The Study On Treatment Of Tetracycline Hydrochloride In Groundwater Of A Pharmaceutical Factory In Jilin Province

As an important part of water resources,groundwater has an important impact on human production and life.With the development of medical and health care,antibiotics in organic pollutants enter the groundwater through various migration routes,which not only cause serious groundwater pollution,but also indirectly endanger human health.Therefore,the removal of antibiotics in groundwater has become a hot research topic.The traditional methods have high cost,poor stability,incomplete treatment,secondary pollution,complicated operating conditions and long processing period when dealing with antibiotic wastewater.Conditions for large-scale promotion.Researchers have adopted more efficient and environmentally friendly photocatalytic technology.The conventional photocatalyst TiO₂has a large band gap and can only be excited by ultraviolet light,so the photocatalytic efficiency is low.Graphite-phase carbon nitride（g-C₃N₄）has a band gap of 2.7 eV,which has attracted much attention in environmental and ecological fields due to its low preparation cost and high stability.As a new type of photocatalytic material,rare earth vanadate exhibits good photocatalytic activity.In this paper,a pharmaceutical factory in Jilin Province was selected as the groundwater pollution investigation area.The pumping investigation was carried out from 8 sampling points,and the organic pollutant-tetracycline hydrochloride was found in the groundwater,and the concentration reached 21.2mg/L.Therefore,tetracycline hydrochloride was used as the target pollutant,and it was photocatalyticly degraded in the laboratory to provide experimental basis for the investigation of organic pollutants in groundwater.In this paper,g-C₃N₄ was used as the substrate,and g-C₃N₄ was modified by semiconductor compounding and photodeposition.X-ray diffraction（XRD）,infrared（FT-IR）,ultraviolet diffuse reflectance（UV-vis）,scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,X-ray photoelectron spectroscopy（XPS）,specific surface area（BET）,fluorescence spectrum（PL）and other methods were used to characterize the photocatalytic material.The tetracycline hydrochloride（TC）was used as the target pollutant and the 500W xenon lamp was used as the light source to study the visible light catalytic degradation of the organic pollutant tetracycline hydrochloride.YbVO₄/g-C₃N₄ composite catalyst was prepared by the combination of ultrasonication and calcination.The sample showed that the spindle-shaped YbVO₄ adhered to the g-C₃N₄nanosheet and formed a heterojunction at the interface,which was beneficial to photogenerated electron cavities.The separation,thereby increasing the photocatalytic activity of the nanomaterial.Degradation experiments show that the composite metal nanomaterial 40%-YbVO₄/g-C₃N₄ has the highest photocatalytic activity.Under the irradiation of 180min xenon lamp,the degradation rate of tetracycline hydrochloride reached78.5%,and after five times of repeatability test,the degradation effect It is still around 72%,which indicates that the composite nanomaterial 40%-YbVO₄/g-C₃N₄ has good photocatalytic activity.Then the PrVO₄/g-C₃N₄ composite catalyst was prepared by the same principle.The sample characterization showed that PrVO₄ was granular and closely attached to the surface of g-C₃N₄ nanosheets.When the loading of PrVO₄ is 20wt%,the photocatalytic activity of the composite metal nanocatalyst is the highest,the degradation rate of tetracycline hydrochloride reaches 88.7%,and after five repetitive tests,the degradation effect on TC is still 85%.Left and right,this indicates that the composite metal nanomaterial 20%-PrVO₄/g-C₃N₄ has good catalytic activity.Finally,Ag/PrVO₄/g-C₃N₄ternarycomposite nanocatalyst was preparedby photodeposition method.The characterization of the sample indicates that the nano silver particles adhere to the surface of the PrVO₄/g-C₃N₄ nanomaterial,and a plasmon resonance effect occurs,which generates more electrons and holes,thereby improving the visible light catalytic activity of the sample.The degradation experiment results show that the composite5%Ag/20%-PrVO₄/g-C₃N₄ has the highest photocatalytic activity,and the degradation rate of TC after 2h reaches 99.5%,which is significantly higher than the PrVO₄/g-C₃N₄ binary.The degradation efficiency of the composite catalyst（88.7%）.After five repetitive tests,the degradation effect on tetracycline hydrochloride was still around 95%.The experimental results show that the successful preparation of XVO₄/g-C₃N₄（X=Yb,Pr）series visible light catalysts provides a reliable experimental basis and good application prospect for the treatment of organic pollutants in groundwater in the investigation area.