Redox-driven geochemical partitioning of metal(loid)s in the iron-rich anoxic sediments of a recently flooded lignite mine pit: Lake Medard, NW Czechia

Anaerobic dissolved As(iii) removal from metal-polluted waters by cathode-stabilized Fe(iii)-oxyhydroxides

“…S2†). 34–36 In this “natural” aqueous system, slight variations in the redox conditions augmented the affinity of dissolved As for highly redox reactive amorphous Fe( iii ) oxyhydroxides that form and are readily transformed in transit between the redoxcline and the sediment–water interface. 35,36…”

“…34,36 In addition, the anoxic lake sediments exhibit As enrichment into easily reducible and highly crystalline Fe( iii ) oxyhydroxides. 35…”

“…34,36 In addition, the anoxic lake sediments exhibit As enrichment into easily reducible and highly crystalline Fe(III) oxyhydroxides. 35 In November 2019, the redox stratified bottom water column at the central area of Lake Medard was characterized by using a multiparameter sonde (6600 V2-2, YSI, USA). This was followed by bottom water sampling for cation and anion concentration analyses.…”

“…34 Minor changes in the redox state of the water column affect As speciation and, at times augment the release of As from the sediments. 35 In this model site, arsenic and iron are rapidly cycled between the sediment-water interface and the aqueous redoxcline. 34,36 Another relevant feature that influences the cycling of iron and arsenic in Lake Medard is the coexistence of dissolved inorganic N species.…”

Aqueous system-level processes and prokaryote assemblages in the ferruginous and sulfate-rich bottom waters of a post-mining lake

“…Details on the eastern and western sampling locations are available in a descriptive study by Petrash et al (2018). Short-lived changes in redox potential of the bottom water column were recently considered by Umbría-Salinas et al (2021). These changes have effects on the partitioning of several redox sensitive metals that are bound to reactive iron phases in the upper sediments.…”