In this research, a novel green tillite-based adsorbent (CMT) was synthesized by modifying the surface of natural/pristine tillite (PT) with Chrysophyllum albidum stem bark extract for the efficient removal of Cr(VI) from water. The physicochemical characteristics of PT and CMT were assessed by the use of the FTIR, XRD, BET, TGA, and SEM techniques. Cardinal adsorptive parameters such as solution pH, contact time, adsorbent dose, and initial concentration were used to optimize the efficiency of PT and CMT for Cr(VI) adsorption. The Elovich kinetic model was noticed to best describe the uptake of Cr(VI) onto PT and CMT. Hence, chemisorption was the rate-controlling step for Cr(VI) uptake onto both PT and CMT. Meanwhile, the Langmuir maximum adsorption capacity of PT and CMT was 51.06 and 291.8 mg g⁻¹ respectively, which was higher than those obtained for most materials used for Cr(VI) uptake. The Langmuir and Freundlich models best describe the equilibrium adsorption data for PT and CMT respectively. The reusability assessment of PT and CMT showed over 90% of the initial Cr(VI) uptake even after the fifth cycle of reuse. Electrostatic interaction and reduction of Cr(VI) were responsible for the removal of Cr(VI) from water onto the green material. The uptake of Cr(VI) was thermodynamically feasible, entropy-driven, and endothermic on both PT and CMT. The outcome of this study revealed that the anchoring of Chrysophyllum albidum stem bark extract on tillite produced a green adsorbent, which was highly efficient for the removal of Cr(VI) from polluted water.

在这项研究中，一种新颖的基于冰碛岩绿色吸附剂（CMT）通过修饰天然/原始冰碛岩（PT）的与所述表面的合成金叶树属albidum干树皮提取物用于从水中有效去除铬（VI）的。PT和CMT的理化特性通过FTIR，XRD，BET，TGA和SEM技术进行评估。主要吸附参数（例如溶液的pH值，接触时间，吸附剂剂量和初始浓度）用于优化PT和CMT吸附Cr（VI）的效率。注意到Elovich动力学模型最能描述PT和CMT对Cr（VI）的吸收。因此，化学吸附是PT和CMT吸收Cr（VI）的速率控制步骤。同时，Langmuir PT和CMT的最大吸附容量为51.06和291.8 mg g^-1分别比大多数用于Cr（VI）吸收的材料获得的^-1高。Langmuir和Freundlich模型分别最好地描述了PT和CMT的平衡吸附数据。PT和CMT的可重复使用性评估表明，即使在第五个重复使用周期之后，初始Cr（VI）吸收量也超过了90％。静电相互作用和Cr（VI）的还原是将Cr（VI）从水中去除到绿色材料上的原因。在PT和CMT上，Cr（VI）的吸收在热力学上是可行的，是熵驱动的，并且是吸热的。本研究的结果揭示，锚定金叶树属albidum干树皮提取物上冰碛岩生产的生吸附剂，这是高效率的用于从污染的水中除去的Cr（VI）。