Qian Qingrong, Machida Motoi, Tatsumoto Hideki
Graduate School of Science and Technology, Chiba University, Yayoi-cho 1-33 Inage-ku, Chiba 263-8522, Japan.
Waste Manag. 2008;28(6):1064-71. doi: 10.1016/j.wasman.2007.03.029. Epub 2007 Jun 5.
Two activated carbons (ACs) prepared from cattle manure compost (CMC) by ZnCl(2) activation were selected and out-gassed in a helium flow at various temperatures for 2h. The pore structure and surface chemical properties of the two selected ACs and their out-gassing treated ACs were characterized using N(2) adsorption-desorption, elements analysis, SEM and Boehm titration. A basic dye, methylene blue (MB), was chosen as an adsorbate to investigate the adsorption capacity for organic contaminant onto the activated carbons. It was found that the out-gassing treatment at 400 degrees C had little effect on the textural characteristics of the carbons but significantly changed the surface chemical properties such as surface functional groups concentration, pH and pH(PZC). The CMC-based activated carbons exhibited excellent performance for MB adsorption due to their high surface area, large mesopore volume and high nitrogen content. The kinetics of MB adsorption onto the activated carbons followed a pseudo-second-order equation, and the equilibrium data agreed well with the Langmuir model under the experimental conditions. The highest adsorption rate constant of k(ad) and the largest adsorption capacity of q(m) were found be 1.44x10(-4)g/mgmin and 519mg/g, respectively. The results suggested that the CMC-based activated carbons were effective adsorbents for the removal of methylene blue from aqueous solution.
选取了通过ZnCl₂活化由牛粪堆肥(CMC)制备的两种活性炭(AC),并在氦气流中于不同温度下脱气2小时。使用N₂吸附 - 解吸、元素分析、扫描电子显微镜(SEM)和 Boehm滴定法对两种选定的AC及其脱气处理后的AC的孔结构和表面化学性质进行了表征。选择碱性染料亚甲基蓝(MB)作为吸附质,研究活性炭对有机污染物的吸附能力。结果发现,400℃的脱气处理对活性炭的结构特征影响不大,但显著改变了表面化学性质,如表面官能团浓度、pH值和零电荷点(PZC)。基于CMC的活性炭由于其高比表面积、大的中孔体积和高氮含量,对MB吸附表现出优异的性能。MB在活性炭上的吸附动力学遵循准二级方程,在实验条件下平衡数据与Langmuir模型吻合良好。发现最高吸附速率常数k(ad)和最大吸附容量q(m)分别为1.44×10⁻⁴g/mg·min和519mg/g。结果表明,基于CMC的活性炭是从水溶液中去除亚甲基蓝的有效吸附剂。