Hello, community. How are you? I hope you're having a great Monday....
Today I will talk to you about this topic that we are currently seeing in the university, and it has seemed to me a very important topic because thanks to the implementation of certain structures and techniques it has been avoided to pollute the rivers and seas of the planet, but first of all...
What is wastewater?
Basically, these are the waters that have already been used to fulfill a certain function both in the home (domestic) and in industry. For example:
- Domestic: Water from the kitchen, bathrooms (toilet, sink and showers), etc.
- Industries: Water that is contaminated with chemicals such as lead, copper, etc.
All this wastewater is discharged into the sewage system. The sewerage system is the set of pipes that are responsible for receiving, directing and evacuating them. In the past, all this polluted water was dumped into the rivers and seas of the cities, causing a great negative impact on the fauna and flora that live in these habitats, but fortunately, structures have been created to improve the quality of the water and are called...
Wastewater treatment plants (WWTP)
It is here that, thanks to the use of a series of physical, chemical and biological processes, a large number of pollutants dangerous to human health and the environment are eliminated.
But..
What are the processes used?
According to the amount of contamination and the use that the water will have after being treated, so will be the number of processes that are carried out. Let's see the following image that shows us the vast majority of these...
Source
As the first element belonging to the treatment plant we have.
Screening or sieving
The screening system is a set of grids or sieves that have the function of preventing the entry of large materials such as diapers, tires, branches etc. to the following elements that make up the plant because they could damage them.
Degreaser tank
This structure is in charge of eliminating grease, foam and floating elements that are in the water, this is achieved thanks to the different densities of the materials (grease, water, solid elements).
As the mixture enters the tank, the grease will remain at the top, the water will remain at the bottom of the tank and the solids will remain at the bottom of the tank and as you can see in the middle of the tank is located a pipe and it is through this where the water enters the next tank free of grease and floating elements.
Grit tank
As the name xD indicates, this structure is responsible for removing gravel, stones and heavy elements that have passed through the screening system, thus avoiding clogging in the other structures.
Decanter or primary settler
The sedimentation process is similar to that of a grit trap, where the differences are that the water flows more slowly in the grit trap and that much smaller particles are removed here, and that due to their insignificant weight they are not able to settle in the grit trap. These particles are called (colloids).
To help sediment these particles, chemical substances or coagulants (alumina sulphate) are used to remove an electrical layer that covers the colloids and thus prevents them from repelling each other and thanks to the movement generated by the rotational system that has the settler, they are able to join together and gain weight and consequently end up at the bottom of the tank.
Post in Spanish. ¿Cómo se mejora la calidad del agua residual? #1.
Source of information
Source of information
Libro. Design elements for aqueduct and sewerage. Ricardo Alfredo López Cualla.
Well guys this is it for today, tomorrow we will continue with the second part of the processes that are carried out in a treatment plant to improve the quality of the wastewater.