磷酸化学一步炭活化菌糠制备高吸附性能粉末活性炭

Preparation of powdered activated carbon from wasted mushroom substrate by phosphoric acid activation

以菌糠为原料,在机械力化学技术前处理条件下,采用磷酸化学一步炭活化法制备高吸附性能的粉末活性炭.通过单因素试验探讨了不同制备条件对活性炭得率及其吸附性能的影响,并选取浸渍比、球磨时间、活化温度和活化时间4种因素,采用L9(34)正交设计试验,初步筛选较优性能的活性炭制备工艺.采用比表面及孔径分析仪、扫描电镜表征活性炭的孔结构和形貌特征.结果表明:当预处理球磨时间为30 min,浸渍比为2.0,活化温度为450℃,活化时间为60 min时,得到的活性炭的碘吸附值为962.94 mg·g-1,亚甲基蓝吸附值为150.0 mg·g-1,焦糖脱色率为144.63%,得率为36.20%.

Wasted mushroom substrate is considered as an excellent ingredient for activated carbon due to its properties of rich organic matter contents, loose texture and high adsorption to chemicals. A mechanochemical process, consisting of pre-grinding and phosphoric acid activation, was proposed to manufacture activated carbon from wasted mushroom substrates. Effects of different factors, including the impregnation ratio of phosphoric acid and substrate, grinding time, activation temperature and time, on the yields and adsorption properties of activated carbon were investigated via single factor experiment. And a L9(34) orthogonal design was used to determine the optimal processing conditions. Textural characteristics and morphology were further characterized by N2 adsorption analysis and scanning electron microscope. The results showed that the optimal procedure was to grind the ingredients under ball mill for 30 min before being impregnated and activated in pure phosphoric acid at the ratio of 2.0 under 450 ℃ for 60 min. The yield of activated carbon reached 36.20%, with iodine number, methylene blue adsorption rate, and caramel removal efficiency being 962.94 and 150 mg·g-1, and 144.63%, respectively.