How to reduce odorous and greenhouse gas emissions in landfills

The so-called “bad smell” of the landfill comes from leachates but above all from biogases generated by the natural processes of degradation and decomposition of waste.

The decomposition of waste in landfill occurs through different processes that present various and complex aspects on which we will not dwell. Let us just remember that the technical literature reports an interesting factor, namely that the biogasification process in landfill, once started, is demonstrated for several years: over 30.

In fact, there are various types of “biogas” because the components that constitute it have variable volumetric incidences.

The main macrocomponents of biogas are methane (CH4) and carbon dioxide (CO2), both important greenhouse gases that contribute to the intensification of the greenhouse effect.

In particular, the emission of methane CH4 into the atmosphere is characterized by a Global Warming Potential (GWP) equal to:

as reported in the sixth and final IPPC assessment report published on 9 August 2021 and called AR6.

Then there are a certain number of microcomponents (H₂O, H₂S, NH₂, CO₂, etc.) which, although with a lower incidence, give biogas peculiar characteristics such as odor. So, what are the odorous microcomponents of biogas?

This depends on many concomitant factors that contribute to the degradation and decomposition of waste (for example, the chemical and commodity composition of the waste, the arrangement and adjacency, as well as the anisotropy of the discharge, the temperature, the presence or absence of oxygen and humidity, pressure, etc.). Among the most relevant odorous microcomponents are:

Unpleasant odor emissions from landfill waste management activities represent a difficult situation that involves many people and has a significant impact on the quality of life of those exposed to it. The assessment of the legitimacy of odor emissions is an extremely complex factor that involves tolerability criteria and subjective sensation/perception of bad odor, as well as health, safety and environmental protection criteria.

In recent years, some solutions have been developed and adopted to significantly improve the collection efficiency of traditional systems usually used in landfills and among these solutions we highlight GAS STABILIZER, an innovative system patented at international level that acts as the mind/brain of the entire collection system present in the landfill.

GAS STABILIZER is the innovative technology of ZERO3 that realizes the automation of landfill biogas collection in response to the indications of the UNI/TR 11917:2023 standard.

Landfills that have installed GAS STABILIZER have achieved excellent results both in terms of increased volumes of biogas captured and in terms of reduction of odors and greenhouse gas emissions.

GAS STABILIZER can be installed throughout the landfill, even near the waste discharge front, where odorous emissions begin to be significant.

Compared to traditional systems, it is positioned between the manual regulation stations (element 3) and the secondary biogas transport lines (element 4) and can be applied both in new capture plants and in existing plants.