AbstractActivated carbon (BC) prepared from olive oil solid waste (olive husk) by slow pyrolysis was chemically activated using MgCl2 (BC-MgCl2). The BC and BC-MgCl2 were used as adsorbents for removal of three phenolic compounds, namely, phenol (P), p-methoxyphenol (PMP) and p-nitrophenol (PNP), from aqueous solution. The uptake of these three phenolic compounds by the BC and BC-MgCl2 was better expressed by the Langmuir and Dubinin–Radushkevich (D-R) isotherm models than by the Freundlich isotherm, and the kinetics of the adsorption process followed the pseudo-second order kinetic model. The maximum monolayer adsorption capacity of P, PMP and PNP were increased from 24.938, 45.455 and 61.728 on BC to 43.860, 98.039 and 121.951 mg/g on BC-MgCl2 by factors of 1.76, 2.16 and 1.98, respectively. Therefore, the chemical activation of BC by MgCl2 is indeed of importance for improving its adsorption performances. For both adsorbents, the adsorption phenomenon for different substituted phenols is a strong function of solubility, polarity, molecule structure, and size. At the tested temperatures (25, 35 and 45 °C), the negative values of ΔG° and positive values of ΔH° and ΔS° for the adsorption of P, PMP and PNP on BC and BC-MgCl2 demonstrated that the adsorption was a spontaneous, endothermic and entropy-increasing process.

中文翻译：

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使用源自橄榄壳的 MgCl2 浸渍活性炭去除水溶液中的酚类化合物：化学结构的影响

摘要由橄榄油固体废物（橄榄壳）通过缓慢热解制备的活性炭（BC）使用MgCl2（BC-MgCl2）进行化学活化。BC和BC-MgCl2用作吸附剂，用于去除水溶液中的三种酚类化合物，即苯酚(P)、对甲氧基苯酚(PMP)和对硝基苯酚(PNP)。Langmuir 和 Dubinin-Radushkevich (DR) 等温线模型比 Freundlich 等温线模型更好地表达了 BC 和 BC-MgCl2 对这三种酚类化合物的吸附，吸附过程的动力学遵循准二级动力学模型。P、PMP和PNP的最大单层吸附容量从BC上的24.938、45.455和61.728增加到BC-MgCl2上的43.860、98.039和121.951mg/g，分别增加了1.76、2.16和1.98倍。因此，MgCl2对BC的化学活化对于提高其吸附性能确实具有重要意义。对于这两种吸附剂，不同取代酚的吸附现象是溶解度、极性、分子结构和尺寸的强函数。在测试温度（25、35和45℃）下，BC和BC-MgCl2对P、PMP和PNP的吸附ΔG°为负值，ΔH°和ΔS°为正值，表明吸附是自发的、吸热的和熵增加的过程。