Biological treatment

Biological treatment is a process applied to wastewater (industrial and/or domestic), utilizing microorganisms, typically bacteria in flake form. This biomass utilizes biodegradable organic substances present in the wastewater for nourishment, reproduction, and to degrade contaminants into smaller compounds.

What is meant by treatment?

Treatment refers to a series of processes and procedures used to purify water, ensuring its safety for environmental and industrial consumption. Through biological water treatment, pollutants, microbes, and other impurities are removed, making the water suitable for safe discharge into the environment.

What does it mean that bacteria have a “form of flakes”?

Microorganisms for biological water treatment agglomerate around suspended organic matter, forming flake-like masses as they feed. These flocs, visible to the naked eye, tend to sediment under calm conditions and can be easily separated from the purified water that remains on the surface (supernatant).

How does water treatment with activated sludge work?

Biological treatment with activated sludge occurs in tanks that simulate the natural biological mechanisms responsible for purifying water polluted by biodegradable organic substances. When an effluent is mixed with activated sludge containing a high bacterial load, it undergoes a process similar to self-purification in nature, but in a faster and more space-efficient manner.

One advantage of using activated sludge over natural purification is that the microbial flora employed in wastewater treatment tends to aggregate into flakes (organic matter and bacteria) rather than remaining dispersed in the treated effluent. These flakes settle under calm conditions, allowing easy separation from the purified water that remains on the surface (supernatant).

How is organic matter treated?

Organic matter in wastewater undergoes partial mineralization, producing gaseous by-products such as CO2, H2O, and energy that are environmentally harmless. The highly putrescible portion requires additional processing before disposal, constituting the sludge line in purification plants. Oxygen is crucial for these reactions, enabling bacteria to respire, grow, and reproduce.

The most effective way to introduce oxygen into oxidation tanks is through a micro-bubble air diffusion system, as it ensures a better and more uniform distribution of oxygen throughout the entire volume of the basin.