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Figure 1. 

Conceptual schematic of microbial iron mining for soil remediation. (a) Global observations of iron films in shallow water environments (n = 1,169; public data accessed from www.inaturalist.org/observations on June 13, 2025). (b) Examples of iron films. (c) Cross-sectional view of a waterlogged soil profile illustrates key steps in microbial iron mining. In the anaerobic reduction zone within the soil, ferric oxides are reduced to ferrous ions (Fe²⁺) by iron-reducing bacteria. The Fe²⁺ then diffuses through porewater toward oxic zones. At the oxic overlying water surface, Fe²⁺ is oxidized by oxygen or iron-oxidizing bacteria to form mixed-valence iron minerals. (d) During these processes, contaminants such as TMs, organic pollutants, ARGs, and nutrients are captured or degraded via adsorption, precipitation, or catalytic reaction mechanisms.