Adsorption Performance for Methylene Blue on Biochar Derived from Peanut Shell and Corn Cob

Peanut shell and corn cob were used as the raw materials to prepare the biochar under the temperature of700℃ and 450℃ ． The effects of various parameters such as initial concentration of methylene blue,biochar dosage,temperature,and pH value on the adsorption of methylene blue were investigated. The characteristics of adsorption kinetics and isotherms of methylene blue on biochar were analyzed. The results showed that increasing dose of biochar caused lower adsorption capacity and higher removal rate of methylene blue. The adsorption capacity of methylene blue on biochar increased with a rise in initial concentration of methylene blue,temperature and pH value. The kinetic data showed that it was fitted well with the pseudo-second order model（ R²= 0. 992 ～ 0. 999）,suggesting adsorption process was influenced by chemical adsorption. The adsorption data of biochar were well fitted with Langmuir model（ R²= 0. 992 ～ 0. 995）. The theoretical maximum adsorption capacity of methylene blue on PSB700、PSB450,CCB700,CCB450 were 10. 247 mg/g,6. 449 mg/g,7. 919 mg/g,2. 860 mg/g,indicating the adsorption capacity was in the order of PSB700 > CCB700 > PSB450 > CCB450.