Study On The Removal Performance Of Tetracycline Hydrochloride By Modified Graphene Oxide Composite

Tetracycline antibiotics（TCs）are the most common antibiotics in the world.However,TCs are difficult to be metabolized and absorbed by animals,and most of them are excreted into the environment through excrement in the form of parent compounds.They can cause many side effects such as nausea and vomiting,loss of appetite,double infections,affecting bone and tooth growth,etc.It can remain in the water for a long time.New methods of TC degradation include sludge digestion technology,membrane process,advanced oxidation process,hydrolysis process,ultrasonic degradation,low temperature plasma technology and soil infiltration system.Graphene oxide（GO）is a carbon-based nanomaterial widely used for adsorption and catalytic degradation.It has high electron mobility,excellent electrical conductivity,optical transparency and good chemical stability,making it active in adsorption and photocatalysis.The aspect showed excellent performance.Sodium alginate（SA）is a naturally occurring anionic,chain-forming,hydrophilic colloidal heteropolysaccharide with randomly arrangedα-l-guluronic acid（G block）andβ-d-mannuronic acid（M block）residues are linear and unbranched,they are C5-epimers.When divalent metal ions such as Cu²⁺and Fe³⁺exist in the aqueous solution,SA will cross-link with the metal ions to form a gel with a spatial network structure.Based on the above background,the main works of this article are as follows:（1）Prepared copper-loaded copper alginate/graphene oxide（CA/GO）by wet spinning technology,using Fourier transform infrared spectroscopy（FTIR）,scanning electron microscope（SEM）,thermogravimetric analysis（TGA）and specific surface area analysis（BET）characterized the surface morphology and physicochemical properties of the composite material,and carried out an experiment on the removal mechanism in a sodium persulfate（PS）system to simulate a water environment contaminated by tetracycline（TC）.The effects of composite material dosage,PS concentration,p H,temperature,TC initial concentration and different materials on the performance of CA/GO for TC removal were studied.The results showed that the removal rate of CA/GO composite material was 92.68%after 140 min at a temperature of 50℃,a dosage of CA/GO of 0.5 g/L,and an initial concentration of TC of 100 mg/L.Fitting the experimental data to the isotherm model found that the Langmuir isotherm model can better describe the adsorption process,which indicates that the adsorption process is a single layer adsorption that occurs on the homogeneous surface of the material.Recycling experiments found that when the CA/GO material was recycled to the fifth time,the TC removal rate of 100 mg/L was reduced to 57.68%.（2）According to reports,copper metal has symptoms of toxicity to microorganisms and plants,and it is necessary to prevent its ions from leaching out of the catalyst.On the other hand,iron-based activation is practical and cost-effective,with high efficiency,but also has the characteristic effects of relatively non-toxic and naturally abundant iron.The iron-loaded iron alginate/graphene oxide（IA/GO）was prepared by wet spinning process.The effects of composite material dosage,PS concentration,p H,temperature,TC initial concentration and different materials on the performance of CA/GO for TC removal were studied.The results showed that the removal rate of IA/GO composite material was 96.93%after 140 min at a temperature of 50℃,IA/GO dosage of 0.5 g/L,and TC initial concentration of 100 mg/L.The higher the ambient temperature is,the more favorable the removal process is,which indicates that the degradation process is endothermic.The experimental data is more consistent with the Langmuir model,which indicates that the adsorption process is a single layer adsorption that occurs on the homogeneous surface of the material.Five adsorption-desorption cycle experiments on the material found that the removal rate of 100 mg/L TC solution by IA/GO gel filaments can still reach 70.46%,which has good reusability.