Departamento de Ingeniería Química y Ambiental, Escuela Técnica Superior de Ingeniería, Universidad de Sevilla, C/Camino de los Descubrimientos s/n, Sevilla 41092, España.
Environ Sci Technol. 2020 Sep 1;54(17):10936-10943. doi: 10.1021/acs.est.0c03392. Epub 2020 Aug 11.
In this work, a novel study for acid mine drainage remediation and reutilization by means of a forward osmosis technology is addressed. The proposed process is a potential alternative path, which allows to recover high-quality water and to concentrate metals for its possible reutilization as synthetic minerals. This novel process will help in the mining industry evolving toward more sustainable processes and favors circular economy policies. Four inorganic salts (NaCl, KCl, CaCl, and MgCl) were evaluated as draw solutions from 1 to 5 M concentrations, in terms of water flux, water recovery, and metal rejection, using a thin-film composite (TFC) membrane. Water flux obtained was in the range of 14-53 L/(m h). The highest water flux was found for MgCl, whereas the lowest correspond to KCl. The metal rejection obtained was greater than 99%. After a discussion and comparison of the results, MgCl was chosen for evaluating long-term assay performance. Scanning electron microscope images of the thin-film composite membrane after long-term assays were taken. The tendency of Mg-Ca and Al-Fe fouling was observed over the membrane surface. The energy consumption was estimated from 4.84-22.3 kWh/m, assuming that osmotically assisted reverse osmosis is used to regenerate the draw solution.
本工作提出了一种利用正向渗透技术修复和再利用酸性矿山排水的新研究。所提出的工艺是一种潜在的替代途径，可以回收高质量的水，并浓缩金属，以可能将其再利用为合成矿物。这种新颖的工艺将有助于矿业向更可持续的工艺发展，并有利于循环经济政策。评估了四种无机盐（NaCl、KCl、CaCl 和 MgCl）作为汲取液，浓度为 1 到 5 M，考察了水通量、水回收率和金属截留率，使用了一种薄膜复合（TFC）膜。获得的水通量在 14-53 L/（m h）之间。MgCl 的水通量最高，而 KCl 的水通量最低。金属截留率大于 99%。在对结果进行讨论和比较后，选择 MgCl 来评估长期试验性能。对长期试验后的薄膜复合膜进行了扫描电子显微镜图像拍摄。观察到膜表面存在 Mg-Ca 和 Al-Fe 结垢的趋势。假设使用渗透压辅助反渗透来再生汲取液，估计能耗为 4.84-22.3 kWh/m。
