Sewage Treatment Plants Manufacturer & Supplier  

Sewage Treatment Plants (STPs) are essential systems designed to remove contaminants, harmful chemicals, and pathogens from wastewater before it is safely discharged or reused. These plants ensure environmental safety, regulatory compliance, and sustainable water management for residential, commercial, and industrial applications. As a leading Sewage Treatment Plant Manufacturer & Supplier In Kolkata, we are proud to contribute to this vital mission by delivering advanced, efficient, and sustainable STP solutions across the country.

Sewage treatment plant: Understanding the basics of STP technology

A Sewage Treatment Plant (STP) is designed to treat and manage wastewater from households, industries, and commercial areas before releasing it back into the environment. STPs use a combination of physical, biological, and chemical processes to remove contaminants, solids, and harmful microorganisms from sewage. The key stages include primary treatment (screening and sedimentation), secondary treatment (biological degradation of organic matter), and tertiary treatment (advanced filtration and disinfection). By ensuring clean and safe water discharge, sewage treatment plants help protect public health, conserve water resources, and reduce pollution, making them essential for sustainable urban development and environmental safety.

What is a Sewage Treatment Plant & How does it work?


A Sewage Treatment Plant (STP) is a facility designed to treat and clean wastewater from households, industries, and commercial areas before releasing it into the environment. Its main purpose is to remove harmful contaminants, organic matter, and pathogens from sewage, ensuring that the discharged water is safe for reuse or disposal without polluting natural water bodies. With growing urbanization, STPs play a crucial role in protecting public health, conserving water, and maintaining ecological balance.

The working of a sewage treatment plant typically involves three main stages: primary, secondary, and tertiary treatment. In the primary stage, large particles, grit, and floating solids are removed through screening and sedimentation. The secondary stage uses biological processes where microorganisms break down organic matter, reducing pollutants like Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD). Common methods include activated sludge processes, biofilters, and aeration tanks. Finally, in the tertiary stage, advanced treatment techniques such as filtration, chlorination, UV disinfection, or membrane processes are applied to eliminate remaining pathogens, nutrients (like nitrogen and phosphorus), and suspended solids.

After treatment, the cleaned water, known as effluent, can be safely discharged into rivers, lakes, or reused for irrigation, gardening, industrial processes, and even toilet flushing. The sludge collected during treatment is further processed and can be used as fertilizer or for energy generation.

What type of waste does sewage contain?

Sewage typically contains large amounts of organic waste and may also include harmful inorganic substances. If untreated sewage is discharged directly into rivers, streams, or other water bodies, it can lead to severe water pollution and pose serious health risks to humans and aquatic life. Proper sewage treatment is essential to remove contaminants and prevent the contamination of freshwater sources. This is why treating sewage before releasing it into the environment is crucial for protecting public health and preserving ecosystems.

Sewage Treatment Plant process

Sewage can be treated by designing a sewage treatment plant (STP) which involves three stages: primary/preliminary, secondary and tertiary.

Primary Treatment

In a sewage treatment plant, sewage water is first allowed to pass through screens or grit chamber where large solids are removed. This step is followed by aeration/mixing in a tank and then primary sedimentation where suspended solids settle down. Primary treatment involves addition of a coagulant and aims at removing grits, coarse solids, oil and grease if any present. Preliminary treatment results in sedimentation of solids (sludge) and formation of an effluent that floats above sludge. Effluent from primary treatment consists of 45-50 % unstable organic matter. The effluent then undergoes secondary treatment where fine solids settle out by means of bacterial activities.

Secondary or Biological Treatment

The biological treatment stage of sewage treatment plays a vital role in converting organic matter into stable forms through microbial activity. This stage leads to secondary sedimentation, where suspended solids settle out of the treated water. Two widely used methods for this process are trickling filters and the activated sludge process.

Trickling Filters
Trickling filters consist of a tank filled with a bed of course materials like bricks or stones, coated with a layer of microorganisms. As the sewage effluent enters the tank through an inlet, it is sprayed over the filter bed using rotating sprinklers. The microorganisms break down and oxidize the organic matter present in the wastewater. This process reduces organic pollutants, removes fine solids, and forms sludge, resulting in a cleaner effluent with lower organic content.

Activated Sludge Process
In the activated sludge method, a mixture of active microorganisms (biomass) is added to sewage in an aeration tank. Continuous aeration and agitation provide aerobic conditions that enhance microbial growth and activity. These microbes oxidize the organic waste, leading to coagulation, flocculation, and settling of solid particles. This process results in a clear, odor-free effluent, making it an efficient solution for secondary sewage treatment.

Both methods are crucial in reducing pollution load and ensuring the treated sewage is safe for discharge into natural water bodies.

Tertiary Treatment

The effluent then undergoes tertiary treatment/disinfection by incorporation of UV radiation or chlorination. Other methods such as sand filters and reverse osmosis may also be used instead for this stage of treatment, depending upon the nature of the sewage and the effluent from secondary treatment.

We have the best deals for Top 10 sewage treatment plants at our Indian Trade Birds for our beloved consumers. We are leading manufacturer, supplier, exporter and retailer of Sewage Treatment Plant 135 KLD, Sewage Treatment Plant, STP Plant, HEXON Sewage Treatment Plant, Sewage Treatment Plant 10 KLD, Sewage Treatment Equipment, Package Sewage Treatment Plant, SEWAGE DRAINAGE PUMP, Sewage Water Treatment Plant, Commercial Sewage Treatment Plant, Prefabricated Packaged Sewage Treatment Plant, Industrial Sewage Treatment Plant, Domestic Sewage Treatment Plant, Sewage Treatment Plant For Hospital, providing high-quality solutions for industrial, commercial, and domestic wastewater management. Our advanced STP plants are designed to ensure efficient sewage treatment, easy operation, and long-lasting performance, making us the trusted choice for reliable, sustainable, and cost-effective sewage treatment systems across India.

                                                                                                                                                                        Popular searches 
Sewage Treatment | Sewage Treatment Plants | Sewage Treatment Plants (STPs) | Sewage Wastewater Treatment Plants | Sewage Treatment Plant Process | Sewage Treatment Plant Project | Sewage treatment PPT | Sewage Treatment Plant Manufacturers | Sewage Treatment Plant Supplier | Sewage Treatment Plants Near Me | Sewage Treatment Plants Types |
Sewage Treatment Plant Process Flow Diagram


FAQ's

What is the difference between STP and ETP?

  • STP: Treats domestic sewage

  • ETP: Treats industrial effluents which may contain chemicals and toxic substances

What are the key features of a sewage treatment plant?

  • Multi-stage treatment process – Primary, secondary, and sometimes tertiary treatment for efficient wastewater purification.

  • Solid waste removal – Settling tanks and screens to eliminate suspended solids and debris.

  • Biological treatment – Aeration and activated sludge systems to break down organic matter.

  • Automation & control systems – For efficient monitoring and operation.

What is the working principle of a sewage treatment plant?
The working principle of a sewage treatment plant involves removing contaminants from wastewater through physical, biological, and chemical processes. It typically includes sedimentation to remove solids, aeration for biological treatment, and filtration or disinfection to ensure the water meets environmental standards before discharge or reuse.

What are the types of sewage treatment plants?

  • Primary Treatment Plants – Remove large solids and sediments from wastewater.

  • Secondary Treatment Plants – Use biological processes to break down organic matter.

  • Tertiary Treatment Plants – Further purify water by removing nutrients, chemicals, and pathogens for safe discharge or reuse.

What is a sewage treatment plant?
A sewage treatment plant is a specialized facility designed to treat both domestic and industrial wastewater. It operates through a series of reinforced concrete (RCC) units integrated with electromechanical systems. These components work together to reduce the concentration of contaminants by removing solid particles and silt, while also regulating the physical and chemical properties of the sewage.

Why do we need a sewage treatment plant?

If this type of treatment is not done, it would be very difficult to maintain wastewater under control & to handle problems or diseases that would arise from air & water pollution.

What are the 4 stages of sewage treatment?

The stages of sewage treatment plants are, 1. Screening & Pumping, 2. Grit Removal, 3. Primary Settling, 4. Aeration / Activated Sludge, 5. Secondary Settling, 6. Filtration, 7. Disinfection, 8. Oxygen Uptake,9. Sludge Treatment.

What is the process of sewage treatment plants?

A Sewage Treatment Plant operates by airflow which stimulates the growth of bacteria to break down sewage. The aim of this treatment is to deliver much cleaner and environmentally friendly effluent.

What are the 3 stages of sewage treatment?

The three main stages of the waste treatment process which is classified into Primary, Secondary & Tertiary Water Treatment.

Scroll to Top