Remediation of acid mine drainage water using selective metal-harvesting membranes

PROJECT SUMMARY Acid mine drainage (AMD) is one of mining’s biggest environmental by-products and has contaminated thousands of kilometers of waterways globally. This pollution is devastating to the environment, wildlife, and human health. However, current AMD-remediation technologies are expensive and do not effectively solve the issue, due to the generation of large amounts of secondary streams with high concentrations of heavy metals (e.g., sludge). Towards a solution, the proposed project goal is to develop our patented membrane-based separation process, Ion-Capture Electrodialysis (IC-ED), for AMD remediation, demonstrating simultaneous desalination and metal recovery using a lab-scale prototype. Our innovative technology has the potential to significantly reduce costs, energy consumption, and waste generation related to AMD remediation by the integration of multiple processes into a single step. These environmental and economic advantages of our next- generation technology align with the NIEHS mission and the objectives of the Superfund Research Program in developing technologies that protect health and the environment, especially those related to mining- contaminated waters. The proposed project aims to demonstrate the feasibility of our technology under AMD- relevant conditions and treatment processes, helping to bridge the gap between research and commercialization—a critical step towards achieving environmental sustainability and commercial viability. Our first project aim is to optimize our fabrication methods for pilot-scale production, ensuring that the high performance of our novel metal-harvesting membranes is maintained. Once this is achieved, we will incorporate these materials into a continuous, lab-scale IC-ED system. Our testing will proceed in stages: initially with ideal solutions, containing only copper, and subsequently with synthetic or real AMD solutions. We aim to optimize system parameters to achieve at least a 90% copper capture rate and at least a 90% desalination rate, processing at a minimum flow rate of 1 liter per day. Additionally, demonstrating the reusability of our materials to minimize process downtime is crucial. Thus, we will focus on showing that the membranes can be regenerated by developing methods to recover the captured copper. This phase will examine both in-situ and ex-situ regeneration methods, with success defined by maintaining at least 90% of the original performance rates in terms of copper capture and desalination. Achieving these aims will validate the feasibility of our technology for AMD treatment applications and enable us to advance our long-term goals of mitigating the environmental impact of AMD.