Al-Balqa Applied University, Al-Huson University College, Department of Chemical Engineering, Jordan.
Department of Water and Environmental Engineering, German Jordanian University, Jordan.
Sci Total Environ. 2021 Mar 20;761:143229. doi: 10.1016/j.scitotenv.2020.143229. Epub 2020 Oct 24.
Industrial processes generate toxic organic molecules that pollute environment water. Phenol and its derivative are classified among the major pollutant compounds found in water. They are naturally found in some industrial wastewater effluents. The removal of phenol compounds is therefore essential because they are responsible for severe organ damage if they exist above certain limits. In this study, ground Ziziphus leaves were utilized as adsorbents for phenolic compounds from synthetic wastewater samples. Several experiments were performed to study the effect of several conditions on the capacity of the Ziziphus leaves adsorbent, namely: the initial phenol concentration, the adsorbent concentration, temperature, pH value, and the presence of foreign salts (NaCl and KCl). The experimental results indicated that the adsorption process reached equilibrium in about 4 h. A drop in the amount of phenol removal, especially at higher initial concentration, was noticed upon increasing the temperature from 25 to 45 °C. This reflects the exothermic nature of the adsorption process. This was also confirmed by the calculated negative enthalpy of adsorption (-64.8 kJ/mol). A pH of 6 was found to be the optimum value at which the highest phenol removal occurred with around 15 mg/g at 25 °C for an initial concentration of 200 ppm. The presence of foreign salts has negatively affected the phenol adsorption process. The fitting of the experimental data, using different adsorption isotherms, indicated that the Harkins-Jura isotherm model was the best fit, evident by the high square of the correlation coefficient (R) values greater than 0.96. The kinetic study revealed that the adsorption was represented by a pseudo-second-order reaction. The results of this study offer a basis to use Ziziphus leaves as promising adsorbents for efficient phenol removal from wastewater.
工业过程会产生有毒的有机分子，污染环境水。苯酚及其衍生物被归类为水中主要的污染物化合物之一。它们天然存在于一些工业废水废水中。因此，去除苯酚化合物是必要的，因为如果它们存在于一定的限度以上，就会对器官造成严重的损害。在这项研究中，枣叶被用作从合成废水样品中吸附酚类化合物的吸附剂。进行了多项实验来研究几种条件对枣叶吸附剂的吸附能力的影响，这些条件包括：初始苯酚浓度、吸附剂浓度、温度、pH 值和外来盐（NaCl 和 KCl）的存在。实验结果表明，吸附过程在大约 4 小时内达到平衡。当温度从 25°C 升高到 45°C 时，发现苯酚去除量下降，特别是在初始浓度较高时，这表明吸附过程是放热的。这也被计算得到的负吸附焓（-64.8 kJ/mol）所证实。发现 pH 值为 6 时是最佳值，在 25°C 时，初始浓度为 200ppm 时，苯酚去除率最高，约为 15mg/g。外来盐的存在对苯酚的吸附过程产生了负面影响。使用不同的吸附等温线对实验数据进行拟合表明，Harkins-Jura 等温线模型是最佳拟合，这一点可以从相关系数（R）值大于 0.96 的高平方得到证明。动力学研究表明，吸附由伪二级反应表示。这项研究的结果为使用枣叶作为从废水中有效去除苯酚的有前途的吸附剂提供了依据。
