English (United States)
The sanitary sewerage system collects and treats waste water from the community to return it to the environment.
The water that reaches our homes from the aqueduct system is drinking water. It is us, the users, who contaminate it through our use of it. We use water in industry, commerce, agriculture, for public purposes, and in our homes. This water that comes through the drain transporting waste to the sanitary sewer network, is called waste water. Finally, sewer pipes lead them to a treatment plant. However, waste water can go to a septic tank in some locations.
A septic tank is a tank in a house, school or building that temporarily stores this water until a specialized truck collects it at the request of the owner of the place. They are then transported to the nearest sewer plant. These wells are gradually being replaced by the sewer pipe. The goal is to connect the entire population.
Waste water is composed of a liquid part and solid part (organic and inorganic), gases (such as oxygen and hydrogen sulfide), and living microorganisms. These components affect their purity and quality.
This is why a large part of the process of water treatment involves removing as much of these impurities as possible. The result is to produce clean water that returns to nature, in rivers and oceans, preserving the health of human beings and the environment. In turn, the recovered solids, after being stabilized, serve as fertilizer or landfill.
The process of treating waste water in a sanitary sewage plant: The plant is a facility that receives used water from the community (discharged) through drains and sewer pipe networks.
The six water treatment steps are as follows:
Affluent collection*: It is the arrival of waste water from the community to the treatment plant. In the pipeline network there are pump stations, to propel water along its route.
Removal of large and sandy solids: The tributary faces a grill, a desander, and some grinders that remove large solids such as garbage and sandstone, which, because it is abrasive, damages treatment equipment.
Treatment: Depending on the type of treatment plant, it can be of three types.
Physical or primary treatment: separates solids from water by sedimentation through gravity. In this process, the solids settle at the bottom of a clarifying or sedimentating tank, obtaining clear water in the upper part.
Biological or secondary treatment: removes and chemically transforms those solids that have not settled and remain dissolved in water through biodegradation. It converts them into simple, non-degradable substances that do not produce a bad smell.
Advanced or tertiary treatment: It is a sophisticated and expensive method that removes substances such as nitrites and nitrates. These nitrogen compounds must be removed in special cases as established by the plant's discharge permit. Therefore, its implementation is not a general requirement in all treatments.
Disinfection: Clear water is disinfected with chlorine, making it compatible with water in rivers and oceans.
Effluent discharge**: Disinfected water is reoxygenated to preserve aquatic life, its quality and is reincorporated into the environment. The effluent is the treated water produced by the plant and which quality parameters are stipulated in a document (Discharge Permit) granted by the Federal Environmental Protection Agency (EPA) and the Environmental Quality Board (JCA).
Sludge stabilization: The recovered solids are called sludge or silt. They are stabilized by biodegradation with bacteria that, by converting them into inert and simple matter, lose their bad smell and dangerousness. They are also dried in the sun or with machines to reduce their volume and serve as fertilizer (compost or manure) or filler for landfills.
