Biological treatment (stabilization) typically involves which processes?

Biological treatment, also known as stabilization, fundamentally relies on the processes of aerobic or anaerobic digestion to break down organic matter present in wastewater. Aerobic digestion involves microorganisms that consume organic materials in the presence of oxygen, resulting in the conversion of these substances into carbon dioxide, water, and microbial biomass. This process not only reduces the volume of organic waste but also stabilizes the material by rendering it less harmful to the environment.

On the other hand, anaerobic digestion occurs in environments without oxygen, utilizing anaerobic bacteria to decompose organic material into biogas and digestate. This method is particularly effective for high-strength wastewater and can generate energy in the form of methane gas, making it a sustainable option for wastewater treatment.

The other processes listed, such as oxidation or reduction, filtration or sedimentation, and chlorination or dechlorination, do not encompass the primary biological actions involved in the stabilization phase of wastewater treatment. While oxidation and reduction are essential for various biochemical reactions, they are not specific to the biological treatment processes in the way that digestion is. Filtration and sedimentation pertain more to physical separation methods, and chlorination or dechlorination relates to disinfection rather than biological stabilization.