麻秆基介孔活性炭的制备及对甲基橙的吸附

Preparation of hemp stem-based mesoporous activated carbon and its adsorption for methyl orange

以农业固体废物大麻麻秆为原料,采用环境友好的水蒸气活化法制备孔径可控的介孔活性炭,将其作为吸附剂去除模拟废水中的染料甲基橙(MO),考察MO的初始浓度、温度、吸附时间和pH值对吸附性能的影响。结果表明,在800℃制备的麻秆基介孔活性炭HMAC800,其比表面积可达1 436.5 m^(2)/g,具有丰富且均一的介孔(~3 nm),介孔容积高达1.71 cm^(3)/g,其表面有丰富的含氧官能团,有助于对大分子染料MO的吸附;在25℃,MO初始浓度为100 mg/L,HMAC800用量为10 mg, pH为7,吸附时间为120 min的最佳吸附条件下平衡吸附量可达487 mg/g,去除率接近100%,HMAC800对MO的吸附过程符合准二级动力学模型;HMAC800的最大吸附量高达769.2 mg/g,吸附等温线符合Langmuir模型。

The pore size controllable mesoporous activated carbon was prepared by an environmentally friendly water vapor activation method using agricultural solid waste hemp stem as raw material, and it was used as an adsorbent to remove the dye methyl orange(MO) from simulated wastewater.The effects of activation temperature, initial concentration of MO,initial pH value and reaction time on the structure and the adsorption of the hemp stem-based mesoporous activated carbon were investigated.The results showed that the hemp stem-based mesoporous activated carbon HMAC800 prepared at 800 ℃ had a specific surface area of 1 436.5 m^(2)/g, rich and homogeneous mesopores(~3 nm) and a mesopore volume of 1.71 cm^(3)/g, and its surface was rich in oxygen-containing functional groups, which was helpful for the adsorption of the large molecule dye MO;The equilibrium adsorption capacity could reach 487 mg/g under the optimal adsorption conditions of 25 ℃,initial concentration of 100 mg/L of MO,HMAC800 dosage of 10 mg, pH 7,adsorption time of 120 min, and the removal efficiency was close to 100%,and the adsorption process of HMAC800 on MO was in accordance with the pseudo-second-order model;the maximum adsorption capacity of HMAC800 was up to 769.2 mg/g, and the adsorption isotherm was in accordance with the Langmuir model.