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  • Advanced Watertek

What is a Wastewater Treatment Plant?

Updated: Nov 7, 2022

Approximately 359 billion cubic metres of wastewater are produced across the world annually. This is equivalent to 144 million Olympic-sized swimming pools.

But where does this water go? Can it be released back into the environment? How is wastewater treated?

This is where a wastewater plant comes in. Wastewater plants carry out a series of water treatments that combine physical, chemical, and biological processes. The wastewater treatment system can be segregated into:

Before we explain how wastewater is treated, let’s first jump into the importance of the process.

What is the need for wastewater treatment?

Today, more than two billion people live in countries that are water-stressed. This situation is expected to worsen in the coming years with the increasing population and climate change.

Water is an indispensable part of our lives and crucial for survival. For this reason, it’s important to not only preserve and use it sustainably; we must monitor the quantity as well as the quality.

Wastewater contains elements that are toxic to humans and the environment. Polluted water is the cause of many health concerns and accounts for over 1.7 million deaths each year. It also causes diseases like cholera, schistosomiasis, and diarrhea.

Moreover, wastewater is also extremely hazardous to aquatic life. If polluted water gets discharged directly into rivers and oceans, it poses a great ecological risk. When elements like nitrogen and phosphates enter water bodies in large amounts, they result in oxygen depletion and dead zones: areas where fish and other aquatic flora and fauna can no longer survive.

By treating wastewater before releasing it into the environment, we can mimic the natural purification process of water and eliminate any harmful effects.

The wastewater treatment plant process has other benefits as well. Factories and industrial plants use massive quantities of water daily. Wastewater treatments allow these industries to reuse this water, thus saving thousands of liters of water being wasted.

Wastewater treatment is a serious matter. Many governments and municipal bodies have imposed fines for those who violate local laws regarding the release of polluted water into the environment.

How does a wastewater treatment plant work?

Now that you’ve understood the immense importance of treating wastewater, we reach the next big question: how does the process work?

There are several ways to treat wastewater. At Advanced Watertek, we select the suitable treatment method(s) depending on the results of the water analysis and as the intended use of the treated water. The water analysis gives us an insight into which contaminants are present in the water, as well as their quantities. Knowing the final use of the water, e.g., if it’ll be used for industrial purposes or human consumption, helps us determine just how pure it needs to be.

We can divide the methods for purifying the wastewater into three stages:


In pre-treatment, large solid particles are removed from the wastewater using physical processes like filtration and settling. Wastewater flows into the treatment tanks and basins as an influent, where large bar screens filter out larger items like tree limbs, leaves, and plastic debris. After this, equalization tanks (EQ tanks) regulate water flow to promote settling, and grit chambers allow small particles like dirt, sand, gravel, coffee grounds, and eggshells to be filtered out.

Primary Treatment

The next step in the wastewater treatment mode is the primary treatment. In this, smaller solids are removed from the wastewater through gravity and continued physical processes. The pretreated water is collected in primary clarifiers and is allowed to sit for a while so impurities can precipitate out. Mechanical scraping equipment can also be used to collect solid matter and send it toward the sludge treatment equipment to be part of the activated sludge process.

Secondary Treatment

In secondary wastewater treatment, bacterial and chemical processes are used to further purify the water. An example of secondary treatment is the use of beneficial microorganisms to break down more minute solid impurities in the wastewater.

What are the methodologies used in a wastewater treatment plant?

Advanced Watertek uses different combinations of processes to purify wastewater. Let’s learn more about some of the commonly used processes:


MBBR stands for Moving Bed Biofilm Reactor process. It is a biological water treatment process that is preferred due to its flexible, convenient and efficient nature.

MBBR takes place in a basin full of thousands of small plastic chips called carriers or media, which occupy between 40-60% of the tank. They provide a large surface area for biofilm to grow on and mix throughout the fluid rather than floating or sinking.

The bacteria and microorganisms in the biofilm consume the unwanted elements in the wastewater, making it cleaner and safer.


MBR stands for Membrane Bioreactor. This process combines different membrane treatments, like microfiltration and ultrafiltration, with biological treatment, like the activated sludge process.

First, semi-permeable membranes and sedimentation are used to filter solid particles. This allows the next step of biological treatment to occur more effectively.

MBR is commonly used for the treatment of municipal and industrial wastewater.

SAF System

SAF stands for Submerged Aerobic Fixed Film reactor. The Submerged Aerated Filter (SAF) system utilises a biological treatment process whereby highly aerated effluent flows through inert media that is completely submerged; fixed microbial film reduces the BOD and ammoniacal content of the effluent.

SAF systems are commonly used to treat residential and commercial wastewater, especially with a small to medium flow requirement.

SBR (Sequential Batch Reactor)

SBR stands for Sequencing Batch Reactor. It is a wastewater treatment wherein the contaminated water is added to a single batch reactor to remove undesirable particles through processes like aeration and clarification.

While treating water with SBR, two or more batch reactors are used in a pre-fixed sequence for best results.

SBR systems are commonly used to treat municipal and industrial wastewater in low-flow conditions.

The Bottom Line

If you’re struggling with wastewater treatment, partner with Advanced Watertek. We’re a leading water treatment company, an OEM, and an industry leader in membrane-based technologies for water treatment since 1984.

We’ve worked with global clients across several industries and provide the latest water treatment products.

Contact us to find out more about our custom membrane-based solutions.

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