What happens during the decomposition stage of self-purification?

During the decomposition stage of self-purification, oxygen depletion occurs, leading to the dominance of anaerobic bacteria. This process is a critical part of how water bodies respond to pollution. Anaerobic bacteria do not require oxygen to survive and are able to break down organic matter in environments where oxygen levels are low.

As they metabolize, these bacteria contribute to the breakdown of pollutants, such as organic waste, in the water. However, the absence of aerobic processes during this stage means that oxygen levels in the water decrease significantly, which can lead to further consequences for aquatic life.

In contrast, aerobic bacteria, which function best in oxygen-rich environments, are more involved in the earlier stages of decomposition. They help in breaking down organic materials more efficiently and promote a healthier ecosystem by maintaining oxygen levels.

The idea that pollution is completely removed or that water becomes clean is inaccurate because, during this stage, while some degradation of pollutants occurs, the process can also produce byproducts that may not be beneficial, and the presence of anaerobic conditions can lead to unpleasant odors and other issues.

Thus, the scenario of oxygen depletion and the prevalence of anaerobic bacteria acting as decomposers is a fundamental aspect of understanding the self-purification process in