Abstract The objective of this study is to model the breakthrough adsorption curves of Co (II) ions using spent tealeaves in fixed-bed column experiments. Spent leaves of green tea (GT), peppermint tea (PM) and chamomile (CM) were packed in glass columns with a diameter of 2 cm and height of 15 cm, and used as filters for the removal of the pollutant. Aqueous solutions of Cobalt (II) ions (100 mg/L) at pH 6 were prepared and pumped against gravity through the columns at a uniform flow rate of 5 mL/min. Breakthrough curves were fitted for the residual concentration data using the Thomas, Yoon-Nelson, and Clark models, with added empirical terms to delineate the lower tail of the breakthrough curve. These mathematical models were successfully linearized using the natural logarithm for parameter estimation. The results reveal that the Co (II) adsorption fits all three models for all the adsorbents. The Thomas model indicated that the calculated adsorption capacities followed the trend: PM > GT > CM with values of 59.7, 25.2, and 24.9 mg/g respectively. Moreover, CM showed the highest adsorption rates with all the mathematical models, whereas Yoon-Nelson theory provided evidence that PM has the longest 50% adsorption breakthrough among the adsorbents. Lastly, morphological and textural studies indicate that all spent leaves are good candidates as adsorbents due to their high surface heterogeneity. This study proposes the use of spent tealeaves as Co (II) adsorbents because they are inexpensive and environmentally beneficial.

中文翻译：

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固定床柱吸附废茶叶上钴 (II) 离子突破曲线的模拟

摘要本研究的目的是在固定床柱实验中使用废茶叶模拟 Co (II) 离子的突破吸附曲线。将绿茶(GT)、薄荷茶(PM)和洋甘菊(CM)的废叶装入直径2厘米、高15厘米的玻璃柱中，用作过滤器去除污染物。制备 pH 6 的钴 (II) 离子 (100 mg/L) 水溶液，并以 5 mL/min 的均匀流速克服重力泵入色谱柱。使用 Thomas、Yoon-Nelson 和 Clark 模型对残留浓度数据拟合突破曲线，并添加经验项来描绘突破曲线的下尾部。使用自然对数进行参数估计，成功地将这些数学模型线性化。结果表明，Co (II) 吸附适合所有吸附剂的所有三个模型。Thomas模型表明，计算的吸附容量遵循以下趋势：PM>0。GT> CM 值分别为 59.7、25.2 和 24.9 mg/g。此外，CM 在所有数学模型中均表现出最高的吸附率，而 Yoon-Nelson 理论提供的证据表明 PM 在吸附剂中具有最长的 50% 吸附突破。最后，形态和结构研究表明，所有废叶由于其表面异质性高，都是作为吸附剂的良好候选者。这项研究建议使用废茶叶作为 Co (II) 吸附剂，因为它们价格低廉且对环境有益。