Traitement microbien des eaux usées

When domestic or industrial effluents enter natural waters, microbial communities drive the breakdown and removal of contaminants.

In oxygen-rich surface layers, aerobic heterotrophs rapidly oxidize organic matter into carbon dioxide and biomass.

As oxygen concentration decreases in deeper sediments or stagnant zones, anaerobic microbes take over, continuing degradation through processes like fermentation, sulphate reduction, or methanogenesis.

Nutrient pollution, particularly from nitrogen and phosphorus, is a major driver of eutrophication.

It triggers algal blooms, which consume available oxygen, creating hypoxic zones that kill aquatic life.

Aerobic and anaerobic microbes incorporate these nutrients into biomass.

This storage is temporary, as the nutrients are remobilized into the water during microbial decay.

In wetlands, microbial biofilms on roots act as filters, capturing and transforming pollutants as water flows through the root zone.

Natural microbial processes protect ecosystem health, but their buffering capacity is limited. So, engineered wastewater treatment plants help manage the continuous inflow of nutrients and toxins.