Study On The Adsorption Behavior Of Persistent Biomass Functional Materials On Levofloxacin

The national production of persimmons exceeds 2 million tons/year,and Gongcheng County,Guilin City,Guangxi Zhuang Autonomous Region is the main persimmon growing area in the region.In the process of persimmon cultivation,a large number of immature green persimmon fruits are discarded due to the need to increase production.Persimmon processing food factories also produced a large amount of waste persimmon residue during further processing,which cannot be used rationally and were directly discarded.Persimmon tannin functional material can be extracted from waste green persimmon fruit and biochar material can be obtained from persimmon residue,which were in line with the idea of"waste to waste"agricultural waste development and utilization.Sarsin antibiotics are important anti-infective drugs,which are widely used to treat infectious diseases in livestock and aquaculture.In addition to human infections,and were common harmful contaminants in the water environment,and were at the forefront of all antibiotic contaminant detection and monitoring.Sarsaparilla antibiotics are highly toxic to aquatic species and their presence in large quantities in the aquatic environment can lead to an increased risk of drug-resistant bacteria.In this paper,we conducted basic research on adsorbent materials for the pollution control of the sarsin antibiotic,levofloxacin,by combining persimmon tannins extracted from agricultural waste sparse green persimmon fruit with the resulting persimmon residue and other materials to prepare new adsorbent materials for levofloxacin,which solves the problem of agricultural waste utilization and provided a solution to the problem of antibiotic pollution in the water environment.In this study,four biofunctional materials were prepared from persimmon fruit resources and their adsorption behaviors on levofloxacin（LEV）were investigated to lay the foundation for subsequent adsorption studies on other antibiotic species.The main studies are as follows:（1）Preparation of eggshell/persimmon tannin composites（ES/PT）by titanate coupling method,in which waste eggshell powder and persimmon tannin were prepared by titanate compounding to obtain new composites.The addition of eggshell powder material solved the problem of good water solubility of persimmon tannin and its easy loss in aqueous solution,and gave it a porous structure,which further enhanced the adsorption performance of persimmon tannin material.The results showed that the maximum adsorption capacity of the adsorbent was 75 mg/g at a temperature of 313 K,p H=6.0,levofloxacin（LEV）concentration of 15 mg/L,and material dosing of 45 mg.Kinetic studies showed that the adsorption was in accordance with the proposed secondary kinetic process,indicating the presence of both chemical and physical adsorption.（2）Montmorillonite-modified persimmon tannins（MT/PT）were prepared by cross-linking method.The addition of montmorillonite material also solved the problem of good water solubility of persimmon tannins and their easy loss in aqueous solution,and also endowed the material with cation exchange properties,which further increased its adsorption effect on levofloxacin.The results showed that the maximum adsorption capacity of the adsorbent was 113.7 mg/g at a temperature of 313 K,p H=7.0,levofloxacin（LEV）concentration of 30 mg/L,and a material dosage of 25 mg.Kinetic studies showed that the adsorption was in accordance with a proposed secondary kinetic process,with both physical and chemical adsorption.The isothermal model study showed that it was more consistent with the Langmuir model.（3）The waste persimmon residue was burned into biochar by muffle furnace,and then prepared into persimmon residue biochar（PTBAC）after two-stage activation by acid and alkali.Its specific surface area can reach 2377.21 m²/g and possesses fast and efficient adsorption（LEV）capacity.The results showed that the maximum adsorption capacity of the adsorbent reached 588.23 mg/g at a temperature of 313 K,p H=7.0,levofloxacin（LEV）concentration of 90 mg/L,and material dosing of 15 mg.Kinetic studies showed that the adsorption process was consistent with the proposed first-order kinetics,indicating that it was dominated by physical adsorption.The isothermal model study showed that it was more in line with the Langmuir model,with monolayer adsorption dominating.（4）For adsorption material recovery,montmorillonite/persimmon tannin was selected as the base material and the magnetic Fe₃O₄montmorillonite-modified persimmon tannin material（Fe₃O₄/MT/PT）was prepared by hydrothermal method.The optimum coverage rate of Fe₃O₄with MT/PT and its adsorption performance were investigated.There was no change in magnetic properties before and after adsorption,and the specific surface area and pore size further increased,and the adsorbed material in aqueous solution could be recovered by magnetic convenience.The maximum adsorption capacity of the adsorbent was 89.1 mg/g for temperature 313 K,p H=6.0,levofloxacin（LEV）concentration 30 mg/L and material dosing 25 mg.The kinetic study showed that Fe₃O₄/MT/PT was more consistent with the proposed secondary kinetic process,and the isothermal study results for it was more consistent with the Freundilch model.