Enhanced Adsorption of Orange II Using Cationic Surfactant Modified Biochar Pyrolyzed from Cornstalk
Enhanced Adsorption of Orange II Using Cationic Surfactant Modified Biochar Pyrolyzed from Cornstalk
复制标题
使用阳离子表面活性剂改性玉米秆热解生物炭增强橙 II 的吸附
DOI：
10.1155/2016/8457030
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发表时间：
2016-01-01
影响因子：
3
通讯作者：
Liu, Lili
中科院分区：
文献类型：
--
作者：
Mi, Xiao;Li, Guoting;Liu, Lili
由于生物质原料用作吸附剂时溶解严重，从生物质热解得到的廉价生物质炭可能是一种很好的基质。采用十六烷基三甲基溴化铵(CTAB)对玉米秸秆生物质炭进行改性，制备出可去除带负电荷污染物的复合吸附剂。改性后，阴离子染料橙II(ORII)的脱色率从原始玉米秸秆生物炭的46.9%提高到CTAB改性玉米秸秆生物炭的99.7%。酸性条件下对ORI的吸收有利，碱性条件下对ORI的吸收不利。通过非线性模拟，Elovich模型能较好地描述吸附动力学。对于动力学数据的线性模拟，拟二级动力学模型对实验点的拟合度要好于拟一级动力学模型。动力学分析表明，十六烷基三甲基溴化铵修饰的玉米秸秆生物炭对ORII的吸附过程可能是化学吸附伴随着离子交换。298K时，改性生物炭的最大吸附容量为26.9 mg/g，符合Langmuir模型。随着反应温度的升高，ORiI的吸附量增加。计算出吸附过程的热焓为38.45KJ·−-1，吸附过程的熵为185.0 J·−·1K·−-1。在288K、298K和308K时的负值分别为−14.92、−16.50和−18.62KJ·−~(-1)。上述热力学分析表明，该吸附过程是吸热自发的。
As dissolution of raw biomass is serious when used as an adsorbent, the cheap biochar pyrolyzed from biomass might be a good matrix. Raw cornstalk biochar was intentionally modified by cetyltrimethylammonium bromide (CTAB) to prepare the composite adsorbent designed for the removal of negatively charged pollutants. After modification, the removal efficiency for anionic dye Orange II (ORII) increased from 46.9% of the virgin cornstalk biochar to 99.7% of the CTAB-modified cornstalk biochar. The uptake of ORII proved to be favorable under acidic conditions but unfavorable under alkaline conditions. By nonlinear simulation, the Elovich model was the best to describe the adsorption kinetics. For linear simulation of the kinetic data, the pseudo-second-order kinetic model fitted the experimental points better than the pseudo-first-order model. Kinetic analysis indicated that the ORII adsorption process on the CTAB-modified cornstalk biochar might be chemical adsorption accompanied by ion exchange. At 298 K, the maximal adsorption capacity of the modified biochar is 26.9 mg/g by the Langmuir model. The adsorption of ORII increased with a rise in the reaction temperature. The enthalpy and entropy of the adsorption process are calculated to be 38.45 KJ mol−1 and 185.0 J mol−1 K−1, respectively. The negative values of at 288, 298, and 308 K were −14.92, −16.50, and −18.62 KJ mol−1, respectively. The above thermodynamic analysis demonstrates that the adsorption process was endothermic and spontaneous.