Departamento de Ingeniería Civil y Centro de Recursos Hídricos para el Agua y la Minería (CRHIAM), Universidad de Concepción, Barrio Universitario, Concepción, Chile.
Facultad de Ingeniería y Tecnología, Universidad San Sebastián, Lientur 1457, Concepción, Chile.
Sci Total Environ. 2019 Mar 10;655:374-383. doi: 10.1016/j.scitotenv.2018.11.083. Epub 2018 Nov 8.
This research studied the bio-protection mechanism based on chemical gradients in diffusive exchange permeable reactive barriers, evaluating the thickness of the reactive layers in the treatment of concentrated acid mine drainage (AMD). Six bench-scale reactors were constructed with reactive layer thicknesses of 2.5, 5, and 7.5 cm in duplicate. The reactors were first fed a sulfated solution for 55 days, followed by concentrated AMD for 166 days. The change of feed to AMD mainly affected the reactors with thinner 2.5 cm layers in comparison to the reactors with 5 and 7.5 cm layers. Cu and Zn removal efficiency was practically 100% in all the reactors; however, in the thinner layer reactors, metal breakthrough occurred towards the end of the experiment concurrently with inhibitory metal concentrations in the reactive layers. On the contrary, the reactors with layer thicknesses of 5 and 7.5 cm evaluated did not present toxic concentrations of these metals at any of the monitoring points. The bio-protection criterion q correctly predicted that the thin-layer reactor would be the most affected by the toxicity of AMD. The criterion also indicated that all the reactors should fail. Nevertheless, the fault in the thinner layer reactor registered in the effluent after >150 days; therefore, the possibility of failure in the 5 and 7.5 cm thickness reactors is not rejected, as it could have occurred if the experiment had continued.
本研究基于扩散交换可渗透反应屏障中的化学梯度，研究了生物保护机制，评估了处理集中酸性矿山排水 (AMD) 的反应层厚度。构建了 6 个具有 2.5、5 和 7.5cm 反应层厚度的台式反应器，一式两份。这些反应器首先用硫酸盐溶液进料 55 天，然后用浓缩 AMD 进料 166 天。进料向 AMD 的变化主要影响了较薄的 2.5cm 层的反应器，与 5 和 7.5cm 层的反应器相比。所有反应器的 Cu 和 Zn 去除效率均接近 100%；然而，在较薄的层反应器中，金属突破发生在实验的最后阶段，同时反应层中的金属浓度受到抑制。相反，评估的 5 和 7.5cm 层厚的反应器在任何监测点均未出现这些金属的毒性浓度。生物保护标准 q 正确预测了薄层层反应器将受到 AMD 毒性的最大影响。该标准还表明所有反应器都将失效。然而，在 >150 天后，在流出物中记录到较薄层反应器出现故障；因此，不能排除 5 和 7.5cm 厚度反应器失效的可能性，如果实验继续进行，可能会发生这种情况。
