Around 80% of the water used in India flows back into nature.
If left untreated, this water can prove to be a serious hazard to health and the environment.
Untreated sewage water affects human health as well as human livelihood when it enters freshwater bodies.
Wastewater treatment has health, environmental, as well as economic benefits.
- Preservation of the environment
- Savings in terms of costs and water
- Improved quality of life
Explore the detailed benefits of sewage water treatment plants on our blog here.
Consumption of this contaminated water causes several diseases, and its touch can cause skin disorders. Untreated sewage depletes the oxygen levels in the water, making sustenance of aquatic life difficult.
The sewerage system in modern cities and towns feeds water to a sewage water treatment plant where it is cleaned and made safe for release in water bodies.
Suitable sewage water treatment plants deployed at industrial as well as residential facilities can remove 90%-99% impurities from wastewater.
Consumption of this contaminated water causes several diseases, and its touch can cause skin disorders. Untreated sewage depletes the oxygen levels in the water, making sustenance of aquatic life difficult.
The sewerage system in modern cities and towns feeds water to a sewerage treatment plant where it is cleaned and made safe for release in water bodies.
Suitable water treatment plant deployed at industrial as well as residential facilities can remove 90%-99% impurities from waste water.
Wastewater treatment has health, environmental, as well as economic benefits.
- Preservation of the environment
- Savings in terms of costs and water
- Improved quality of life
Explore the detailed benefits of sewage water treatment plants on our blog here.
How a sewage treatment plant works?
The wastewater treatment process removes the physical, chemical as well as biological contaminants in water to make it safe for release in the environment. In order to be cleaned, the water must pass through several stages of filtration in the sewage water treatment plant.
Vertical bars
In the pre-treatment process, the sewage water is put through grids or vertical bars that can remove large solid substances such as plastic, metal cans, and paper. Bar screens used in the water treatment process are typically mechanically raked at certain intervals depending upon the flow rate of the water treatment plant. The waste recovered at this stage is sent of to solid waste treatment facilities.
Grit chamber
After this, the sewage flows at a very slow pace through a grit chamber. As the sewage flows into the grit chamber of the sewage treatment plant, the velocity of the rather viscous sewage is adjusted to allow particles such as pebbles, soil and sand to settle down. Three types of grit chambers are used in the sewage water treatment process.
- Horizontal grit chambers
- Aerated grit chambers
- Vortex grit chambers
Settling tank
After going through the pre-treatment process in vertical bars and grit chambers in the sewage treatment plant, the sewage flows into a settling tank, also known as a primary clarifier. In this stage of the water treatment process, the solid waste like feces settles down into the chamber while the rest of the water flows onto the next tank. For wastewater being pumped into clarifiers, it is important that the flow rate of the water being pumped in should not exceed the settling velocity of the particles to be removed. In order to ensure this, the size and number of the primary clarifier is varied in accordance with the plant’s permitted sewage flow rate.
While the solid waste (called sludge) settles down at the bottom, materials such as oil, soap etc (called scum) rise to the top. The scum is removed using a skimmer, and sludge is removed with a scrapper at regular intervals. The water that is left now is called clarified water.
Aeration basin
From the settling tank, the water flows over a weir wall and into the aeration tank. In this part of the water treatment process, the sewage is cleaned of most biological waste. At the bottom of the aeration basin in the STP, there are hundreds of tiny air blowers which blow air and create bubbles in the water. This helps the aerobic bacteria in the mixture to grow and feed upon the organic contaminants. This introduction of a significant amount of bacteria along with large amount of oxygen injected through the air blowers creates an environment suited for aerobic digestion. Aerobic digestion is the process of breakdown of organic matter along with excess oxygen.
In many older water treatment plants, the bio-filtration process is conducted before the sewage flows into the aeration basin. In this stage of the wastewater treatment process, bio-filters or trickling filters will trickle the effluent over a medium such as stone or plastic and allow a film of bacteria to decompose any organic matter. Newer sewage water treatment plants with more efficient processes do not require this step.
Clarifier
The remaining compound is then pumped into a secondary filter called a clarifier. In this chamber, the activated sludge settles out by gravity. This is the final step of the wastewater treatment process to remove solids and larger biological matter from the sewage water. The activated sludge in clarifier and the sludge produced in the primary process is sent into a digester within the sewage treatment plant. Here, it is decomposed by anaerobic bacteria, producing biogas.
At this point, 85% of all organic matter is removed from the water.
The activated sludge is then let into sand drying beds. Some water from the activated sludge evaporates while the rest is drained through the sand beds. The dried sludge that remains here can be used for making fertilizers or compost.
Disinfectant chamber
Disinfection is the final step of wastewater treatment process. The water in the disinfection chamber of the STP is treated with agents such as chlorine, ozone, or ultraviolet disinfection process. This process removes the phosphorous and nitrogen compounds as well as bacteria from the water. When chlorine is added to the water in the disinfection chamber, it must be removed before discharging the water so as not to harm marine life.
Water is generally discharged in a water body after the due water treatment process. However, in areas where water is scarce, it is pumped to another processing plant to be purified further for consumption.
Conclusion
The entire wastewater treatment process takes anywhere between 24 to 36 hours. The sewage treatment plants receive permits based on their flow rates, chemical levels, and effluent quality. Operators of the wastewater treatment plant must regularly make adjustments to the plant’s operation and constantly measure chemical levels to ensure proper treatment and discharge of water.
Inovar has been working for 5+ years to provide durable and reliable sewage treatment plants to industrial, commercial, as well as residential facilities around India. Apart from customized design and manufacturing of sewage treatment plants, we provide a range of key services critical to the smooth functioning of STPs including consultation, feasibility studies, project management, and more.
STPs from Innovar is backed by annual maintenance contracts and prompt post-sales service to ensure long and reliable service.
sewage treatment plant
wastewater treatment