CO₂ emissions from a municipal site for final disposal of solid waste in Gualeguaychu, Entre Rios Province, Argentina

This paper estimates CO₂ fluxes in a municipal site for final disposal of solid waste, located in Gualeguaychu, Argentina. Estimations were made using the accumulation chamber methods, which had been calibrated previously in laboratory. CO₂ fluxes ranged from 31 to 331 g m⁻² day⁻¹. Three different populations were identified: background soil gases averaging 46 g m⁻² day⁻¹, intermediate anomalous values averaging 110 g m⁻² day⁻¹ and high anomalous values averaging 270 g m⁻² day⁻¹. Gas samples to a depth of 20 cm were also taken. Gas fractions, XCO₂ < 0.1, XCH₄ < 0.01, XN₂ ~0.71 and XO₂ ~0.21, δ¹³C of CO₂ (−34 to −18‰), as well as age of waste emplacement, suggest that the study site may be at the final stage of aerobic biodegradation. In a first approach, and following the downstream direction of groundwater flow, alkalinity and δ¹³C of dissolved inorganic carbon (−15 to 4‰) were observed to increase when groundwater passed through the disposal site. This suggests that the CO₂ generated by waste biodegradation dissolves or that dissolved organic matter appears as a result of leachate degradation.