Removal Of Typical Antibiotics In Water By Functional Carbon

As a new biologically active pollutant,antibiotics in the environment can seriously threaten the ecological balance of microorganisms and human health.Due to the abuse of antibiotics in the aquaculture industry,the low level of sewage treatment and the dependence on antibiotics in the medical field,the problem of used and discharge antibiotics are particularly prominent.In this study,ampicillin(AMP)and norfloxacin(NOF)as target antibiotics,AMP adsorbed by liquid nitrogen low temperature modified carbon material(LNM-CM)and NOF catalyzed by carbon-based composite photocatalysts(ZnO/ZnS@BC).The main research contents and results are as follows:(1)In this experiment,LNM-CM and the carbon maternal unmodified by liquid nitrogen(CM)were used to remove AMP from aqueous solution.The material properties of CMs(LNM-CM and CM)were investigated by N2 adsorption-desorption,scanning electron microscopy(SEM)and Fourier transform infrared spectroscopy(FTIR).The adsorption mechanism of AMP on CMs was investigated by adsorption kinetics,adsorption isotherms and adsorption thermodynamics.The results showed that the CMs had the same chemical functional groups,but the LNM-CM increased the specific surface area by 30.3%.At pH 3,CMs had the highest adsorption capacity for AMP,and LNM-CM increased the adsorption capacity of AMP by 16.5%.The adsorption experimental data is consistent with the pseudo second-order kinetics and the Langmuir model.In the synthetic wastewater experiment,the removal rates of AMP by LNM-CM and CM were 92.31%and 86.56%,respectively.After 10 times of recycling,the adsorption removal rate of AMP by LNM-CM was still as high as 69.3%.Therefore,LNM-CM is a good adsorbent for removing antibiotics from water.(2)This experiment investigated the photocatalytic degradation of NOF by ZnO/ZnS@BC under ultraviolet light.The material properties of ZnO/ZnS@BC were studied by SEM and X-ray photoelectron spectroscopy(XPS).The effects of different factors(pH,catalyst loading,catalyst amount,different ions)on degradation of NOF by ZnO/ZnS@BC were studied.The quenching experiment was used to investigate the degradation mechanism of NOF by ZnO/ZnS@BC.The results show that we have successfully load photocatalyst on biochar,and the composition of the composite photocatalyst is ZnO and ZnS.At a pH of 7 and a loading of ZnO/ZnS of 100%,the degradation rate of NOF by ZnO/ZnS@BC was as high as 95%within 3 hours.Quencher experiments show that ·O2-,·OH-and h+ have different degrees of contribution to NOF degradation,and the order of strength is as follows:·02->·OH->h+.After five cycles of catalyst recovery,the degradation rate of NOF is still as high as 78%.Therefore,ZnO/ZnS@BC is a safe green catalytic material used for practical antibiotic wastewater purification,and has great application prospects in wastewater treatment.