To remediate surface water as the Doce River and spring waters from Minas Gerais, Brazil, this study examined the possibility of natural serpentinite mining tailings as a sustainable alternative for removing aluminum (III), iron (III), and manganese (II). The study used a Box-Behnken experimental design to examine how initial metal concentration, adsorbate dosage, and adsorption time affect metal removal effectiveness. Results demonstrated impressive performance, with removal rates exceeding 80 % for Al(III) and Fe(III) within the initial 5 min, and 60 % for Mn(II) within 30 min. This study delves deeper into the removal mechanisms, kinetics, adsorption isotherms and characterization identify physisorption and chemisorption pathways in which complex formation with released OH− groups and ion exchange with Mg(II) from serpentinite emerged as key contributors to the removal process. Furthermore, ion metal adsorption and regeneration cycles were assessed, exhibit sustained removal efficacy without notable capacity reduction. Each cycle shows an average metal adsorption capacity of 0.32 mg g−1 and an average Mg(II) release capacity of 0.98 mg g−1. Remarkably, the application of serpentinite successfully lowered the metals content of the Doce River and spring water to drinkable standards. A batch and continuous process is proposed for scaling-up serpentinite's metal adsorption. Overall, this study shows serpentinite's potential as a foundation for sustainable and cost-effective methods to treat surface water contamination with Al(III), Fe(III), and Mn(II).

中文翻译：

---

使用可持续的天然蛇纹石开采尾矿去除铝 （III）、铁 （III） 和锰 （II） 的地表水，概念验证


为了修复多斯河和巴西米纳斯吉拉斯州泉水等地表水，本研究考察了天然蛇纹石开采尾矿作为去除铝 （III）、铁 （III） 和锰 （II） 的可持续替代方案的可能性。该研究使用 Box-Behnken 实验设计来检查初始金属浓度、吸附物剂量和吸附时间如何影响金属去除效果。结果显示，性能令人印象深刻，在最初的 5 分钟内，Al（III） 和 Fe（III） 的去除率超过 80%，在 30 分钟内，Mn（II） 的去除率超过 60%。本研究更深入地探讨了去除机制、动力学、吸附等温线和表征，确定了物理吸附和化学吸附途径，其中蛇纹石中释放的 OH− 基团的复合物形成和与蛇纹石中 Mg（II） 的离子交换成为去除过程的关键贡献者。此外，评估了离子金属吸附和再生循环，表现出持续的去除效果，而容量没有显着降低。每个循环显示平均金属吸附容量为 0.32 mg g-1 和平均 Mg（II） 释放容量为 0.98 mg g-1。值得注意的是，蛇纹石的应用成功地将多斯河和泉水的金属含量降低到可饮用的标准。提出了一种批量和连续工艺来扩大蛇纹石的金属吸附。总体而言，本研究显示了蛇纹石作为可持续且具有成本效益的方法处理 Al（III）、Fe（III） 和 Mn（II） 地表水污染的基础的潜力。