ABSTRACT

The combined approach of specific surface area (SSA), porosity, microprobe analysis (EMPA), transmission electron microscopy (TEM), scanning electron microscopy (SEM) equipped with EDX and infrared spectroscopy (FTIR) provided the mica mineral physico-chemical and morphological characterisation. The electrostatic surface properties were assessed through the determination of the Point of Zero Charge (pH_PZC) by the drift method and the electrokinetic mica mineral features represented by the Isoelectric Point (pH_IEP) which was carried out through zeta potential measurements. Adsorption tests were performed to correlate the surface charge behaviour of the mica mineral and its influence on the adsorption efficiency of two different dyes, namely: Safranin Orange (SO), as a cationic dye and Reactive Black 5 (RB5), as an anionic dye. The higher adsorption capacity SO dye was observed at pH 9 and achieved almost 83% of removal, while RB5 dye adsorption on mica surface had the highest result, about 45% of removal efficiency, on pH of 3. In both cases, the main mechanism identified that drove this results is the electrostatic force of attraction between the adsorbent edge surface charge (pH-dependent) and the ionic nature (anionic or cationic) of the pollutant dyes particles. The preliminary adsorption experiments demonstrated that the raw grounded mica mineral has a greater potential associated with its application on cationic dye removal in wastewater. The present study aimed to detail the main characteristics of the mica mineral in order to evaluate the potential use of such mineral residues in the removal efficiency of contaminated wastewater.

摘要

比表面积 (SSA)、孔隙率、探针分析 (EMPA)、透射电子显微镜 (TEM)、配备 EDX 和红外光谱 (FTIR) 的扫描电子显微镜 (SEM) 的组合方法提供了云母矿物的物理化学和形态表征。通过漂移法测定零电荷点 (pH _PZC ) 和由等电点 (pH _{IEP ) 表示的电动云母矿物特征来评估静电表面性质}) 这是通过 zeta 电位测量进行的。进行吸附测试以关联云母矿物的表面电荷行为及其对两种不同染料吸附效率的影响，即：作为阳离子染料的番红橙 (SO) 和作为阴离子染料的活性黑 5 (RB5) . 在 pH 9 时观察到更高的 SO 染料吸附容量，去除率接近 83%，而在云母表面吸附 RB5 染料的结果最高，在 pH 为 3 时去除效率约为 45%。在这两种情况下，主要机制确定驱动该结果的是吸附剂边缘表面电荷（依赖于pH）与污染物染料颗粒的离子性质（阴离子或阳离子）之间的静电吸引力。初步吸附实验表明，未加工的接地云母矿物在去除废水中的阳离子染料方面具有更大的潜力。本研究旨在详细说明云母矿物的主要特征，以评估此类矿物残留物在污染废水去除效率中的潜在用途。