Karanac Milica, Đolić Maja, Veljović Đorđe, Rajaković-Ognjanović Vladana, Veličković Zlate, Pavićević Vladimir, Marinković Aleksandar
Innovation Center of the Faculty of Technology and Metallurgy Ltd. In Belgrade, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Serbia.
Vinča Institute of Nuclear Sciences, University of Belgrade, P.O. Box 522, 11001 Belgrade, Serbia.
Waste Manag. 2018 Aug;78:366-378. doi: 10.1016/j.wasman.2018.05.052. Epub 2018 Jun 22.
This study focuses on the use of raw fly ash (FA) and modified fly ash - activated by lime (MFA), as effective and low-cost adsorbents for the removal of heavy metals (Zn, Pb and As(V)), followed by the revalorization of the exhausted adsorbent. The granulometric, elemental analysis, point of zero charge (pH), radiochemical and structural characterization were conducted using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and gamma spectrometry techniques. The optimal conditions and key factors influencing the adsorption process were assessed using the response surface method (RSM). The adsorption capacity of the MFA adsorbent for Zn, Pb and As(V) removal, calculated by the Langmuir model, was found to be 33.13, 26.06, and 29.71 mg g, respectively. The kinetic and thermodynamic parameters indicated that the adsorption process is spontaneous and endothermic. Due to their low desorption potential of the exhausted adsorbents, their effective reuse was established to be feasible. For this reason, the valorization of this material as an additive in construction materials was thereafter studied, where testing its toxicity leaching (TCLP) as well as the mechanical properties of construction material containing exhausted MFA confirmed its safe use. Hence, this study points to a possible "two-in-one" reuse of coal ash, initially as an adsorbent and later as an additive in a construction material.
本研究聚焦于使用生粉煤灰（FA）和经石灰活化的改性粉煤灰（MFA）作为有效且低成本的吸附剂来去除重金属（锌、铅和砷（V）），随后对耗尽的吸附剂进行再利用。使用X射线衍射（XRD）、布鲁诺尔-埃米特-泰勒（BET）、扫描电子显微镜（SEM）、傅里叶变换红外光谱（FTIR）和伽马能谱技术进行粒度分析、元素分析、零电荷点（pH）、放射化学和结构表征。采用响应面法（RSM）评估影响吸附过程的最佳条件和关键因素。通过朗缪尔模型计算得出，MFA吸附剂对锌、铅和砷（V）的去除吸附容量分别为33.13、26.06和29.71 mg/g。动力学和热力学参数表明吸附过程是自发的且吸热的。由于耗尽的吸附剂解吸潜力低，证实其有效再利用是可行的。因此，此后研究了将该材料作为建筑材料添加剂的再利用，测试其毒性浸出（TCLP）以及含耗尽MFA的建筑材料的力学性能证实了其安全使用。因此，本研究指出了粉煤灰可能的“二合一”再利用方式，最初作为吸附剂，后来作为建筑材料中的添加剂。
