稻壳基活性炭的焦磷酸活化制备及其吸附特性

Preparation of pyrophosphoric acid activated carbon based on rice hull and its adsorption properties

以焦磷酸为活化剂制备稻壳基活性炭,并考察了其吸附特性。结果表明,制备稻壳基活性炭的最佳工艺条件为:浸渍时间3h,剂料比0.6,活化温度450℃,活化时间90min。在此条件下,稻壳基活性炭的亚甲基蓝吸附值为235.4mg/g。苯酚在稻壳基活性炭上的吸附过程符合Freundlich吸附等温线和拟二级动力学模型。热力学分析表明,该吸附过程为自发进行的多层吸附,且以化学吸附为主。

The activated carbon from rice husk with pyrophosphoric acid as activator was prepared and its adsorption proper- ties were investigated. The results showed that the optimum conditions for preparing rice hull based activated carbon were as follows：the impregnation time was 3 h, the material ratio was 0.6, the activation temperature was 450℃ ,and the activation time was 90 min. Under this condition, the methylene blue adsorption value of activated carbon from rice husk 235.4 mg/g. The adsorption process of phenol on rice hull based activated carbon was in accordance with the Freundlich adsorption isotherm and the quasi two order kinetic model. The thermo-dynamic analysis showed that the adsorption process was a spontaneous multi- layer adsorption and mainly chemical adsorption.