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Titel |
\section{Airborne monitoring of landfills CH4 emissions} |
VerfasserIn |
Daniele Gasbarra, Beniamino Gioli, Pantaleone Carlucci, Vincenzo Magliulo, Piero Toscano, Alessandro Zaldei |
Konferenz |
EGU General Assembly 2017
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Medientyp |
Artikel
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Sprache |
en
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 19 (2017) |
Datensatznummer |
250150302
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Publikation (Nr.) |
EGU/EGU2017-14745.pdf |
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Zusammenfassung |
The disposal and treatment of waste produces emissions of greenhouse gases (GHGs), which
contribute to global climate change. In particular, large quantities of Methane are released in
the breakdown of organic matter in landfills.
In this work we present a new payload of the Sky Arrow ERA aircraft and an original
methodology to compute methane emissions, based on the atmospheric mass budget
approach. The payload is presently being used for intensive measurements in the area known
as “Terra dei fuochi”. In this area, located between the provinces of Naples and Caserta
(Southern Italy), urban waste combined with industrial toxic waste has been illegally dumped
in old quarries or buried in the nearby countryside for decades. This led to patchy
sources of methane, with several hot spots spread over a heterogeneous land. In this
context, the use of aircraft allows for the investigation at the landscape as well
as at the regional scale, taking into account all sources, including those of small
dimensions.
The Sky Arrow ERA is equipped with the Mobile Flux Platform, capable of deriving the
3D wind vector at 50 Hz, while CO2 and water vapor densities are measured by an infrared
gas analyzer (Licor 7500).
A new configuration of the Licor 7700 open path fast methane gas analyzer was
developed, based on enclosing the sensor within a cylinder exposed to the external air in-flow.
This set-up allows for fast response measurements, while avoiding external modifications,
subjected to restrictions.
Ambient methane mixing ratios in excess of 7 ppm were measured during landfills
overpasses; performing grid flight plans at different heights, to describe a virtual box
enclosing the study area, and applying interpolation procedures, it was possible to reconstruct
wind components and scalar concentrations in a 5x5 kilometers domain containing 6 different
landfills, with a resolution of 50 m horizontal and 20 m vertical.
For each flight the methane mass flows along and across the wind direction have been
computed as products of gas densities and wind speed, while contributions of each individual
landfill to total flows were computed with a GLM (general linear model) approach. More than
15 flights were performed from October 2015 to December 2016. Results revealed high
methane emissions ranging from 150 g s−1 to 400 g s−1for the entire domain with a mean
value of 240 g s−1; no seasonal variation was observed over the whole measuring period. |
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