About the lab

- Estudio de gases de efecto invernadero (GEIs) y otros contaminantes atmosféricos de diversas fuentes y sumideros:
Flujos de GEIs en suelos bajo distintas coberturas vegetales;
Emisiones de CH4, CO2, NOx y SOx desde fuentes urbanas
Emisiones fugitivas de CH4 por uso de gas natural en centros urbanos
Emisiones de CH4 y N2O desde excretas y orina de animales en pastoreo o en feedlots
-Estudio de Procesos Avanzados de Oxidación aplicados al tratamiento químico de contaminantes difícilmente degradables en plantas de depuración biológica
- Desarrollo de tecnologías para recolección de muestras gaseosas y conservación de muestras de aire con trazas de distintos GEIs y desarrollo de cápsulas liberadoras de SF6, para medición de flujos de CH4 de rumiantes en pastoreo.

Featured research (21)

Upland soils are the only known biological sink for methane (CH 4 ) by methanotrophic bacteria consumption. This process is mainly limited by the diffusion processes related to the soil's physical characteristics, which can be modified because of changes in land use depending on the soil type, the original system and the new land use converted. Our study focused on determining the differences in soil CH 4 uptake because of changes in land use (from natural grassland to agricultural land and two Pinus radiata afforestation, differing in thinning management) and on determining which are the main drivers that control CH 4 uptake in the studied soil type (Hapludoll), with focus on the diffusion process. CH 4 fluxes were measured 12 times with the static chamber technique between October 2015 and April 2019. Also, CH 4 gradient concentration in the soil profile and physical and chemical variables were measured on the same dates. All land uses studied acted as net CH 4 sinks. Land‐use change from grassland to agriculture decreased soil CH 4 uptake (~37% ± 19), whereas afforestation increased (~85% ± 73) this environmental service related to natural grassland. We found that the main drivers that control CH 4 uptake in this soil are water and air‐filled pore space, variables that govern soil CH 4 diffusion; they are mostly related to differences in bulk density (compaction) among land uses. Organic matter was also an important driver, mainly related to soil structure. Land‐use change affected all of these drivers. CH 4 concentration presented differences at deeper soil layers only in the two afforestations, which differed in management (pruning and thinning vs. no management). However, CH 4 uptake did not present significant differences between them, suggesting that there is no need for a high tree cover to increase the CH 4 sink of the soil. This mixed tree and herbaceous cover may result in a similar environmental service output, increasing the options of land uses.
Landfills are one of the main sources of anthropogenic methane (CH4) emissions in urban areas. The environmental conditions specific to each locality, the waste management and the infrastructure of each landfill will influence the emissions of this gas. By applying different methodologies, this study aims to investigate the total contribution of CH4 to the atmosphere from a landfill, as well as the surface fluxes within the cells and the passive gas vents. According to the results, mean atmospheric CH4 concentrations from landfills were measured up to 6 ppm higher than those recorded in urban areas and locations distant from CH4 fixed sources. Two closed cells were selected to study surface fluxes by static chamber technique. CH4 uptake (1.65E-08 to 2.04E-06 g m-2 d-1) was recorded in between 60% and 87.5% of the chambers, indicating that the surface acted as a sink for the gas, as compared to the mean uptake observed from a control site (1.72E-06 g m-2 d-1). CH4 emissions from gas vents were studied using a tracer technique with permeable capsules, a methodology used for the first time in a landfill. Relatively high emissions were detected, up to 1.20E+04 g d-1. Finally, from the net CH4 emission calculated, the energy produced if the emitted CH4 were captured was estimated to be 3.23 GJ. The results highlight the importance of these studies for decision-makers to plan future landfill infrastructure adequately, implement mitigation measures to reduce emissions of this potent greenhouse gas and contribute to the energy system resources.
Having data about atmospheric concentrations in an entire urban area is difficult, hence interpolation methods are helpful. Their choice will depend on minimising the error. In this work, two deterministic (Inverse Distance Weight and Local Polynomial Interpolation) and two stochastic methods (Simple and Ordinary Kriging) were applied to predict seasonal and annual atmospheric methane (CH4) concentration means. Two sampling networks were designed in an intermediate city, covering a wide variety of urban densities, with different sampling site numbers. The main objective was to find the interpolation model that best predicts CH4 concentration and to analyse if the network's expansion improves the metric errors - the mean error (ME) and the root-mean-square error (RMSE). The ME values were close to zero in all cases, and the stochastic methods had the smallest RMSE for both networks. Besides, adding more sampling sites improved up to 50% of the RMSE values. Finally, an integrated map was obtained incorporating all the best interpolation models, which gave a difference of less than 4% between the measured and the estimated CH4 concentration. This type of study is helpful to evaluate the design of a sampling network, the territorial planning and future installations of CH4 sources.
During grazing, some of the nutrients ingested by cattle are returned to grassland as urine and dung patches and can be lost as greenhouse gases. Sites where cattle congregate are more likely to have overlapping excreta patches favouring enhanced nitrous oxide (N2O) emissions. However, there is no consensus about the magnitude of these or simultaneous methane (CH4) emissions or potential mitigation options. This study investigated the effect of combined cattle dung and urine depositions on N2O and CH4 emissions, compared with emissions from separate depositions, under different weather conditions. Local emission factors (EFs) were then calculated for both gases. A quantitative assessment of published studies was also performed to search for N2O emissions drivers. Two field experiments were performed during two 98-day trials under dry and wet conditions in Tandil, Argentina. Treatments included fresh excreta patches of urine (0.75 L), dung (2.50 kg), dung + urine (2.50 kg + 0.75 L) from Holstein dairy cows, and a control (without excreta). Soil and excreta properties were analysed, and N2O and CH4 fluxes from the patches were measured using the static chamber technique. Patches containing dung were shown to be localised CH4 hotspots. Urine applied to soil, and the addition of urine to dung patches had a negligible effect on CH4 fluxes. Urine, dung and combined patches were found to be localised N2O sources. Adding urine to dung patches under wet weather had a significant synergetic effect (threefold increase) on cumulative N2O emissions compared with the theoretical sum of separate excreta patches. Adding urine to dung patches under dry conditions gave an additive effect on N2O. These findings suggest that preventing overlapping excreta patches under wet conditions can help mitigate N2O emissions from temperate managed grazed pastures. The effect of combining excreta patches was also evident in the EF values obtained. That for CH4 was consistent with the default IPCC value (0.75 g CH4 kg⁻¹ VS), while N2O (EF = 0.03–0.39%) was lower than the updated IPCC 2019 value of 0.6%.

Lab head

M. Paula Juliarena
Department
  • Departamento de Ciencias Físicas y Ambientales
About M. Paula Juliarena
  • Maria Juliarena currently works at the Departamento de Ciencias Físicas y Ambientales, National University of the Center of the Buenos Aires Province. Maria does research in Environmental Chemistry. Their most recent publication is 'Afforested sites in a temperate grassland region: influence on soil properties and methane uptake'.

Members (9)

Sergio Alejandro Guzmán
  • National University of the Center of the Buenos Aires Province
Victoria Susana Fusé
  • National University of the Center of the Buenos Aires Province
Banira Lombardi
  • AgResearch
Maria Eugenia Priano
  • National University of the Center of the Buenos Aires Province
Carla Stadler
  • National University of the Center of the Buenos Aires Province
Ezequiel Teran
  • National University of the Center of the Buenos Aires Province
María De Bernardi
  • National University of the Center of the Buenos Aires Province
Estefania Mansilla
  • National University of the Center of the Buenos Aires Province