Introduction of Microorganisms
The biological portion of the treatment system is commonly referred to as secondary treatment. This involves the removal of suspended solids and oxygen-demanding constituents from the wastewater. This is done by introducing the wastewater into a system of highly concentrated microorganisms (such as bacteria, nematodes, protozoans, etc.), which will consume the solids and oxygen-demanding constituents as food. This process is accomplished by pumping the water from the primary clarification process over the bio-tower. The bio-tower is full of plastic media that has a growth of biological film on it.