Evaluating the physicochemical properties of refuse with a short-term landfill age and odorous pollutants emission during landfill mining: A case study

A field excavation of refuse with a short-term landfill age from the Qingdao Xiaojianxi municipal solid waste (MSW) landfill was conducted. The physical composition and chemical properties of refuse with landfill ages of 1-4 years were studied, and the emission characteristics of odorous pollutants during the excavation period were monitored. The refuse aged 1-2 years has a higher proportion of combustible material than that the refuse aged 3-4 years, and the volatile content and calorific value in refuse aged 1-2 years were also higher than those in refuse aged 3-4 years, indicating that the refuse with a short-term landfill age was more suitable for incineration than refuse with a long-term landfill age. The pH and available phosphorus (AP) gradually increased with increasing landfill age, while the total Kjeldahl nitrogen (TKN) and organic matter (OM) decreased. The contents of the heavy metals Cu, Zn, Ni, Pb and As generally decreased with landfill age, especially in refuse aged 2-4 years, whereas the Cr content showed no significant differences in refuse aged 1-4 years. The main odorous pollutants emitted during the excavation and screening periods were ammonia (NH3) and carbon disulfide (CS2), and the odor intensity of excavated refuse aged 1-3 years was higher than that of refuse aged 4 years. Under the condition of a small excavation area and continuous deodorization, the pollution intensity can meet the discharge standards of the factory boundary. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

The study found that the chemical properties and physical composition of refuse change with the landfill age, and fresh refuse is more suitable for incineration treatment; the emissions of ammonia and carbon disulfide from 1-2 year-old refuse with high volatile content and calorific value were more significant. Under the conditions of small-scale cleaning and continuous reduction of odor emissions, the pollution intensity can meet the emission standards.