The simultaneous removal of Cadmium ions and reactive yellow 4 dye (RY4 dye) by bone meal-derived apatite (BMDA) were investigated in a batch process. The structural elucidation of the prepared BMDA was done using TEM, XRD, FT-IR and EDX to evaluate the structures of the adsorbent. Different experimental features such as the agitation time, BMDA dosage, temperature, initial adsorbate concentration and pH of the solution were examined on the uptake pattern of the pollutants. The mechanism of adsorption was examined with Elovich, pseudo-first-order, intraparticle diffusion and pseudo-second-order kinetic models, while Langmuir, Dubinin-Radushkevich (D-R), Freundlich and Tempkin isotherms were exploited in order to describe the behaviour of the equilibrium process. Analysis from XRD revealed peaks corresponding to single phase apatite powder, while the various forces responsible for the interactions between the BMDA surface and the pollutants were obtained to CO 3 2− , OH − and PO 4 3− as observed by FT-IR analysis. SEM and TEM investigations confirmed a round-like morphology which agglomerated together upon the adsorption of pollutants. The kinetic modelling of the adsorption data were well illustrated with the pseudo-first-order model with correlation coefficient ( R 2 ) values ranging from 0.997 to 0.999. Isotherms studies revealed that best fit was achieved with Langmuir isotherm with adsorption capacities of 94.85 and 116.16 mg/g for RY4 dye and Cd(II) ions respectively. Thermodynamic study signified the uptake of the pollutants to be spontaneous, feasible and endothermic in nature. The values of entropy change (Δ S ) for the sorption processes calculated are 86.57 and 60.16 J/mol/K for Cd(II) and RY4 dye, respectively.

中文翻译：

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骨粉衍生的磷灰石同时去除水溶液中的镉 (II) 离子和活性黄 4 染料：动力学、平衡和热力学评估

在批处理中研究了通过骨粉衍生的磷灰石 (BMDA) 同时去除镉离子和活性黄 4 染料（RY4 染料）。使用 TEM、XRD、FT-IR 和 EDX 对制备的 BMDA 进行结构解析以评估吸附剂的结构。不同的实验特征，如搅拌时间、BMDA 剂量、温度、初始吸附物浓度和溶液的 pH 值，对污染物的吸收模式进行了检查。用 Elovich、伪一级、粒子内扩散和伪二级动力学模型检查吸附机制，同时利用 Langmuir、Dubinin-Radushkevich (DR)、Freundlich 和 Tempkin 等温线来描述吸附的行为。平衡过程。XRD 分析显示对应于单相磷灰石粉末的峰，而导致 BMDA 表面和污染物之间相互作用的各种力是通过 FT-IR 分析观察到的 CO 3 2- 、OH - 和 PO 4 3- 。SEM 和 TEM 研究证实了一种圆形形态，在吸附污染物时聚集在一起。吸附数据的动力学模型用相关系数 (R 2 ) 值在 0.997 到 0.999 范围内的准一级模型很好地说明了。等温线研究表明，Langmuir 等温线对 RY4 染料和 Cd(II) 离子的吸附容量分别为 94.85 和 116.16 毫克/克，达到了最佳拟合。热力学研究表明污染物的吸收是自发的、可行的和吸热的。计算出的吸附过程的熵变 (ΔS) 值为 86.57 和 60。