Skeletal remains collected from 46 Bohemian and Moravian ossuaries were of an age corresponding to cold climatic fluctuations in the past millennium. It seems that climatic events, associated with limited solar activity, influenced the production of plant food. The values of δ¹⁵N and δ¹³C have a linera dependence, indicating a predominant sources of protenins. Simultaneously, the compositions of the bone collagen exhibited differences in the isotopic compositions of C and N, which could be caused by the better management in smaller municipalities and as a consequence of the availability of plant protenins with a higher content of the heavier isotopes of nitrogen or greater availability of animal proteins.

Smrčka V., Mihaljevič M. (2024): Depositing sskeletal remains in Czech and Moravian ossuaries and associated climatic variations. Radiocarbon 66, 552-567. (DOI)

For the first time, copper isotopes (expressed as δ⁶⁵Cu) wer used as indicators of reactions occurring during the Cu-ore heap leaching, an in situ technological process used for extraction of this strategic metal. In comparison with unleached ore (average δ⁶⁵Cu  -1.47‰), leached ores exhibit lighter isotopic values (average δ⁶⁵Cu -6.01‰) and enrichment of the leachate in heavier ⁶⁵Cu isotope indicating a dissolution of primary Cu-bearing minerals along with an oxidation process. Our results, based on combined measurements of Cu isotopes and mineralogical investigation with geochemical modelling, can be used as analogy of Cu leaching in gossans. 

Sracek O., Ettler V., Mihaljevič M., Kříbek B., Mapani B., Penížek V., Zádorová T., Vaněk A. (2024): Identification of processes in Cu-ore heap leaching using Cu isotopes and leachate chemistry at Tschudi mine, northern Namibia. Hydrometallurgy 228, 106356. (DOI)

The significant release of arsenic observed from ferric arsenate minerals in the presence of elevated phosphate levels underscores the complexity of their stability in natural environments. Our findings highlight the need to reconsider phosphate treatments in extraction procedures involving ferric arsenates, emphasizing the importance of cautious application in managing polymetallic mine wastes. For sustainable land management, minimizing long-term phosphate additions to arsenic-contaminated soils and mine tailings containing ferric arsenates is crucial to mitigate As(V) export into surface waters and groundwater.

Petra Stubbe (Venhauerova), Irena Matulková, Christian Mikutta, Petr Drahota (2024): Dissolved phosphate decreases the stability of amorphous ferric arsenate and nano-crystalline yukonite. Journal of Hazardous Materials 471, 134374. (DOI)

Wastewater treatment plants are an important source of phosphorus to the environment. They are estimated to bring between 25 and 45 % of total phosphorus in freshwaters. This study describes how discharged phosphate releases arsenic from streambed sediments into freshwaters. After seven years, the concentration of total As in the streambed sediment below the wastewater treatment plant decreased by 25 % due competitive desorption of arsenate by phosphate.

Petra Venhauerova, Petr Drahota, Ladislav Strnad, Šárka Matoušková (2022): Effects of a point source of phosphorus on the arsenic mobility and transport in a small fluvial system. Environmental Pollution 315, 120477. (DOI)