The role of authigenic sulfides in immobilization of potentially toxic metals in the Bagno Bory wetland, southern Poland

Abstract

The supply of Cd, Cu, Fe, Pb, Zn, and Tl into a wetland in the industrial area of Upper Silesia, southern Poland via atmospheric precipitation and dust deposition has been counterbalanced by the biogenic metal sulfide crystallization in microsites of the thin (<30 cm) peat layer, despite the overall oxidative conditions in the wetland. Disequilibrium of the redox reactions in the peat pore water (pH 5.4–6.2) caused by sulfate-reducing microorganisms has resulted in the localized decrease in Eh and subsequent precipitation of micron- and submicron-sized framboidal pyrite, spheroidal ZnS and (Zn,Cd)S, and galena as revealed by high-resolution scanning electron microscopy (SEM)/energy dispersive spectrometer (EDS). Saturation index for each sulfide is at a maximum within the calculated Eh range of −80 and −146 mV. Lead was also immobilized in galena deposited in fungal filaments, possibly at a higher Eh. Thallium (up to 3 mg kg−1) in the peat strongly correlates with Zn, whereas Cu (up to 55 mg kg−1) co-precipitated with Pb. The metal sulfides occur within microbial exudates, which protect them from oxidation and mechanical displacement. Vertical distribution of toxic metals in the peat layer reflects differences in pollution loads from atmospheric deposition, which has been much reduced recently.Electronic supplementary materialThe online version of this article (doi:10.1007/s11356-015-4728-8) contains supplementary material, which is available to authorized users.

Radiocarbon and lead-210 age-depth model and trace elements concentration in the Wolbrom fen (S Poland)

“…The highest accumulation rate occurs in the upper part of the profile (from approximately 10 cm depth to the top which corresponds with last 200 years (according to 210 Pb dates). Next, the mean (Śmieja-Król et al, 2015). However, the concentration of Pb and Zn is much higher than mean values for peatlands in Poland.…”

Natural attenuation can lead to environmental resilience in mine environment

“…These field evidences, together with the development of vegetal coverage and the hyporheic zone, indicated that Juncus acutus is the pioneer Zn tolerant plant, and that the growth of Phragmites australis follows, as the system stabilizes. The presence of authigenic metal sulphide minerals indicates the attenuation of metal loads, however they could be a sink of pollutants in case of changes of redox conditions and subsequent sulphide oxidation (Smieja-Król et al, 2015;Noel et al, 2017). The persistence of favourable conditions (pH, Eh, vegetal coverage, microbial activity, etc.)…”

“…Engineered and natural wetlands are ecosystems resilient to mine pollution as they allow bioprecipitation and immobilization of metals in sediments below the redox interface, where reducing conditions and availability of electron donors allow sulphur-reducing bacteria to produce sulphide ions that combine with metals to form biomineralization rich in base metal sulphides (Smieja-Król et al, 2015;De Giudici et al, 2017). Environmental resilience can be then tightly related to mineral dissolution or precipitation, particularly when mineral reactions decrease bioavailability of metals.…”

Influence of Wooden Sawdust Treatments on Cu(II) and Zn(II) Removal from Water

“…These contaminants mostly present in the acid mine drainage of closed copper and zinc mines [13][14][15]. Previous research [3][4][5]16] was dedicated to AMD monitoring and treatment.…”