STP Plant – A Sewage Treatment Plant is a facility designed to treat and purify wastewater, also known as sewage or domestic wastewater before it is released back into the environment. The primary goal of an STP is to remove contaminants, pollutants, and harmful microorganisms from the sewage to ensure that the treated water does not cause environmental pollution and is safe for discharge or reuse.
How sewage treatment plant works:
- Preliminary Treatment
- Large solid objects like sticks, leaves, and debris are removing from the incoming wastewater using screens and grit chambers.
- This step helps prevent damage to downstream equipment and ensures that the treatment process is efficient.
2. Primary Treatment
- The wastewater flows into settling tanks or clarifiers, where the flow velocity is reducing.
- Heavy solids and particles settle to the bottom, forming a layer of sludge, while lighter materials like grease and oils float to the surface. The sludge and scum are collecting and sent for further treatment.
- Primary treatment primarily aims to remove settleable and floatable solids from the wastewater.
3. Secondary Treatment (Biological Treatment):
- The pre-treated wastewater moves to the biological treatment phase, where microorganisms (bacteria and other microbes) break down organic matter in the water.
- The most common method used is the activated sludge process. Here, the wastewater is mixed with a culture of microorganisms in aeration tanks. These microorganisms consume the organic matter present in the water, transforming it into carbon dioxide, water, and more microorganisms.
- Aeration provides oxygen for the microorganisms’ metabolic activities, promoting efficient organic matter breakdown.
4. Tertiary Treatment
- Tertiary treatment, also known as advanced treatment, further refines the water quality to meet specific standards or to prepare it for reuse.
- Advanced filtration methods like sand filtration, membrane filtration, or advanced oxidation processes (AOPs) are using to remove remaining suspended solids, nutrients (such as phosphorus and nitrogen), and trace contaminants.
- After secondary or tertiary treatment, the treated water undergoes disinfection to eliminate harmful bacteria, viruses, and pathogens.
- Common disinfection methods include chlorination, ultraviolet (UV) radiation, and ozonation.
6. Sludge Treatment
- The sludge collected from primary and secondary treatment stages undergoes further treatment processes.
- Anaerobic digestion is a common method to reduce the volume of sludge, produce biogas (methane), and stabilize the organic matter.
- Dewatering processes like centrifugation or mechanical pressing remove excess water from the sludge, reducing its volume and making it easier to handle and transport.
- Depending on local regulations and conditions, the treated sludge can be using for land application, incineration, or other beneficial reuse options.
7. Effluent Discharge or Reuse
The final treated effluent, which has undergone primary, secondary, and possibly tertiary treatment, is now of a quality suitable for discharge into water bodies or for reuse in non-potable applications like irrigation, industrial processes, or groundwater recharge.
Sewage Treatment Plant Benefits
- Proven technology which offers reliable performance
- Preserves the natural environment against contamination and pollution.
- Helps to meet the standards for the emission of pollutants set by the Government and avoid heavy penalties.
- Simple and easy to install.
- Requires Low maintenance.
- Reduces risk to public health and the environment.
With the latest technologies, Kelvin Water Technology Pvt. Ltd. offers consulting and project execution for STP Plants (Sewage Treatment Plants), such as FAB (Moving Bed Bioreactor) and SAFF (Sewage Treatment Plant)-based Treatment Plants, Advance Treatment Plants, etc. As per the client/customer requirements, site conditions, and area availability, we can provide either automatic, semi-automatic, or manual operation for these plants.