Why Is Sewage Treatment Important? The Foundation of Safe, Sustainable Water Systems
Once we flush or pull the plug, it’s easy to forget where that water ends up. As soon as it is out of our sight, the thought of it also disappears. It is the end of our concern. But what happens next is important. Most of us fail to recognize that it is one of the most crucial processes. In this blog, let’s understand why is sewage treatment important, how it works, and what role it plays.
What Is Sewage?
Any wastewater that comes from homes, businesses, and industries is sewage. It can be a mix of harmful substances with organic waste, pathogens, chemicals, and solid materials.
It is a mix of harmful substances that includes organic waste, pathogens, chemicals, and solid materials. If left untreated, sewage can cause damage to the environment.
What Is Sewage Treatment?
Sewage treatment is the process of separating harmful pollutants from wastewater. This is to make the water safe enough for release to the environment. After sewage water treatment, this water can even be reused.
A standard sewage treatment plant uses physical, biological, and sometimes chemical processes to clean the water. The treatment involves removing solid waste, breaking down organic matter, and using filtration systems that remove remaining particles.
At the end of the sewage treatment process, we get treated water. Sometimes this water will be clean enough for reuse in non-potable applications.
Also Read: Modern Sewage Treatment Plant
Why Is Sewage Treatment Important?
The following are some reasons why sewage treatment is important:
- Protects Public Health
Untreated sewage is filled with dangerous bacteria, viruses, and parasites. If this water goes into rivers, lakes, or groundwater, it can lead to serious health threats. There are high chances for the spread of diseases like Cholera, Typhoid, Hepatitis, Gastrointestinal infections, etc.
Communities that are exposed to untreated sewage face higher risks of illness. This is unsafe, especially for children and senior citizens.
Proper sewage treatment stops these harmful pathogens from spreading and keeps people safe.
- Prevents Water Pollution
Water pollution has already become a global concern. When untreated sewage is dumped into rivers, lakes, or oceans, it pollutes them with organic matter that drains oxygen, harmful chemicals, and pathogens that pollute aquatic ecosystems.
This pollution kills fish and marine life. It also makes water unsafe for swimming and other uses. Sewage treatment plants help prevent this by reducing the load of contaminants entering water bodies.
- Protects the Environment
Sewage doesn’t just pollute water, it causes damage to the land and air. If not treated properly, it can contaminate soil with heavy metals or chemicals, and produce foul odours and harmful gases like methane.
By treating sewage with an efficient sewage treatment plant, it is possible to minimize these impacts and maintain a better environment.
- Supports Water Reuse
More and more places around the world are dealing with serious water shortages. One way to address this is by reusing treated wastewater. Treated sewage water can be reused for landscaping and irrigation, industrial cooling, toilet flushing, cleaning and maintenance, etc.
- Helps Meet Legal Standards
There are strict laws regarding how wastewater must be treated. If there is any failure to treat sewage properly, it can result in hefty fines for businesses. There are also chances for legal action against municipalities. As a result, sewage treatment plant manufacturers offer solutions that help industries stay within the law.
- Sustainable Development
Sewage treatment helps to reduce environmental impact, reuse valuable resources, and improve the quality of life in communities.
- Protects Drinking Water Sources
Rivers and lakes are often used as drinking water sources. If untreated sewage is dumped into these water bodies, it becomes very difficult and expensive to purify. By treating sewage before discharge in a proper way, it is possible to protect water sources and ensure clean drinking water.
How Sewage Treatment Works
- Preliminary Treatment (Screening & Grit Removal)
This preliminary treatment is done in order to remove large and solid materials from the sewage.
When wastewater enters a sewage treatment plant, it goes through screens and grit chambers. These are designed to filter out large debris like plastic bags, sticks, rags, stones, sand and gravel.
Large objects can damage equipment or block pipes later in the process. Removing them at the beginning makes the entire treatment process more efficient.
- Primary Treatment (Sedimentation)
This is for settling out solid particles.
The water is now moved into a large tank where it slows down. This allows heavier particles to settle at the bottom. These particles form are called as the primary sludge. The lighter substances, like grease and oils, float to the surface and are skimmed off.
What remains in the middle is partially clarified water. This water still consists of dissolved organic matter and tiny molecules.
Primary treatment removes around 50-60% of suspended solids. Once this treatment is completed, the wastewater will be prepared for further cleaning processes.
- Secondary Treatment (Biological Treatment)
Bacteria help break down the tiny organic particles still left in the water.
Microorganisms (mainly bacteria) are introduced to the wastewater. These tiny organisms feed on the organic pollutants, breaking them down naturally.
There are various procedures involved in secondary treatment are:
- Activated Sludge Process: Air is pumped into large aeration tanks to help bacteria grow and digest the waste.
- MBBR (Moving Bed Biofilm Reactor): Plastic media with biofilm help microorganisms cling and break down waste.
- SBR (Sequencing Batch Reactor): Wastewater is treated in batches, going through aeration and settling in the same tank.
After this biological treatment, the mixture is moved into a settling tank (secondary clarifier). At this stage, the persisting solids settle down and are removed as secondary sludge.
This step removes 85-90% of organic matter and harmful pathogens from the water and makes it much cleaner.
- Tertiary Treatment (Advanced Filtration and Disinfection)
To further purify the water for reuse or safe discharge.
Tertiary treatment is optional but essential when high-quality treated water is needed. It includes:
Filtration: Passing water through sand, charcoal, or membrane filters to remove remaining fine particles.
Disinfection: Killing any remaining bacteria and viruses using methods like:
- Chlorination
- UV radiation
- Ozonation
Some advanced systems also remove nutrients like nitrogen and phosphorus, which can cause algal blooms in water bodies if not treated. Tertiary treatment ensures the water is clean, clear, and safe for non-drinking reuse.
- Sludge Treatment & Disposal
- Safely treat and dispose of the solid waste.
Both primary and secondary treatment produce sludge. This sludge is thickened, digested, and sometimes dewatered using centrifuges or drying beds. In some plants, treated sludge is then processed and used as fertilizer or biofuel. Proper sludge management is important to avoid environmental contamination and reduce waste.
Also Read: Wastewater Treatment: Causes, Pros & Cons, and Plant Types
- Advanced Sewage Treatment Solutions
As one of the leading water treatment plant manufacturers, Alantech offers advanced and top-notch sewage treatment plants. Our sewage treatment plants are designed to meet the demands of modern residential, commercial, and industrial projects.
Alantech uses advanced biological treatment methods such as MBBR (Moving Bed Biofilm Reactor) and SBR (Sequential Batch Reactor). We customize each STP based on the client's needs, available space, and local discharge norms. For more information about sewage treatment plants, get in touch with Alantech.
