Preparation of Activated Carbon from Soybean Straw for High-efficiency Adsorption Methylene Blue in Aqueous Solution

摘要

With the wide application of dyes in various fields, the environmental and health problems caused by dye pollution gradually attracted the attention of researchers. It is particularly important to find a kind of activated carbon with high adsorption performance and low cost. The activated carbon (SSAC) was prepared by KOH activating soybean straw (SS). The resultant SSAC exhibited a super high specific surface area of 1906.87 m~2/g, abundant micropo-res volume of 0.541 cm~3/g, and mesopores volume of 0.625 cm~3/g, respectively. The analysis results of FT-IR and XPS show that the main mechanism is that the C-0 and O-C=O groups on the surface of SSAC are connected with the N atoms in methylene blue (MB) molecule through a hydrogen bond, accompanied by physical adsorption. The maximum theoretical adsorption capacity of 2080.50 mg/g was obtained by the Langmuir model fitted batch adsorption experimental data. The fixed bed experiment showed that the adsorption capacity was 965.72 mg/g. After three batch and fixed bed adsorption/desorption cycles, the regeneration adsorption efficiency was 85.17 % and 81.33 %, respectively.