What type of decomposition occurs in an established sanitary landfill?

In an established sanitary landfill, anaerobic decomposition is the primary type of decomposition that occurs. This process takes place in environments where oxygen is limited or absent, which is typical in the dense layers of waste buried in a landfill.

During anaerobic decomposition, microorganisms break down organic materials in the absence of oxygen, resulting in the production of methane and carbon dioxide as byproducts. This process is vital in landfills because it helps reduce the volume of waste over time and contributes to the generation of biogas, which can potentially be harnessed for energy.

The anaerobic environment is created by the compacted layers of refuse, which prevents significant air exchange. Over time, as organic matter breaks down, the conditions in the landfill may shift, allowing some limited aerobic processes to occur in the upper layers where oxygen might be present. However, the predominant decomposition mechanism deep within an established landfill remains anaerobic due to the significant compaction and lack of air circulation.

Understanding the difference between anaerobic and other types of decomposition is essential for managing landfills effectively, especially in terms of gas collection systems and the evaluation of leachate impacts on the environment.