Study On Adsorption Of Methylene Blue From Aqueous Solution By Activated Carbon Materials

Dye wastewater has become one of the main sources of natural water pollution in China.Among them,methylene blue dye is low in toxicity and poor in biodegradability and difficult to be degraded,and it is difficult to remove conventional water treatment methods.Therefore,seeking an efficient,practical and environmentally friendly water treatment method is of great significance for water environment treatment.In this paper,three activated carbons W-200,830 and F20 are used to remove methylene blue dye,and the equilibrium adsorption time is determined to be 12 hours.Compared with the adsorption performance of the three activated carbons,the activated carbon W-200 with the best adsorption performance is selected,and then passed through the power,The effect of each factor on the adsorption of methylene blue dye wastewater by activated carbon W-200 was investigated by using the study of isothermal and isotherm.Finally,the response surface method was used to analyze and analyze the actual simulated methylene blue dye wastewater adsorption by activated carbon W-200,and the optimal operating conditions for adsorption were obtained.The results of kinetic studies show that the adsorption conforms to a pseudosecond-order kinetic model.As the initial dye concentration increases from 20 mg/g to70 mg/g,the initial adsorption rate of activated carbon W-200 increases from 1498.36mg/(g?h).To27986.09 mg/(g?h),the highest equilibrium adsorption capacity is 832.99mg/g;when the solution temperature is different,the equilibrium adsorption capacity is reduced from 666.67 mg/g at 15℃ to 555.56 mg/g at 45℃.In the first 2 hours,the higher the temperature,the faster the initial adsorption rate,but the final equilibrium adsorption amount decreases with increasing temperature.Combined with Arrhenius formula,it proves that the adsorption reaction belongs to physical adsorption.The equilibrium adsorption capacity of activated carbon increased rapidly due to the negative charge on the surface of activated carbon and the electrostatic adsorption of cationic dyes;the increase of the chloride ion concentration increased the initial adsorption rate of activated carbon,and the initial adsorption rate was 1724.47 mg when the chloride ion concentration was 1 m M/(g?h),when the concentration is 100 m M,the initial adsorption rate is 2892.52 mg/(g?h),which is caused by the salting out effect.The results of the isotherm study show that the adsorption of methylene blue by activated carbon W-200 conforms to the Langmuir model,the temperature increases from 15℃to 45℃,and the saturated adsorption capacity of activated carbon decreases from 662.25 mg/g to 606.06 mg/g.It can be concluded that the adsorption is a spontaneous exothermic reaction;the p H of the solution is between 3-9 and conforms to the Langmuir model.When p H=11,the model no longer meets the model and is caused by electrostatic adsorption.The chloride ion concentration of the solution increased from 1 m M to 100 m M,The saturated adsorption capacity increased from636.943 mg/g to 740.741 mg/g,and the salt adsorption effect increased the saturated adsorption capacity.The adsorption experiments simulating the actual dye wastewater show that the established response surface model has obvious significance.The contours and response surfaces are used to comprehensively analyze the interaction between various factors,and the optimal operating conditions of the adsorption reaction are obtained.The initial concentration of methylene blue dye was 69.94 mg/L,the solution temperature was 22.62℃,the solution p H=10.75,and the chloride ion concentration in the solution was 97.59 m M.The activated carbon W-200 reached the optimal adsorption capacity.