What is anaerobic digestion?

Anaerobic digestion is a biochemical process where microorganisms decompose organic matter in the absence of oxygen. This method is particularly important in wastewater treatment as it helps in reducing the volume of organic materials, simultaneously generating biogas that can be utilized as a renewable energy source. During this process, the microorganisms feed on the organic matter, producing methane, carbon dioxide, and other gases, along with nutrient-rich digestate, which can be used as fertilizer.

The other options do not align with the concept of anaerobic digestion. Exposing wastewater to air, for example, would typically involve aerobic processes, where oxygen is present for microorganisms to break down organic materials. Chemical treatments involving chlorine focus on disinfection rather than biological breakdown, and filtering techniques aim to remove physical debris rather than process organic matter anaerobically. Consequently, the selection of the correct answer reflects an understanding of how anaerobic digestion specifically utilizes microorganisms in an oxygen-free environment to manage organic waste effectively.