itself has high specific surface area and adsorption performance,so the composite CdS/ UIO-66-NH2 not only integrates the respective properties of the two materials,but also achieves the effect of amplification.In the experimental process,the p H value of the best NORF degradation environment is in the range of 7±0.3.Experimental comparison shows that when the catalyst with 0.1g/L and CdS ratio of 1.5 is used and the solution is at neutral p H,the degradation rate of NORF is the highest within 120 minutes,and it can degrade about 73%.By simulating the anions that may be contained in the actual environmental water,the results show that when the water contains NO3ˉ,Clˉ and HCO3ˉ,the catalyst has certain influence on the degradation effect of NORF.Finally,it is proved that the catalyst has good stability by cyclic experiments.In addition,the degradation mechanism of the catalyst was analyzed.By adding different trapping agents in the NORF removal experiment,the main active substances produced during the degradation of the catalyst can be obtained.Experiments show that CdS/UIO-66-NH2 composite can effectively remove NORF in water.this study provides more evidence for the subsequent removal of NORF antibiotics in water.This work will also provide a potential contribution to the removal of NORF from the environment.Second,Photocatalytic oxidation method has become more and more mature in the research and application of removing pollutants in water.Its principle is to form excited States by using catalysts to absorb electromagnetic radiation in a specific wave band under illumination,and then react chemically with other substances.In this study,CdS/g-C3N4 photocatalyst was prepared by hydrothermal method to explore the degradation effect of norfloxacin antibiotics by photocatalytic oxidation of composite materials.based on the porous lamellar structure of g-C3N4,CdS was dispersed and attached to graphite phase carbon nitride,so as to achieve the purpose of modifying CdS.because of the heterojunction formed by the combination of composite materials,there is synergistic effect between them.It not only improves the generation of photo-generated carriers,but also effectively prevents the photo-corrosion of CdS.The experimental results show that the composite modified catalyst has better photocatalytic degradation effect and stability than pure CdS.In the experimental process,the p H value of the best NORF degradation environment is in the range of 7±0.3.Experimental comparison shows that when the catalyst with 0.1g/L CdS accounting for 40wt% of the total material is used and the p H of the solution is neutral,the degradation time of 120 minutes can reach 76%.By simulating the anions that may be contained in the actual environmental water,the results show that when the water contains NO3ˉ,Clˉ and HCO3ˉ,the catalyst has certain influence on the degradation effect of NORF.In addition,the degradation mechanism of the catalyst was analyzed.By adding different trapping agents in the NORF removal experiment,the main active substances produced during the degradation of the catalyst can be obtained.Experiments show that CdS/g-C3N4 composite can effectively remove NORF in water.this study provides more evidence for the subsequent removal of NORF antibiotics in water.Therefore,this study is of great reference significance for the degradation and removal of NORF. |
PDF Full Text Request