Nanoscale zerovalent iron (nZVI) has been investigated for the selective formation of Cu nanoparticles from acid mine drainage (AMD) taken from a legacy mine site in the UK. Batch experiments were conducted containing unbuffered (pH 2.67 at t=0) and pH buffered (pH <3.1) AMD which were exposed to nZVI at 0.1-2.0 g/L. Results demonstrate that nZVI is selective for Cu, Cd and Al removal (>99.9% removal of all metals within 1 h when nZVI ≥1.0 g/L) from unbuffered AMD despite the coexistent of numerous other metals in the AMD, namely: Na, Ca, Mg, K, Mn and Zn. An acidic pH buffer enabled similarly high Cu removal but maximum removal of only <1.5% and <0.5% Cd and Al respectively. HRTEM-EDS confirmed the formation of discrete spherical nanoparticles comprised of up to 68% wt. Cu, with a relatively narrow size distribution (typically 20-100 nm diameter). XPS confirmed such nanoparticles as containing Cu°, with the Cu removal mechanism therefore likely via cementation with Fe⁰. Overall the results demonstrate nZVI as effective for the one-pot and selective formation of Cu⁰-bearing nanoparticles from acidic wastewater, with the technique therefore potentially highly useful for the selective upcycling of dissolved Cu in wastewater into high value nanomaterials.

已经对纳米级零价铁（nZVI）进行了研究，以从英国一处遗留矿场中的酸性矿山排水（AMD）中选择性形成铜纳米颗粒。进行包含未缓冲的（t = 0时的pH 2.67）和pH缓冲的（pH <3.1）AMD的批量实验，将它们暴露于0.1-2.0 g / L的nZVI中。结果表明，nZVI具有选择性地从无缓冲AMD中去除Cu，Cd和Al（在1小时内所有金属中> 99.9％的去除），尽管AMD中同时存在多种其他金属，例如：Na，钙，镁，钾，锰和锌。酸性pH缓冲液可实现类似的高Cu去除率，但最大去除率分别仅为Cd和Al的<1.5％和<0.5％。HRTEM-EDS证实了不连续球形纳米颗粒的形成，其含量高达68％wt。铜 具有相对窄的尺寸分布（通常为20-100 nm直径）。XPS证实此类纳米颗粒含有Cu°，因此可能具有去除铜的机理通过与Fe ⁰胶结。总体而言，结果表明nZVI对于从酸性废水中一锅法和选择性地形成含Cu ^0的纳米颗粒有效，因此该技术对于将废水中溶解的Cu选择性地向上循环成高价值纳米材料具有潜在的实用价值。