On Thursday June 13, 2024, Petra Stubbe successfully defended her PhD thesis entitled “Effects of phosphate on the mobility of arsenic in contaminated areas”. Congratulations, Petra!
Petra with reviewers of the doctoral thesis, prof. Alexandra Courtin-Nomade (Université Paris-Saclay), prof. Edgar Hiller (Univerzita komenského v Bratislave), and her supervisor, Petr Drahota.
EGG is actively involved in the objective of the OP JAK project (Natural and anthropogenic georisks; project number: CZ.02.01.01/00/22_008/0004605). Within Work Package 5 (Geochemical risks and contaminations), our researchers will delve into following areas:
The researchers contributing to this project include: Martin Mihaljevič, Vojtěch Ettler, Petr Drahota, Maria Vaňková, Filip Košek, Adam Culka, Marek Tuhý, Petr Fleissig, and Martin Lichovník. EGG is set to collaborate closely with the Czech University of Life Sciences (Department of Pedology and Soil Protection) and Masaryk University (Recetox). As part of our initiative, the project aims to enhance the infrastructure and laboratories, particularly focusing on ICP MS, XRD, and Raman spectrometry.
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)
On December 14, 2022, Rafael Baieta successfully defended his PhD thesis entitled “A study of the behavior of selected metals in affected environments using isotopic approach” completed under supervision of prof. Martin Mihaljevič. On the photo you find Rafael with the external reviewers Dr. Tomáš Navrátil (left) and Dr. Václav Tejnecký (right). Congratulations, Rafael!
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)
On Thursday 22nd September 2022, Helena Jelenová (née Kindlová) and Magdaléna Peřestá (née Knappová) successfully defended their PhD theses entitled “Arsenic speciation in mining wastes – case studies in systems dominated by ferric sulfo-arsenates” and “Speciation of arsenic under reducing conditions of organic-rich soil”, respectively. Both theses were supervised by Dr. Petr Drahota. On the photos you will see both ladies with their supervisor and reviewers Dr. Michal Filippi (Geological Institute of the CAS), Dr. Ľubomír Jurkovič (Comenius University, Bratislava), Prof. Edgar Hiller (Comenius University, Bratislava) and Dr. Barbora Doušová (University of Chemistry and Technology Prague). It was a successful ARSENIC DAY. Congratulations!
This study explores the oxidation of arsenopyrite (FeAsS) and löllingite (FeAs2) at high relative humidity (RH: 75%-100%). Long-term oxidation (40 months) experiments show that oxidation of arsenopyrite and löllingite led to formation of different assemblages of secondary phases. Arsenopyrite oxidized to poorly-crystalline ferric arsenate, while löllingite oxidized to scorodite (FeAsO4·2H2O) and arsenolite (As2O3). Our results showed that the exposure of arsenopyrite and löllingite to different RH levels significantly influenced the amounts of newly formed phases. The major environmental impact of sulfide weathering occurs in well aerated environments characterized by high humidity – such as underground workings and some unsaturated mine wastes and tailings deposits.
Drahota, P., Ettler, V., Culka, A., Rohovec, J., Jedlička, R. (2022): Effect of relative humidity on oxidation products of arsenopyrite and löllingite. Chemical Geology 605, 120945. (DOI)
