Gonçalves Nuno P F, Almeida Mariana M, Labrincha João A, Novais Rui M
Dept. of Chemistry/CICECO-Aveiro Institute of Materials, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
Dept. of Materials and Ceramic Engineering/CICECO-Aveiro Institute of Materials, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
Sci Total Environ. 2024 Aug 25;940:173633. doi: 10.1016/j.scitotenv.2024.173633. Epub 2024 May 31.
Acid mine drainage (AMD) poses a significant threat to water quality worldwide, being amongst the most problematic environmental concerns of the millennium. This work reports for the first time the remediation of real AMD, from a Portuguese abandoned mine, in fixed bed column using porous red mud/fly ash-based geopolymeric spheres. Porous waste-based spheres (2.6 ± 0.2 mm) were obtained by a suspension-solidification method through the addition of optimum foaming agent dosage. The sorbent capacity in removing cations from AMD was evaluated by targeting selected hazardous elements: Zn, Cu, Co, Pb and Ni, based on their occurrence in the effluent and potential hazard. The spheres exhibited a dual mechanism of action, simultaneously neutralizing the acidic sample while removing cations through adsorption achieving removal efficiencies between 51 % and 80 %. Other elements present in high levels, such as iron were efficiently removed (>96 %). The role of precipitation, due to the pH neutralization, and adsorption was determined. The sorbent regeneration and reusability were evaluated for up to five cycles. Moreover, the effectiveness of waste-based geopolymers treating distinct AMD waters due to seasonal variations was also evaluated, further demonstrating the effectiveness of the proposed strategy to address environmental concerns stemming from mining activities.
酸性矿山排水（AMD）对全球水质构成重大威胁，是千年以来最具问题的环境问题之一。这项工作首次报道了使用多孔赤泥/粉煤灰基地质聚合物球体在固定床柱中对来自葡萄牙废弃矿山的实际AMD进行修复。通过添加最佳发泡剂用量，采用悬浮固化法获得了多孔废物基球体（2.6±0.2毫米）。基于废水中选定有害元素（锌、铜、钴、铅和镍）的存在情况及其潜在危害，评估了从AMD中去除阳离子的吸附剂容量。这些球体表现出双重作用机制，在通过吸附去除阳离子的同时中和酸性样品，去除效率在51%至80%之间。其他含量较高的元素，如铁，也被有效去除（>96%）。确定了pH中和引起的沉淀作用和吸附作用。对吸附剂的再生和可重复使用性进行了多达五个循环的评估。此外，还评估了基于废物的地质聚合物因季节变化处理不同AMD水的有效性，进一步证明了所提出策略解决采矿活动引起的环境问题的有效性。
