Study On The Structure And Adsorption Performance Of Hierarchical Pore Complex Oxides Under Plant Template

Due to its larger specific surface area,special morphology and better mid-and low-temperature activity,multi-channel composite oxides are widely used in the treatment of pollutants.The natural biological template has the characteristics of multi-level,multi-dimensional,multi-component ordered structure and morphology,which provides a new method for the construction of metal oxide morphology,enriches the metal oxide structure,and expands its application range.In this paper,the biological template is combined with the hydrothermal synthesis method and the dipping method to prepare the multi-stage porous composite oxide,and use this as an adsorbent to investigate its removal performance of sulfonated lignite in the adsorbed oilfield sewage.And through SEM,XRD,N₂adsorption-desorption,FT-IR,TG-DTA and other characterization methods,the morphology,phase structure,pore size and other physical and chemical properties of the sample were analyzed,and the relationship between the structure of the adsorbent and its adsorption performance was preliminarily discussed.Using filter paper as a template,magnesium nitrate and aluminum nitrate as precursor fluids,and urea as precipitating agents,a biomorphic multi-porous composite oxide was synthesized by a hydrothermal method.The analysis results show that the material replicates the three-dimensional network structure of the filter paper fibers,and the metal oxide nanosheets are evenly distributed on the surface of the filter paper fibers.The N₂adsorption-desorption analysis showed that the specific surface area of the biological composite oxide can reach 178.84 m²/g.It shows good adsorption performance for sulfonated lignite.When the temperature is 298 K,the amount of adsorbent is 0.3 g/L,the p H of the adsorption solution is 7,the saturated adsorption capacity of sulfonated lignite by biological complex oxidation can reach 664.8 mg/g.Through the analysis of adsorption kinetics and thermodynamics,the adsorption isotherm in the adsorption process conforms to the Langmuir model;the kinetic adsorption process conforms to the pseudo-second-order kinetic model;the value of?H during the adsorption process is 179.43 KJ/mol;the value of?S is 630.67 J/(mol^-1?K^-1);?G values are-8.51,-11.66,-14.81 KJ/mol,and the absolute value increases with the increase of reaction temperature in the adsorption process,indicating that the process is an endothermic reaction and can proceed spontaneously.The regeneration performance results show that the material has good adsorption stability.Using loofah pulp as a template,magnesium nitrate and aluminum nitrate as precursor fluids,and urea as precipitating agents,a biomorphic multi-porous composite oxide was synthesized by a hydrothermal method.Analysis shows that the material replicates the network fiber structure of loofah flesh well.The N₂adsorption-desorption analysis showed that the specific surface area of the biological composite oxide can reach 241.56 m²/g.It shows good adsorption performance for sulfonated lignite.When the temperature is 298K,the amount of adsorbent is 0.27 g/L,and the p H of the adsorption solution is 7,the saturated adsorption capacity of sulfonated lignite by biological complex oxidation can reach 735.42mg/g.Through the analysis of adsorption kinetics and thermodynamic properties,the adsorption isotherm in the adsorption process conforms to the Langmuir model;the kinetic adsorption process conforms to the pseudo-second-order kinetic model;the?H during the adsorption process is 82.12 KJ/mol;the?S value is 281.13 J/(mol^-1?K^-1);?G are-8.558,-11.35,-14.18 KJ/mol,the absolute value of which increases with the increase of the reaction temperature of the adsorption process,indicating that the process is an endothermic reaction and can proceed spontaneously.The regeneration performance results show that the material has good adsorption stability.Using cotton as the template and magnesium acetate tetrahydrate as the precursor body fluid,biomorphic multi-porous Mg O was synthesized by the dipping method.The analysis showed that the material replicated the long tube fiber structure of absorbent cotton very well.N₂adsorption-desorption analysis shows that the specific surface area of biological Mg O can reach 90.73 m²/g,and it shows good adsorption performance for sulfonated lignite.At a temperature of 298 K,the amount of adsorbent is 0.5 g/L,and the p H of the adsorption solution is 3,the saturated adsorption capacity of biological Mg O on sulfonated lignite can reach 199.83 mg/g.The adsorption process is obtained through the analysis of adsorption kinetics and thermodynamics.The mid-adsorption isotherm conforms to the Langmuir model;the kinetic adsorption process conforms to the quasi-second-order kinetic model;the?H during the adsorption process is 179.43 KJ/mol;the value of?S is 230.88 J/(mol^-1?K^-1);the values of?G are-4.35,-7.18,-8.94 KJ/mol,and the absolute value increases with the increase of reaction temperature in the adsorption process,indicating that the process is an endothermic reaction and can proceed spontaneously.The regeneration performance results show that the material has good adsorption stability.