| With the development of industry and agriculture,the pollution of water bodies caused by organic pollutants has become increasingly serious.The problem of organic pollution in water bodies needs to be solved.At present,the methods of degradation organic pollutants can be divided into physical,chemical and biological methods.The physical adsorption method is one of the most important physical treatment methods because of its advantages of simple operation,high adsorption efficiency,and reusability of adsorbate.Porous carbon as a highly effective adsorption material in the water treatment is attracting attention.In this paper,the existing preparation method of the porous carbon material is optimized and integrated,we prepared the porous carbon materials with pore structure and ultra-high specific surface were by freeze-drying technique,carbonization method and chemical activation method.Explore a new method of porous carbon with ultra high specific surface area and pore volume.And its adsorption performance in-depth study,specifically divided into the following aspects:1.The synthesis of porous carbon materials:In this paper,the polymer material polyvinylpyrrolidone(PVP)is used as a raw material by freeze-drying,combined with a combination of high-temperature carbonization and chemical activation,and through the preparation and freeze-drying process of the precursor solution,the pre-oxidation process of the precursor porous carbon material,the high-temperature carbonization process of the precursor material and the chemical activation process of the porous carbon,a composite type in which micropores,mesopores and macropores are integrated is obtained.Porous carbon material with ultra-high specific surface area(2930.2 m2/g)and pore volume(1.7306 cm3/g).It was characterized by SEM,XRD,IR,TG-DTG,low-temperature nitrogen adsorption-degassing isothermal curve and mercury injection test.It was found that when the precursor concentration was changed,the macroporous structure of the porous carbon was indirectly changed by changing the morphology of the ice stencil;changing the pre-oxidation temperature and time conditions had little effect on the porous carbon;changing the carbonization temperature and the heating rate,finding the carbonization temperature the higher,the slower the heating rate,the more regular the morphology of the porous carbon,and the higher the temperature,the greater the degree of amorphization of the porous carbon;changing the activation time conditions,it was found that the activation process is mainly the process of forming microporous structure,activation time the longer the pore structure of porous carbon,the more developed the pore structure.2.The research on adsorption performance of porous carbon materialsThe adsorption capacity of this porous carbon for methylene blue(MB),methyl orange(MO)and rhodamine B(RB)dyes was systematically studied,and adsorption kinetics equations were fitted for the adsorption results and the adsorption mechanism was inferred.It was found that the adsorption of methylene blue(1212.5 mg/g)and rhodamine B(1125 mg/g)on the porous carbon was mainly electrostatic adsorption,and the adsorption of methyl orange(950 mg/g)was a composite effect;Then,the methylene blue dye was used as an adsorbent and the factors such as the adsorption temperature,the concentration of the adsorbed dye,and the p H value of the dye solution were investigated.It was found that when the adsorption temperature was 303 K,the concentration of the dye solution was 100 ppm,and the p H of the adsorption solution was 9,the porous carbon material exhibited the fastest adsorption rate of methylene blue dye.And the adsorption kinetics of decolorization isotherm was found,that the pseudo-first-order kinetics equation could fit the adsorption process well. |
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