| 1. |
- Medina-Silva, Renata, et al.
(författare)
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Microbiota associated with tubes of Escarpia sp. from cold seeps in the southwestern Atlantic Ocean constitutes a community distinct from that of surrounding marine sediment and water
- 2017
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Ingår i: Antonie van Leeuwenhoek. International Journal of General and Molecular Microbiology. - : Springer Science and Business Media LLC. - 0003-6072 .- 1572-9699. ; 111:4, s. 533-550
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Tidskriftsartikel (refereegranskat)abstract
- As the depth increases and the light fades in oceanic cold seeps, a variety of chemosynthetic-based benthic communities arise. Previous assessments reported polychaete annelids belonging to the family Siboglinidae as part of the fauna at cold seeps, with the ‘Vestimentifera’ clade containing specialists that depend on microbial chemosynthetic endosymbionts for nutrition. Little information exists concerning the microbiota of the external portion of the vestimentiferan trunk wall. We employed 16S rDNA-based metabarcoding to describe the external microbiota of the chitin tubes from the vestimentiferan Escarpia collected from a chemosynthetic community in a cold seep area at the southwestern Atlantic Ocean. The most abundant operational taxonomic unit (OTU) belonged to the family Pirellulaceae (phylum Planctomycetes), and the second most abundant OTU belonged to the order Methylococcales (phylum Proteobacteria), composing an average of 21.1 and 15.4% of the total reads on tubes, respectively. These frequencies contrasted with those from the surrounding environment (sediment and water), where they represent no more than 0.1% of the total reads each. Moreover, some taxa with lower abundances were detected only in Escarpia tube walls. These data constitute on the first report of an epibiont microbial community found in close association with external surface of a cold-seep metazoan, Escarpia sp., from a chemosynthetic community in the southwestern Atlantic Ocean.
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| 2. |
- Melo, Clarissa L., et al.
(författare)
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CO2MOVE Project : The New Brazilian Field Lab Fully Dedicated to CO2 MMV Experiments
- 2017
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Ingår i: 13th International Conference on Greenhouse Gas Control Technologies, GHGT-13. - : Elsevier. ; , s. 3699-3715
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Konferensbidrag (refereegranskat)abstract
- After the Ressacada Project experience acquired from 2011 to 2015 when PUCRS, UNESP and other institutions conducted three controlled CO2 release experiments, PETROBRAS, the national oil company that is sponsoring the project, has launched a new challenge to its partners. The company stimulated the implementation of a new Brazilian experimental site where there will be a deepening of studies in geologically more complex conditions and more challenging from a technological point of view. The choice of an area inside PUCRS campus, in Viamao - Rio Grande do Sul state, was motivated by a predominantly clay subsoil and the privileged location of the site in terms of ease logistics and security, which is required for a project of this size that houses high-tech equipment with significant cost. The CO2MOVE project started at 2015 with the subsurface characterization of the site and the assembly and manufacture of an automated system for CO2 and gas tracers with injection capacity for 5 to 50 kg/ day. Based on physical characterization studies and on numerical modeling that is being developed, the site infrastructure will be completed in the next months with the positioning of vertical injection wells, monitoring wells, and other equipment and monitoring mesh. Monitoring tools should be arranged in an area of approximately 100m(2), occupying the entire region surrounding the injection wells. Fieldwork involving CO2 injection and monitoring should have a 60 days duration of which 15 days are for preliminary surveys (pre-injection), 30 days for injection and CO2 monitoring and the last 15 days for post-injection measurements. Following this work, the collected data will be analyzed in the university labs. Similarly to Ressacada Project, this experiment will run measurements of soil CO2 flux with accumulation chambers, CO2 turbulent fluxes with Eddy Covariance, subsurface gases and groundwater monitoring, and resistivity measurements. Other monitoring methods still not tested by the research team will be held as gas tracers monitoring and laser measurements. (C) 2017 The Authors. Published by Elsevier Ltd.
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| 3. |
- Melo, Clarissa L., et al.
(författare)
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Integration results of soil CO2 flux and subsurface gases in the Ressacada Pilot site, Southern Brazil
- 2017
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Ingår i: 13th International Conference on Greenhouse Gas Control Technologies, GHGT-13. - : Elsevier. ; , s. 3793-3804
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Konferensbidrag (refereegranskat)abstract
- The first CO2 monitoring field lab at the Ressacada Farm, in the Southern region of Brazil, started in 2011 and until 2015 offered an excellent opportunity to run controlled CO2 releases experiments in soil and shallow subsurface through vertical injection wells. This paper focus on the presentation and comparison of the results obtained at the last campaign realized at this site in August 2015. The results integrate a time-lapse monitoring experiment of CO2 migration in both saturated and unsaturated sand-rich sediments and soil, using soil CO2 flux measurements and subsurface gas analyses through CO2 concentrations (ppm) and carbon isotope ratios (delta C-13 of CO2). The CO2 flux results in the studied area showed an increase in the flux values according to the increasing of injection rate and along the campaign are directed to the southwest portion of the area. However, even by injecting large amounts of CO2, fluxes are greatly reduced when it rains. The gas analysis also showed an increase in CO2 concentrations according to the increasing of the injection rate mainly in the superficial levels of the monitoring wells (0.5m and 2m depth). The delta C-13 of CO2 found on the 3rd injection day showed the presence of CO2 injected and demonstrate that the sampling methodology with vacutainer vial was effective, since there is no atmospheric contamination. The correlation of isotopic analysis were consistent with the results of concentrations and CO2 fluxes and thus, it is clear that the CO2 breakthrough occurred from the 3rd day of injection, while were obtained the largest CO2 fluxes, the higher gas concentrations in the subsurface, as well as the industrial origin of delta C-13 of CO2.
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| 4. |
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| 5. |
- Cedeno, Daniel Grings, et al.
(författare)
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An experimental study on smectites as nitrogen conveyors in subduction zones
- 2019
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Ingår i: Applied Clay Science. - : Elsevier. - 0169-1317 .- 1872-9053. ; 168, s. 409-420
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Tidskriftsartikel (refereegranskat)abstract
- We performed high pressure and high temperature (HPHT) experiments on NH4-doped montmorillonite (similar to 2 wt % of NH4) under pressures of 2.5, 4.0, and 7.7 GPa and temperatures from 200 to 700 degrees C. Each experiment was analyzed with XRD, FTIR, CHN elemental analysis, and SEM in order to determine the NH4-Smectite phase changes and their morphology, and the presence of ammonium in the runs. Our results show that smectite can easily transport nitrogen, speciated as ammonium (NH4+), incorporated into the smectite interlayer in mildly reducing environments to deeper levels in the Earth through cold thermal regime subduction zones. NH4-Smectite transforms into NH4-enriched micaceous phase (tobelite) through a NH4+-enriched interlayered I/S phase in relatively low pressures and temperatures (around 2.5 GPa and 500 degrees C). Tobelite is stable until more extreme conditions (7.7 GPa and 700 degrees C), together with lesser amounts of buddingtonite (an ammonium-bearing feldspar) kyanite, and garnet. Our experiments also show the effect of nitrogen in the feldspar stability, as potassic and sodic feldspar are stable up to similar to 5 GPa, while buddingtonite, is observed to be stable up to 7.7 GPa. Nitrogen can return to the surface once the stability of these nitrogen-enriched minerals is reached due to pressure or temperature increasing.
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| 6. |
- da S. Ramos, Alessandro, et al.
(författare)
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Comparative assessment between different sample preparation methodologies for PTGA CO2 adsorption assays—Pellet, powder, and fragment samples
- 2018
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Ingår i: Adsorption Science and Technology. - : Sage Publications. - 0263-6174 .- 2048-4038. ; 36:7-8, s. 1441-1455
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Tidskriftsartikel (refereegranskat)abstract
- The carbon dioxide sorption process at coal seams is very important for understanding the trapping mechanisms of carbon capture and storage. The gas retention capacity of coal seams can be estimated using indirect methods based on the adsorption/desorption isotherms obtained in the laboratory. However, the gas sorption capacity can be overestimated or underestimated depending on the sample preparation. This work evaluates different sample preparations and their theoretical adsorption capacity using coal samples from the Cambui coal field (Parana Basin), southern Brazil. Experiments using a thermogravimetric balance were done to calculate the theoretical adsorption capacity, while sample characterization was done through immediate analysis, elementary analysis, and mineralogical studies. The sample preparations used in this work were powder, pellets, and fragments. While the powder form presents an average behavior, without any experimental complication, the pellet is extremely sensitive to any variation in the sample preparation, such as fractures, and the fragment requires a much longer experiment time than the other sample preparations, being impracticable for some cases.
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| 7. |
- dos Santos, Victor Hugo J. M., et al.
(författare)
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Classification of Fuel Blends Using Exploratory Analysis with Combined Data from Infrared Spectroscopy and Stable Isotope Analysis
- 2017
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Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 31:1, s. 523-532
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Tidskriftsartikel (refereegranskat)abstract
- Chemometric tools were applied for exploratory analysis and classification of fuel blends using the combined information on Fourier transform infrared spectroscopy and stable isotope analysis through isotope ratio mass spectrometry. Principal component analysisand hierarchical clustering analysis were applied for exploratory analysis, while support vector machine (SVM) was used to classify the biodiesel/diesel blends. All of the chemometric models used present better results from the combination of spectral information with isotopic data for biodiesel contents of over 10% in the mixture, with the best results being Obtained from the SVM classification. Therefore, the development presented in this paper could become an important technique to improve the discrimination of the feedstock used in biodiesel production and a resource for quality control in industry.
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| 8. |
- dos Santos, Victor Hugo J. M., et al.
(författare)
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Discriminant analysis of biodiesel fuel blends based on combined data from Fourier Transform Infrared Spectroscopy and stable carbon isotope analysis
- 2017
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Ingår i: Chemometrics and Intelligent Laboratory Systems. - : Elsevier. - 0169-7439 .- 1873-3239. ; 161, s. 70-78
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Tidskriftsartikel (refereegranskat)abstract
- A multivariate approach was used for classification of fuel blends using the combined information from Fourier Transform Infrared Spectroscopy (FTIR) and stable carbon isotopes analysis by Isotope Ratio Mass Spectrometry (IRMS). Linear Discriminant Analysis (LDA) and Partial Least Squares Discriminant Analysis (PLS-DA) were applied to the classification of biodiesel/diesel fuel blends containing 0-100% (v/v) of biodiesel. The LDA and PLS-DA methods were able to discriminate samples ranging from 10% to 100% biodiesel (v/v) using the combined information from FTIR and IRMS. Since the global trend is toward a gradual increase in the percentage of biodiesel in fuel blends, the technique presented in this paper could be an important development in improving the traceability and identification of different raw materials used in biodiesel production.
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| 9. |
- Engelmann, Pâmela de Medeiros, et al.
(författare)
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Environmental monitoring of a landfill area through the application of carbon stable isotopes, chemical parameters and multivariate analysis
- 2018
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Ingår i: Waste Management. - : Elsevier BV. - 0956-053X .- 1879-2456. ; 76, s. 591-605
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Tidskriftsartikel (refereegranskat)abstract
- Leachate produced during an organic matter decomposition process has a complex composition and can cause contamination of surface and groundwaters adjacent to a landfill area. The monitoring of these areas is extremely important for the characterization of the leachate produced and to avoid or mitigate environmental damages. Thus, the present study has the objective of monitoring the area of a Brazilian landfill using conventional parameters (dissolved metals and anions in water) and alternative, stable carbon isotopes parameters (δ13C of dissolved organic and inorganic carbons in water) in addition to multivariate analysis techniques. The use of conventional and alternative parameters together with multivariate analysis showed that cells of the residues are at different phases of stabilization of the organic matter and probably already at C3 of the methanogenic phase of decomposition. In addition, the data showed that organic matter stabilization ponds present in the landfill are efficient and improve the quality of the leachate. Enrichment of the heavy 13C isotope in both surface and groundwater suggested contamination in two sampling sites.
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| 10. |
- Engelmann, Pamela de Medeiros, et al.
(författare)
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Environmental monitoring of water resources around a municipal landfill of the Rio Grande do Sul state, Brazil
- 2017
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Ingår i: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; 24:26, s. 21398-21411
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Tidskriftsartikel (refereegranskat)abstract
- In Brazil, landfills are commonly used as a method for the final disposal of waste that is compliant with the legislation. This technique, however, presents a risk to surface water and groundwater resources, owing to the leakage of metals, anions, and organic compounds. The geochemical monitoring of water resources is therefore extremely important, since the leachate can compromise the quality and use of surface water and groundwater close to landfills. In this paper, the results of analyses of metals, anions, ammonia, and physicochemical parameters were used to identify possible contamination of surface water and groundwater in a landfill area. A statistical multivariate approach was used. The values found for alkali metals, nitrate, and chloride indicate contamination in the regional groundwater and, moreover, surface waters also show variation when compared to the other background points, mainly for ammonia. Thus, the results of this study evidence the landfill leachate influence on the quality of groundwater and surface water in the study area.
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