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Wastewater Treatment

Wastewater Treatment


In this article, we talk about a small introduction of wastewater treatment which is a very interesting field in engineering.
Wastewater treatment, also called sewage treatment, is the removal of impurities from contaminant waters before they reach aquifers, lakes, rivers, estuaries, and oceans. The principal difference from drinking water treatment is the pollution provide by human activity and this kind of treatment is the element of pollution control.




The treatment considers various types of wastewater problems and the selection of the proper mode of treatment, as well as the design of the equipment required and that make the application of physical, biological and chemical process who is a divide in these phases:


Preliminary treatment


The first processes that the wastewater encounters, which typically involves flow measurement where can quantify how much wastewater is being treated. Flow monitoring is commonly followed by screenings removal. Screenings are a string like materials and large foreign objects for example; sticks, an errant golf ball or any large material.




These materials got to be removed as a result of they’ll damage machinery or clog processes.


Primary treatment


It is a physical settling process that removes solids. Wastewater that enters the first subsidence tank (or clarifier) is delayed to alter the heavier solids to settle to the bottom.


Lighter materials, such as grease, will float to the top of the tank.


Settling tanks are designed with mechanisms to remove both the settled solids, as well as the floating solids.


Secondary treatment




It is a biological treatment process used to stabilize the dissolved solids (the heart of process). Microorganisms (e.g., bacteria) feed on the organic solids and convert the organics into a cellular or biological mass that can later be removed. These biological processes are aerobic processes (also there anaerobic process).


Oxygen should be provided for these aerobic organisms to figure properly and expeditiously.


An integral part of secondary treatment processes is another set of subsidence tanks or clarifiers.


These secondary clarifiers (final clarifiers) take away the biological mass that has grown during biological treatment.

Tertiary Treatment




This step is called disinfection. Disinfection means the inactivation of disease-causing organisms (pathogens).


It is typically confused with sterilization which means the killing of all organisms.

Treatment Sludge


Solids what pumped out in the primary and secondary clarifiers are referred to as sludge. Sludge from biological treatment processes is referred to as biosolids. Sludge is the byproduct of treating liquid wastewater. Excess solids can also lead to a sanitary problem to the plant and community if it is not treated.




Local conditions typically dictate that choice is best for your specific facility.


We have in the next image an example of wastewater treatment plant:


Waste Water Treatment
Waste Water Treatment


In the next article, we will talk with more details about the steps and technologies what exist this day!


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