How does a landfill work and what happens to the waste after it is buried?

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1. 1

   Landfill (Wikipedia)

   WikipediaPublished Oct 10, 2026Checked Oct 11, 2026

   “A landfill is a site for the disposal of waste materials, including municipal solid waste. It is the oldest and most common form of waste disposal, although the systematic burial of waste with daily, intermediate, and final covers only began in the 1940s. In the past, waste was simply left in piles or thrown into pits (known in archeology as middens). Landfills take up significant amounts of land and pose environmental risks. Some landfill sites are used for waste management purposes, such as temporary storage, consolidation, and transfer, or for various stages of processing waste material, such as sorting, treatment, or recycling. Unless they are stabilized, landfills may undergo severe shaking or soil liquefaction during an earthquake. Once full, the area over a landfill site may be reclaimed for other uses. Both active and restored landfill sites can have significant environmental impacts which can persist for many years. These include the release of landfill gases that contribute to climate change and the discharge of liquid landfill leachates containing high concentrations of polluting materials.”

2. 2

   Tracking interlinked microbial and geochemical succession over decades in landfilled municipal solid waste.

   Applied and environmental microbiology (Munford et al.)Published Jul 16, 2026Checked Oct 11, 2026

   “Our work highlights the substantial changes occurring over the stabilization phase and provides a conceptual model for understanding this critical, final stage in a landfill's life cycle.IMPORTANCEAging landfills pose significant risks to environmental stability and are currently poorly modeled beyond ~20 years. Our examination of a single landfill across 39 years of waste degradation was a unique opportunity to examine the impact of time within a connected system. Our work connects geochemical data, microbial membership, and predicted function, as well as physical processes (e.g., leachate recirculation). Our conceptual model interlinks these facets across the lifespan of a landfill, providing an empirical data-based model of landfill aging. Previous models were extrapolated from younger waste and did not include the microbial dimension-a critical facet of the landfill ecosystem. Our model clarifies processes taking place in older wastes (30+ years), including oxygen infiltration, that have important implications for methane emission and metal mobility and fate over the longer term.”

3. 3

   Quantifying urban and landfill methane emissions in the United States using TROPOMI satellite data.

   Science advances (Wang et al.)Published Mar 25, 2026Checked Oct 11, 2026

   “Urban areas are major sources of population-driven methane with high potential for mitigation, but emission quantification and sectoral attribution remain uncertain. Using satellite observations and a high-resolution (12 kilometers by 12 kilometers) atmospheric inversion framework, we find that emissions from 12 major US urban areas are 80% higher than the US Environmental Protection Agency Greenhouse Gas Inventory (EPA GHGI), with up to four times higher emissions in Houston but 32 to 37% lower emissions in Los Angeles and Cincinnati. Landfills are the principal cause of inventory underestimates, with city-level management practices driving large variations in per capita emissions. Examination of individual landfills with gas collection systems shows gas collection efficiencies averaging 38% (range: 5 to 90%), much lower than their reported average of 70% (range: 40 to 87%). An exception is Los Angeles, where we find landfill gas collection averaging 85%, suggesting large urban methane mitigation potential through improved landfill management.”

4. 4

   Landfill: time capsule of plastic waste but microplastic generation source.

   Nature communications (Huang et al.)Published Aug 22, 2026Checked Oct 11, 2026

   “Landfills act as critical terrestrial sources of microplastics, functioning as "leaky time capsules" continuously releasing pollutants into surrounding ecosystems. Here, we establish a prediction model to dynamically quantify microplastic generation in landfills. By calibrating 31 years of in-situ tracking at a large-scale landfill together with a nationwide field investigation across 37 landfills, we systematically identify the spatial patterns of microplastic generation in China. East China acts as a primary hotspot contributing 45.6% of the total microplastic stock. Landfills in coastal areas account for nearly one-third of the national microplastic stock despite representing only 8.3% of the total sites. Although aggressive source reduction and in-situ remediation reduce the national microplastic by 46.4% by 2050, high-risk landfills in coastal areas remain insensitive to these measures. These findings highlight the necessity of differentiated regional control measures to effectively mitigate landfill-sourced microplastic pollution.”

5. 5

   From Waste to Health: Landfill Biogas Recovery as a Strategy for Greenhouse Gas Mitigation and Public Health Co-Benefits in Brazil.

   International journal of environmental research and public health (Nazzari et al.)Published May 13, 2026Checked Oct 11, 2026

   “Experimental analysis revealed methane concentrations from 51.10 ± 8.89% to 57.06 ± 1.19% across collection drains, indicating favorable conditions for energy utilization. Methane generation was estimated under different scenarios, reaching up to 1.30 × 104 tonnes of CH4, with peak production projected over 25-26 years depending on the model. Beyond energetic relevance, controlled biogas recovery can substantially reduce methane emissions, a key precursor of tropospheric ozone, and limit hazardous trace gas release, improving air quality and reducing population exposure to harmful pollutants. These findings are particularly relevant in developing countries, where insufficient waste management infrastructure leads to uncontrolled emissions, posing elevated environmental and health risks. This study supports integrating landfill biogas recovery into waste management and climate strategies, contributing to Sustainable Development Goals related to clean energy (SDG 7), climate action (SDG 13), and health (SDG 3), demonstrating it as a scalable solution for sustainable urban development.”

6. 6

   Biogas production and microbial profile estimation in bioreactor landfills.

   Frontiers in chemistry (Zeng et al.)Published Apr 7, 2026Checked Oct 11, 2026

   “A key observation was the absence of Nitrospirain leachate, which likely interrupts the nitrogen conversion cycle. The nitrification process was found to primarily occur in the cover layer. Decreased CH4 generation was mostly caused by ammonia inhibition, which reduced the activity of acetate-utilizing methanogenic archaea. The intermediate cover layer acted as a biochemical reaction zone with greater microbial diversity.DiscussionThe findings indicate that due to ammonia buildup, the fermentation system became unstable when the TOC/TN value fell below 13. The absence of Nitrospirain leachate is identified as a critical factor disrupting the nitrogen cycle. Therefore, inoculation with Nitrospira-containing agents is proposed as crucial for maintaining system stability and enhancing treatment efficiency. The intermediate cover layer, harboring greater microbial diversity, contributed to enhanced anaerobic digestion and supported increased system stability, functioning as a vital biochemical reaction zone. These insights provide recommendations for enhancing the AD system's CH4 production capacity.”