Waste water, as a result of its various components, needs to be treated to become fresh water again. This treatment is performed in a series of certain processes, the central steps of which make use of hungry micro-organisms. So what does a treatment plant look like?
Set-up of a Waste Water Treatment Plant
Everybody has probably seen a waste water treatment plant. They are usually composed of several basins, round or rectangular in shape, of sizes not less than some 100 square metres.
Rake with sand and grease trap - this is, of course, the waste water itself, and where it first runs into the treatment plant.
Primary clarification tank - this area is for the initial sedimentation and decanting of the waste water. Also, the first biological degradation processes may take place.
Sludge - this is very important for biological treatment. Firstly, it fixes micro-organisms in one place. Secondly, it degrades like compost when the biomass has died.
Service building - this is the place where treatment plant personnel contribute to the waste water1 and its treatment (documentation, process-monitoring, etc).
Secondary settling tank - in the final step of the waste water treatment the aim is to let all the sediments sink down so that clean water can be decanted from the top.