| 1. |
- Giongo, Adriana, et al.
(författare)
-
Adaption of microbial communities to the hostile environment in the Doce River after the collapse of two iron ore tailing dams
- 2020
-
Ingår i: Heliyon. - : Elsevier. - 2405-8440. ; 6:8, s. 1-16
-
Tidskriftsartikel (refereegranskat)abstract
- In November 2015, two iron ore tailing dams collapsed in the city of Mariana, Brazil. The dams' collapse generated a wave of approximately 50 million m(3) of a mixture of mining waste and water. It was a major environmental tragedy in Brazilian history, which damaged rivers, and cities 660 km away in the Doce River basin until it reached the ocean coast. Shortly after the incident, several reports informed that the concentration of metals in the water was above acceptable legal limits under Brazilian laws. Here the microbial communities in samples of water, mud, foam, and rhizosphere of Eichhornia from Doce River were analyzed for 16S and 18S rRNA-based amplicon sequencing, along with microbial isolation, chemical and mineralogical analyses. Samples were collected one month and thirteen months after the collapse. Prokaryotic communities from mud shifted drastically over time (33% Bray-Curtis similarity), while water samples were more similar (63% Bray-Curtis similarity) in the same period. After 12 months, mud samples remained with high levels of heavy metals and a reduction in the diversity of microeukaryotes was detected. Amoebozoans increased in mud samples, reaching 49% of microeukaryote abundance, with Discosea and Lobosa groups being the most abundant. The microbial communities' structure in mud samples changed adapting to the new environment condition. The characterization of microbial communities and metal-tolerant organisms from such impacted environments is essential for understanding the ecological consequences of massive anthropogenic impacts and strategies for the restoration of contaminated sites such as the Doce River.
|
|
| 2. |
- Vernooij, Roland, et al.
(författare)
-
CO2‐water‐rock interactions in undeformed and sheared claystone caprocks from Northern Europe
- 2021
-
Ingår i: Greenhouse Gases. - : John Wiley & Sons. - 2152-3878. ; 11:2, s. 232-250
-
Tidskriftsartikel (refereegranskat)abstract
- One of the most promising, cost-effective, and readily available technologies for reducing greenhouse gas emissions to the atmosphere is the capture and separation of CO2 from large stationary sources and storage in geological formations. Storage security, especially in the early stages of operation, is mostly guaranteed by caprock formations with very low permeability overlying the reservoir, capable of containing the injected fluid. Chemical alterations of the formation brine, caused by CO2 injection may cause dissolution and precipitation of secondary minerals, potentially increasing the risks of leakage from the reservoir. In order to evaluate these processes and their potential to induce the formation of leakage pathways in ultrafine fault gouges, a series of batch experiments was performed on crushed and sheared samples from three different caprock formations from Northern Europe (Sollingen, Rot and Opalinus claystones). The experiments were supported by numerical models of the kinetics of mineral dissolution and precipitation simulating the same experimental conditions, and over a longer time (10 000 years). Minor mineral alterations were observed after the batch experiments, the most important being: illite dissolution for the Opalinus and Rot formation samples, and dolomite dissolution and the transformation of illite and chlorite into kaolinite for the Sollingen sample.
|
|
