Environment-Economic-Energy (3e) Analysis of Municipal Solid Waste Landfill Mining: A Case Study in China

Landfill mining (LFM), which refers to the excavation, processing, treatment and recycling of formerly buried waste, is widely regarded as an effective strategy for the management of landfills. It may offer environmental, economic, and energy potential benefits through the mitigation of greenhouse gas emissions and the recovery of dormant materials, land resources, and energy carriers. Thus, carrying out an environment-economic-energy (3E) assessment of LFM is essential. However, LFM projects assessed from 3E perspectives are hardly documented. This work focuses on the 3E analysis model for assessing the feasibility of LFM which compared two scenarios of mining and non-mining. It innovatively combines the principles of 3E assessment and Monte Carlo Simulation in an effort to understand how different waste compositions affect potential outcomes of 3E aspects and their interrelationships. And this conbined method was first applied on case study of a typical MSW LFM project in China (Baotian landfill). It was found that the average equivalent CO2 emissions and leachate yield from LFM were 162.78 kgCO2·t-1 and 0.04 m3·t-1, respectively, which were considerably lower than the 513.50 kgCO2·t-1 and 1.13 m3·t-1 if the landfill was to be maintained for 30 years after closure. Moreover, the average profit of LFM project was 8.34 USD·t-1 compared to -2.80 USD·t-1 without excavation. Lastly, the average energy recovery through LFM was 143.62 kWh·t-1, while no energy was recovered in the non-mining scenario. The results suggest that LFM is more sustainable for waste management than non-mining. The sensitivity analyses indicate a tight interconnection among 3E aspects.