添加小麦秸秆生物炭对黄土吸附苯甲腈的影响
发布时间：2019-05-22 20:53
【摘要】：选择苯甲腈为目标污染物,研究添加不同热解温度制备小麦秸秆生物碳对黄土吸附苯甲腈的影响.研究表明:不加生物炭黄土对苯甲腈的吸附约8h达到平衡,而加入生物炭后,黄土对苯甲腈的吸附时间缩短,并随着加入生物炭热解温度的升高,吸附平衡时间缩短越明显,同时,黄土对苯甲腈的饱和吸附量也显著增加;添加生物炭黄土对苯甲腈的动力学吸附数据显示较好的符合了准二级动力学方程;无论是否添加生物炭,苯甲腈在黄土上的吸附都符合Freundlich吸附的等温模型,随系统温度升高,添加生物炭黄土对苯甲腈的饱和吸附量也显著增加,表明该吸附过程为吸热反应;苯甲腈在黄土上的吸附等温线符合C-型吸附等温模式.计算结果显示,平均吸附自由能E介于1.865~3.171k J/mol,表明苯甲腈在黄土上的吸附,无论是否添加生物炭,都以物理吸附为主;热力学参数计算结果显示,无论是否添加生物炭,黄土对苯甲腈的吸附过程中吉布斯自由能ΔGθ均小于0、熵变ΔS~θ和焓变ΔH~θ均大于0,表明土壤对苯甲腈的吸附为自发进行的吸热过程.研究结果说明,添加生物炭黄土对苯甲腈的吸附过程包含表面吸附和颗粒内部扩散、外部液膜扩散等机制.
[Abstract]:The effect of wheat straw biocarbon prepared by adding different pyrolysis temperature on the adsorption of benzonitrile by loess was studied by using benzonitrile as the target pollutant. The results show that the adsorption time of benzonitrile is shortened after adding biochar, and the adsorption equilibrium time is shortened with the increase of pyrolysis temperature. At the same time, the saturated adsorption capacity of benzonitrile in loess also increased significantly. The kinetic adsorption data of benzonitrile by adding biocarbon loess showed that it was in good agreement with the quasi-second-order kinetic equation. No matter whether biological carbon is added or not, the adsorption of benzonitrile on loess accords with the isotherm model of Freundlich adsorption. With the increase of system temperature, the saturated adsorption capacity of benzonitrile on loess added with biochar also increases significantly, indicating that the adsorption process is endothermic. The adsorption isotherms of benzonitrile on loess are in accordance with the C-type adsorption isotherm model. The results show that the average adsorption free energy E is 1.865 鈮，
本文编号：2483254
[Abstract]:The effect of wheat straw biocarbon prepared by adding different pyrolysis temperature on the adsorption of benzonitrile by loess was studied by using benzonitrile as the target pollutant. The results show that the adsorption time of benzonitrile is shortened after adding biochar, and the adsorption equilibrium time is shortened with the increase of pyrolysis temperature. At the same time, the saturated adsorption capacity of benzonitrile in loess also increased significantly. The kinetic adsorption data of benzonitrile by adding biocarbon loess showed that it was in good agreement with the quasi-second-order kinetic equation. No matter whether biological carbon is added or not, the adsorption of benzonitrile on loess accords with the isotherm model of Freundlich adsorption. With the increase of system temperature, the saturated adsorption capacity of benzonitrile on loess added with biochar also increases significantly, indicating that the adsorption process is endothermic. The adsorption isotherms of benzonitrile on loess are in accordance with the C-type adsorption isotherm model. The results show that the average adsorption free energy E is 1.865 鈮，
本文编号：2483254
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