KOH活化法制备棉秆基活性炭及其对含苯酚废水的吸附

以农业废弃物棉秆为原料，采用氢氧化钾活化法制备活性炭，并用于吸附含苯酚废水中的苯酚。棉秆基活性炭的最佳制备条件为棉秆先炭化，以KOH溶液为活化剂，KOH与棉秆炭的质量比(物料比)1.5:1，活化温度800 ℃、活化时间70 min，此条件下制备的棉秆活性炭亚甲基蓝的吸附值为342.33 mg/g，碘吸附值为1 368.65 mg/g，其BET比表面积达到了1 735.94 m²/g，总孔容积0.36 cm³/g，平均孔径2.33 nm。将此活性炭用于吸附苯酚，苯酚质量浓度60 mg/L的50 mL废水中，当pH值为7,吸附时间2 h，活性炭投放量为50 mg时，苯酚去除率最高可达98%。对此吸附过程进行动力学分析，结果表明准二级动力学模型能很好的描述此活性炭吸附苯酚的过程。

Preparation of Cotton Stalk Based Activated Carbon by KOH Activation and Its Adsorption Capacity for Phenol Wastewater

The activated carbon, which was obtained with agricultural waste cotton stalk as raw material, was prepared by the activation of potassium hydroxide and used to adsorb phenol wastewater. The optimum preparation conditions for cotton stalk based activated carbon were carbonized cotton stalk, KOH as activator, mass ratio of KOH and carbonized cotton stalk (material ratio) 1.5:1, activation temperature 800 ℃, activation time 70 min. Under these conditions, the adsorption value of methylene blue was 342.33 mg/g, and the iodine adsorption value was 1 368.65 mg/g. The BET specific surface area was 1 735.94 m²/g, the total pore volume was 0.36 cm³/g, and the average pore size was 2.33 nm. The activated carbon was used to adsorb phenol wastewater. When the amount of activated carbon was 50 mg, the mass concentration of phenol was 60 mg/L, the volume of wasterwater was 50 mL, the pH value was 7 and the adsorption time was 2 h, the removal rate of phenol was up to 98%. The kinetic analysis of the adsorption process showed that the pseudo-second-order kinetic model could better describe the process of the activated carbon adsorption of phenol.