Study on Preparation of Activated Carbon from Soybean Straw and Its Adsorption Performance on Cu²⁺

The activated carbon was prepared from soybean straw by using ZnCl₂ as the activation agent and analysis methods such as SEM and FT-IR were used to characterize the SSAC. The influence of activation time and activation temperature on methylene blue adsorption value for soybean straw activated carbon were studied,and the adsorption characteristics of Cu²⁺ using the SSAC in water solution were studied through static experiments,the influence of solution pH value,temperature and time were investigated. The results showed that the optimum preparation conditions were determined as follows: The activation concentration of ZnCl₂was 3 mol/L,carbonization temperature was 700 ℃,carbonization time was 40 min. Under this condition,the methylene blue adsorption value for SSAC was 1.84 mL/0.1 g. When the initial concentration of Cu²⁺ was 10 mg/L,the dosage of SSAC was 0.2 g,SSAC had the best adsorption effect when pH was 5.0,temperature was 50 ℃ and time was 50 min. The maximum adsorption capacity of SSAC was 4.589 mg/g,the removal rate was 91.77%. The morphology and structure of active carbon were observed by SEM and FT-IR,the activated carbon had rich and developed fracture structure based on multi-layer graphite,which was rich in oxygen-containing functional groups such as hydroxyl carboxyl ketonic carbonyl aliphatic ether and ester group on the surface. Therefore,this activated carbon has a good adsorption performance for Cu²⁺ ions,it is suitable for treating wastewater containing Cu²⁺ and metal ion adsorption.