Why is domestic wastewater treatment important?
Characteristics of domestic wastewater
Domestic wastewater often contains many
impurities. The main part, namely 52% is composed of organic content and
inorganic substances account for the remaining 48%. Moreover, there are a large
number of viruses and disease-causing bacteria. Besides, there are also
types of bacteria that are not harmful but on the contrary help to decompose
some types of waste.
Why is wastewater treatment important?
- Domestic
wastewater inherently contains many impurities as well as environmental
pollutants, specifically chemicals and microorganisms. If wastewater is
not treated properly, it can lead to problems such as clogged pipes, cloudy
water, and ecological imbalance, thereby causing environmental pollution, soil,
water and air pollution.
- If
not treated, domestic wastewater also contains many types of bacteria and
viruses that cause many dangerous diseases such as diarrhea, malaria,
water-borne diseases, etc. Besides, chemical compounds found in wastewater also
greatly affect human health if a direct exposure for a longer time.
- When
wastewater treatment is not carried out properly, domestic wastewater can lead
to clogged pipes and therefore cause damages to facilities and water treatment
systems. This can have some effects on human health and seriously affect both
water and soil environments.
- Domestic
wastewater can also cause specific problems such as reducing the oxygen
concentration in water, thereby posing a serious threat to the life of animals
and plants.
How does the domestic wastewater treatment process work ?
- Domestic
wastewater is water discharged after people use it to serve daily activities
such as cooking, washing, bathing or water discharged from shopping centres,
entertainment areas, restaurants, cafes, etc.
- Domestic wastewater treatment is
an activity to remove impurities from daily wastewater to create a suitable
type of wastewater without polluting or affecting the surrounding
environment. From there, water pollution can be prevented from untreated
wastewater discharged directly into the environment.
Domestic wastewater treatment process:
Domestic wastewater treatment using AAO technology.
· Step
1: Usually, large-sized trash will be removed through the trash screen, then
oil and grease will be separated and pre-treated before that the wastewater is
sent into the centralized tank. This process will partly help to increase
the lifespan and performance of the wastewater treatment system.
· Step
2: The wastewater is sent directly from the collection tank to the
equalization tank. The latter neutralizes the concentration and flow of
wastewater to conduct domestic wastewater treatment. The equalization tank
will receive water brought from the collection tank and then continuously
aerate so that the wastewater treatment process is not overloaded and reduces
the size of wastewater treatment works.
· Step
3: In the anoxic tank, the nitrification and decomposition of other
organic substances takes place, and the BOD content decreases. The wastewater
will be treated with the support of anoxic microorganisms that perform phosphorus
reduction, then continue to participate in the process of synthesizing and
storing energy in microbial cells.
· Step
4: Microorganisms directly adhere to the substrate through consecutive
motion processes, so the decomposition time of organic compounds will take
place faster. Therefore, organisms are considered to play a very important
role in the wastewater treatment process. During the entire process, it
must be ensured that the BOD content doesn’t exceed the threshold of 5mg/litre.
· Step
5: The residue is settled in the sedimentation tank, the biological sludge
will be retained, and the settled sludge will be pumped to the aerobic tank to maintain
the concentration of microorganisms. The rest will be returned to the tank for sludge
storage for treatment. After being treated, the water will be pumped
through the intermediate tank.
· Step
6: The pressure filter tank is a place for sediment deposition and removal
of suspended particles in the water source. Afterwards, the wastewater continues
to be treated to reach the prescribed standards.
· Step
7: The domestic water, after going through the above treatment process,
will be disinfected before being used directly. Waste sludge participates
in the process of compressing and pressing sludge to separate the water and the
sediments. The water sludge will be pumped to the collection pit, while
the remaining sludge will be used for other purposes.
There have been many cases of diseases spread
through the water environment that are dangerous to human health such as
typhoid, cholera, polio, hepatitis, etc. Therefore, properly treating
domestic wastewater has a great impact on the population’s health. Domestic
wastewater treatment technology is important in the process of removing
pollutants. Hopefully, the FEC's shared article will help you in the
process of finding ways to treat domestic wastewater.