Question

Which of the following characteristics distinguishes bioreactor landfills from conventional sanitary landfills?

Dirt is placed on top of each day's waste
A layer of permeable clay or plastic is used to prevent leachate from seeping into local water supplies
Wells, vents, and flares are used to manage methane emissions
Water and air are injected through horizontal wells or trenches beneath the surface

Answer 1

Bioreactor landfills use water and air injection to enhance waste decomposition, thus managing methane efficiently and allowing for renewable energy generation from captured biogas.

Step-by-step explanation:

The characteristic that distinguishes bioreactor landfills from conventional sanitary landfills is that in bioreactor landfills, water and air are injected through horizontal wells or trenches beneath the surface. This process enhances the biodegradation of organic waste, thereby reducing the landfill mass and volume more quickly compared to traditional landfills.

By accelerating the decomposition process, bioreactor landfills can more efficiently manage methane emissions through wells, vents, and flares. The generated biogas can be captured and used as a renewable energy source, contributing to lower overall greenhouse gas emissions.

Bioreactor landfills offer cost and efficiency advantages, mostly thanks to the capabilities of certain prokaryotes that can perform bioremediation. These microorganisms break down hydrocarbons and other pollutants at the molecular level, transforming them into less harmful substances. This approach is more environmentally friendly and cost-efficient compared to conventional methods such as excavation and off-site treatment. Additionally, it reduces the risk of groundwater contamination which is a significant environmental concern in conventional landfill operations.