Batch adsorption experiments have been conducted to investigate the removal of methyl orange from aqueous solution by an activated carbon prepared from prickly pear seed cake by phosphoric acid activation. The adsorption process has been described by using kinetic and isotherm models. The kinetic of adsorption was examined by pseudo-first-order, pseudo-second-order, and intraparticle diffusion models. Adsorption isotherm was modeled using Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherms. The adsorption process of methyl orange was well explained by the pseudo-second-order model and Freundlich isotherm. Also, pseudo-n-order model has been applied to estimate the order of adsorption kinetic and it was found equal to 2 which confirm the good accuracy of the pseudo-second order. Moreover, Dubinin–Radushkevich isotherm reveals that the adsorption of methyl orange onto activated carbon was a physisorption process in nature. The adsorption capacity of activated carbon was found to be 336.12 mg/g at temperature 20°C and . These results demonstrated that the prickly pear seed cake is a suitable precursor for the preparation of appropriate activated carbon for dyes removal from aqueous solution.

中文翻译：

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用于染料去除的活性炭：吸附过程的建模和理解

已经进行了批量吸附实验，以研究通过磷酸活化从仙人掌籽饼制备的活性炭从水溶液中去除甲基橙。吸附过程已通过使用动力学和等温线模型进行描述。吸附动力学通过拟一级、拟二级和颗粒内扩散模型进行检验。吸附等温线使用 Langmuir、Freundlich、Temkin 和 Dubinin-Radushkevich 等温线建模。拟二级模型和Freundlich等温线很好地解释了甲基橙的吸附过程。此外，伪n阶模型已被应用于估计吸附动力学的阶数，发现等于2，这证实了伪二阶模型的良好准确性。而且，Dubinin-Radushkevich 等温线表明，甲基橙在活性炭上的吸附本质上是一个物理吸附过程。发现活性炭的吸附容量在 20°C 和 336.12 毫克/克。这些结果表明，仙人掌籽饼是制备用于从水溶液中去除染料的合适活性炭的合适前体。