Sewage water is liquid waste resulting from different human activities, industrial, household, commercial, or institutional; it is collected through a network of interconnected channels to reach a specific collection point to start the treatment process, and this point is called a station water treatment.
They are facilities and centers of great environmental importance and huge material cost when it comes to construction, operation and maintenance. The types of treatment plants vary depending on the type of water to be treated, the size of these facilities, and then the purpose of their construction, which is related to the type of water produced after the treatment process.
Why is wastewater treated?
The scarcity of water, the increase in population, the industrial progress, and the increase in welfare in most parts of the world have led to a significant increase in the quantities of sanitation, which led to the search for means aimed at treating the wastewater and then re-used for the purposes of agriculture and refrigeration in factories.
Stages of wastewater treatment
Treatment plants and wastewater are subjected to a set of different stages in which this water is filtered and sterilized to be suitable for reuse, we summarize these stages as follows:
First: Primary treatment / physical therapy
The separation of inorganic supernatants such as wood and plastic parts is carried out by means of barrier windows, then the sand is removed and the suspended materials on the surface of the water, including fats, are removed.
Second: Secondary treatment / biological treatment
It is the primary stage in the treatment process, in which the appropriate climate is provided by ventilation, in order to convert the wastes from organic materials into inorganic materials (gases and cellular tissues) heavier than water, to precipitate in the bottom and easy to exclude.
Third: triple therapy
Its purpose is to achieve the following two things:
1- Removing fine, hard and fine suspended matter, and reducing BOD in final treated water.
2- Reducing the concentrations of pathogens such as bacteria, eggs, worms and other delicate insects, and adding chlorine for sterilization and disinfection, so that any element that is harmful to public health is avoided.
Treatment plant components
Wastewater passes during its treatment in treatment plants, with several facilities, which are the most prominent pillars of these centers, which are:
The suspended or floating oversized materials are insulated on the surface of the water, which are channels with windows and manual and mechanical filters.
2. Sand removal basins
It is deposited with sand and suspended inorganic materials, and it consists of channels with a space to collect sand.
3. Primary sedimentation basins
The largest amount of organic and inorganic substances are deposited, and floatable substances are disposed of.
4. Ventilation tanks
The stage of biological treatment and the purpose of this stage is to convert the organic substances dissolved in water into suspended solids that can be deposited by activating the air bacteria and microorganisms.
5. Final sedimentation basins
The suspended solids from the ventilation stage are deposited.
6. Tubs in contact with chlorine
In it, pure chlorine is added to the wastewater, to get rid of bacteria and microorganisms in the treated water, after the water has passed from the final sedimentation basins.