Bacterial Growth Graph

Bacterial Growth

Bacteria grow is liniar with the availability of food for bacteria. The grow of bacteria also depend on the availability of air, so on effluent system use aerator to make the oxygen needed for bacteria is fulfilled.

As on the graph below there is lag phase, in this phase bacteria have begun consuming food and start replicating exponentially. We can see on the graph red bacterial curve increasing and food availability decreasing in this phase.

Red Bacteria Curve

The availability of food continuous decrease and bacterial reproduction begin to slow, because more competition for food. The growth rate slowing on red bacteria curve connection with the less of food availability, bacteria begin to cluster and form floc.

The BOD indicator that bacteria food still available, higher BOD mean that food for bacteria still high. Most of bacteria have formed floc, some bacteria cells die and lyse open, releasing some BOD that can be consumed. Bacterial floc can settled out with leave a clearer effluent with little BOD behind.