Microorganisms are essential to the treatment process.
However you need to control their growth as beyond a certain number, microorganisms can actually hinder treatment.
In this article, I show you how you can estimate the ideal number of bacteria you need to insure effective treatment.
Exponential Growth Of Microorganism: There are several single celled microorganisms found in water.
Upon attaining an appropriate size, these cells divide.
This stage is reached when there is plenty of food for these microorganisms in wastewater.
When a large number of such cellular microorganisms begin to divide and increase there number in wastewater, then we say that they have reached an exponential phase in their growth rate.
This phase though cannot be sustained for long as the food for the microorganisms, like proteins and other dissolved substances, are fast depleted due to consumption by these microorganisms in wastewater.
This phase can also be tested in laboratories to understand the way they grow, the type and quantity of food they seek and consume in wastewater and the conditions they use to reach the exponential rate of growth.
Food-To-Microorganism Ratio: This ratio is used to measure the amount of food (in pounds) being fed into the treatment plant by the incoming wastewater to the actual quantity of microorganisms present in the wastewater.
This ratio is of great importance in the activated sludge reduction process.
This process is usually implemented with a F/M ratio kept in the range 0.
2 to 0.
6 mg of biochemical oxygen demand.
Operating in this range causes the filamentous bacteria (especially the Nocardia species) to multiply rapidly which creates foam.
This range also highlights the importance of microorganisms in wastewater treatment.
Hence it can be said that the ratio helps in determining the right quantity of these microorganisms required for the treatment process.