Determination of emission factors from a landfill through an inverse methodology: Experimental determination of ambient air concentrations and use of numerical modelling

E Gallego; J F Perales; N Aguasca; R Domínguez

doi:10.1016/j.envpol.2024.124047

Determination of emission factors from a landfill through an inverse methodology: Experimental determination of ambient air concentrations and use of numerical modelling

Environ Pollut. 2024 Apr 28:351:124047. doi: 10.1016/j.envpol.2024.124047. Online ahead of print.

Authors

E Gallego¹, J F Perales², N Aguasca³, R Domínguez³

Affiliations

¹ Laboratori Del Centre de Medi Ambient, Escola D'Enginyeria de Barcelona Est (EEBE), Universitat Politècnica de Catalunya, Av. Eduard Maristany 16, 08019, Barcelona, Spain. Electronic address: eva.gallego@upc.edu.
² Laboratori Del Centre de Medi Ambient, Escola D'Enginyeria de Barcelona Est (EEBE), Universitat Politècnica de Catalunya, Av. Eduard Maristany 16, 08019, Barcelona, Spain.
³ Prezero Gestión de Residuos, Dipòsit Controlat de Can Mata, Carretera B-231, 080781, Els Hostalets de Pierola, Spain.

PMID: 38688386
DOI: 10.1016/j.envpol.2024.124047

Abstract

The application of numeric modelling for determining the impact of landfills needs for reliable emission source data. In this study, a methodology for the characterization of the emission profiles of the different sources present in landfills for emission factors determination, applying an indirect methodology, is presented. Ambient air concentrations of volatile organic compounds (VOCs), hydrogen sulphide (H₂S) and ammonia (NH₃) were determined in three potentially emission sources in Can Mata landfill (Hostalets de Pierola, Catalonia, Spain): dumping areas, pre-closed zone and leachate reservoir as well as in biogas, for the determination of emission factors. Multi-sorbent bed and Tenax TA tubes were used for a wide range of VOCs sampling, and analysis was conducted through TD-GC/MS. H₂S and NH₃ were sampled and analysed using Radiello passive samplers. The highest total VOC (TVOC) concentrations were found in dumping areas (0.7-3.5 mg m^-3), followed by leachate reservoir (0.3-0.6 mg m^-3) and pre-closed area (77-165 μg m^-3). On the other hand, the highest H₂S and NH₃ concentrations were found in leachate reservoir, presenting values of 0.8-1.1 mg m^-3 and 1.7-1.8 mg m^-3, respectively. With the application of odour thresholds to the concentrations obtained, the most critical compounds regarding odour annoyances were determined. The highest odour units (O.U.) were found in leachate reservoir due to H₂S concentrations, whereas VOCs contributed mainly to O.U. in the dumping areas. The obtained ambient air concentrations were used for the indirect determination of the emission factors through numerical modelling using a Eulerian dispersion model. The emission factors obtained for the landfill for TVOC, H₂S and NH₃ were in the range of 0.44-10.9 g s-1, 0.16-1.02 g s^-1 and 0.23-1.82 g s^-1, respectively, depending on the emission source. Reliable emission factors are crucial to obtain landfill impact maps, which are essential for the correct management of these facilities.

Keywords: Ammonia; Hydrogen sulphide; Indirect emission factors measurement; Landfill emission; TD-GC/MS; Volatile organic compounds (VOCs).