酸性矿山排水(AMD)是与采矿活动相关的主要环境问题之一,无论矿井是在运行还是废弃。在这项工作中,由硫化物矿物氧化产生的这种矿井排水中的几种沉淀物,当暴露于风化时,用作吸附剂。这种AMD沉淀来自废弃的葡萄牙矿山(AGO,AGO-1、CF、和V9)与摩洛哥的两种原料(ClayMA和叶蜡石)在废水处理效率方面进行了比较。不同的分析技术,如XRD衍射(XRD),傅里叶变换红外光谱(FTIR),N2吸附等温线,使用具有能量色散X射线(EDX)的扫描电子显微镜(SEM)来表征这些天然材料。通过对不同实验因素的优化,研究了吸附性能,例如吸附剂的类型,吸附剂质量,通过Box-Behnken设计模型和染料浓度,使用亚甲基蓝(MB)和结晶紫(CV)化合物作为有机污染物。使用伪一阶和伪二阶方程检查获得的动力学数据,并使用Freundlich和Langmuir模型研究了平衡吸附数据。通过伪二级动力学模型和Langmuir等温线完美拟合了不同吸附剂的吸附行为。由于纤维素分子的存在,两种染料最有效的吸附剂是AGO-1,对于CV和MB,qm等于40.5和16.0mg/g,分别。这项研究证实了使用AMD沉淀物吸附水中有机污染物的可能性,为开发未来负担得起的解决方案提供有价值的信息,以减少与采矿活动相关的废物。
Acid mine drainage (AMD) is one of the main environmental problems associated with mining activity, whether the mine is operational or abandoned. In this work, several precipitates from this mine drainage generated by the oxidation of sulfide minerals, when exposed to weathering, were used as adsorbents. Such AMD precipitates from abandoned Portuguese mines (AGO, AGO-1, CF, and V9) were compared with two raw materials from Morocco (ClayMA and pyrophyllite) in terms of their efficiency in wastewater treatment. Different analytical techniques, such as XRD diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), N2 adsorption isotherms, and Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray (EDX) were used to characterize these natural materials. The adsorption properties were studied by optimizing different experimental factors, such as type of adsorbent, adsorbent mass, and dye concentration by the Box-Behnken Design model, using methylene blue (MB) and crystal violet (CV) compounds as organic pollutants. The obtained kinetic data were examined using the pseudo-first and pseudo-second order equations, and the equilibrium adsorption data were studied using the Freundlich and Langmuir models. The adsorption behavior of the different adsorbents was perfectly fitted by the pseudo-second order kinetic model and the Langmuir isotherm. The most efficient adsorbent for both dyes was AGO-1 due to the presence of the cellulose molecules, with qm equal to 40.5 and 16.0 mg/g for CV and MB, respectively. This study confirms the possibility of employing AMD precipitates to adsorb organic pollutants in water, providing valuable information for developing future affordable solutions to reduce the wastes associated with mining activity.