Modern technology relies on an undisrupted supply of metals, yet many metals have limited geological deposits. Recovering metals from wastewater and brine could augment metal stocks, but there is little guidance on which metals to prioritize for recovery or on the techno-economic viability of extraction processes. Here we critically assess the potential for recovering metals from wastewater and brine. We first look at which metals are critical for recovery on the basis of their supply risks and the impacts of those supply restrictions. We then assess the feasibility of recovering these metals from various water sources by estimating the required operational costs to match market prices. Next we discuss the limitations of established separation technologies that may inhibit the practicality and scalability of metal recovery from water. We conclude by highlighting materials and processes that could serve as more sustainable alternatives to metal recovery with further research and development.

现代技术依赖于不间断的金属供应，但许多金属的地质储量有限。从废水和盐水中回收金属可以增加金属库存，但对于优先回收哪些金属或提取过程的技术经济可行性几乎没有指导。在这里，我们批判性地评估了从废水和盐水中回收金属的潜力。我们首先根据供应风险和这些供应限制的影响来研究哪些金属对复苏至关重要。然后，我们通过估算匹配市场价格所需的运营成本来评估从各种水源中回收这些金属的可行性。接下来，我们将讨论现有分离技术的局限性，这些局限性可能会阻碍从水中回收金属的实用性和可扩展性。