Adeogun Abideen Idowu, Ofudje Edwin Andrew, Idowu Mopelola Abidemi, Kareem Sarafadeen Olateju, Vahidhabanu Shappur, Babu B Ramesh
Department of Chemistry and Department of Microbiology, Federal University of Agriculture, Abeokuta, Nigeria.
Department of Chemical Sciences, McPherson University, Abeokuta, Nigeria.
ACS Omega. 2018 Feb 16;3(2):1991-2000. doi: 10.1021/acsomega.7b01768. eCollection 2018 Feb 28.
This study examines the application of poultry eggshell (PES) as a source of calcium for the synthesis of hydroxyapatite (HA) via annealation. The synthesized powder (poultry eggshell hydroxyapatite (PESHA)) was characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), EDAX, and transmission electron microscopy (TEM) analytical techniques. This powder was used for adsorptive removal of the Reactive Yellow 4 (RY4) dye in a batch process. Results from morphological analysis by SEM and TEM revealed that the microstructure of the apatite is made up of needle-rod-like particles with the length of 15-60 nm, breadth of 4-6 nm, and crystallite size of 86.32 nm. EDAX revealed that HA has Ca/P ratio of 1.63, indicating a nonstoichiometric apatite, whereas XRD analysis presented it as a pure monophasic hydroxyapatite powder. Fourier Transform Infrared (FTIR) spectroscopy indicated that the adsorption is due to the electrostatic interaction between the functional groups of the dye and those on the apatite surface. The maximum adsorption capacity ( ) of 127.9 mg g was obtained for the adsorption process, whereas the pseudo-first-order model with > 0.99 best described the adsorption mechanism. Furthermore, the thermodynamic studies revealed that the adsorption process was exothermic and spontaneous in nature with Δ and Δ values of 120.79 kJ mol and 0.395 kJ mol K, respectively. Thus, hydroxyapatite fabricated from the poultry waste of eggshell can be effectively utilized as an excellent nontoxic and cheap adsorbent for the removal of RY4 dye from aqueous medium.
本研究考察了通过退火将禽蛋壳（PES）作为钙源用于合成羟基磷灰石（HA）。采用X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）、能谱分析（EDAX）和透射电子显微镜（TEM）分析技术对合成的粉末（禽蛋壳羟基磷灰石（PESHA））进行了表征。该粉末用于间歇过程中吸附去除活性黄4（RY4）染料。SEM和TEM的形态分析结果表明，磷灰石的微观结构由针状颗粒组成，长度为15 - 60 nm，宽度为4 - 6 nm，微晶尺寸为86.32 nm。EDAX显示HA的Ca/P比为1.63，表明是一种非化学计量磷灰石，而XRD分析表明它是一种纯单相羟基磷灰石粉末。傅里叶变换红外光谱（FTIR）表明，吸附是由于染料官能团与磷灰石表面官能团之间的静电相互作用。吸附过程的最大吸附容量（ ）为127.9 mg g，而相关系数 > 0.99的准一级模型能最好地描述吸附机理。此外，热力学研究表明，吸附过程是放热的且自发进行，Δ 和Δ 值分别为120.79 kJ mol和0.395 kJ mol K。因此，由禽蛋壳废弃物制备的羟基磷灰石可有效用作一种优良的无毒且廉价的吸附剂，用于从水介质中去除RY4染料。
