Sewage Treatment Plant

April 4, 2023

What is a sequence batch reactor and how it works?

Industrial wastewater treatment tanks are known as sequential batch reactors (SBR) or sequencing batch reactors. Batch processing of wastewater from anaerobic digesters or mechanical biological treatment facilities is done in SBR reactors. Wastewater is bubbled with oxygen to reduce its biochemical and chemical oxygen demands, allowing it to be disposed of in sewers or applied to land. SBRs can take many different forms, but the fundamental process never changes and we will discuss What is a sequence batch reactor (SBR) and how it works?

The system comprises at least two identically equipped tanks that share an interchangeable intake. The tanks are designed with a “flow-through” mechanism that enables untreated wastewater to enter one end and treated water to exit the other.

The other tank is aerating and filling while the first is settling and decanting. The tank’s bio-selector is a component that is situated close to the intake. This is composed of a series of baffles or barriers that direct the flow under and over one baffle to the next, or from one side of the tank to the other. This helps to mix the influent coming in and the activated sludge coming back out, starting the biological digestion process before the liquor hits the main tank.

How does sequencing batch reactor (SBR) work?

Within the therapeutic process, there have been five stages:

  • Fill
  • React
  • Settle
  • Decant
  • Idle

The input valve opens first, allowing the container to be fed, then physical mixing takes place without the addition of air. The anoxic stage is another name for this. The combined liquor is aerated using physical pumps that are fixed or float or by air movement through fine bubble diffusers that are positioned at the bottom of the tank in the second stage. In the third stage, there is neither aeration nor stirring, and the settling of suspended particles starts. The fourth stage involves opening the outlet valve to let the “pure” supernatant liquor leave the tank.

Configuration of the SBR Process

SBRs must have the following components:

  • reactor basin
  • The mechanism for removing waste sludge
  • equipment for aeration
  • decanter for effluent

System of process control

To enable the continuous input of wastewater, the SBR system typically consists of a storage/equalization tank, one SBR tank, or at least two tanks. As with conventional activated sludge treatment systems, conventional screening and grit removal are typically used as preliminary treatments. In most cases, SBR systems do not need a first sedimentation stage unless the influent suspended particle concentration is quite high.

Settled sewage can also be treated if the SBR is positioned downstream of the current primary settlement tanks. Reactors are typically simple steel or concrete tanks that are round, square, or rectangular in shape. Both lagoon projects and already-built tanks, including primary sedimentation tanks, can be used. The treatment plant as a whole requires fewer buildings, enabling a more compact site layout because the tank serves as both an aeration tank and a final clarifier.

Multi-sequencing batch reactor transformation

The owner may decide to change their current method into a multi-SBR facility when a typical treatment plant is unable to provide enough treatment due to increasing loading rates, stricter treatment standards, and other issues. The need for SBR sludge management will decline as a result of the conversion to SBR because the sewage age will be prolonged.

Advantages of SBR

  • It uses aeration intensity modulation to achieve concurrent (co-current) nitrification and de-nitrification.
  • It runs on simple cycle changes and continuously decreasing loads.
  • It prevents filamentous sludge bulking while also ensuring endogenous respiratory rate (expulsion among all available substrates), nitrification, and de-nitrification, as well as improved biological phosphorus withdrawal. It does this by using feed-starve selectivity, So/Xo operation (regulation of the restricting substrate to microorganism proportion), and aeration intensity.
  • It can withstand shock loads brought on by changes in hydraulic and organic load. The approach is simple to put into practice and may be altered to take into account both short-term diurnal and long-term climatic fluctuations.
  • It does away with the requirement for an additional clarifier.
  • It eliminates the need for separate load balancing. With a much lower solids flow than a typical clarifier design, the SBR basin serves as both an equalization basin and a clarifier.
  • It may naturally eliminate nutrients without the use of chemicals by regulating the supply and demand for oxygen;
  • Via nutrient elimination mechanisms, it maximizes energy. The oxygen rate and energy requirements are significantly reduced by the carbonaceous BOD in feed water employed in denitrification and better biological phosphorus removal.
  • It’s operating and capital costs are lower.

To contact Netsol Water, call on +91 9650608473 or send an email to

February 28, 2023

Top 10 Tips to Reduce BOD or TSS in Sewage Treatment

Total Suspended Solids (TSS) and Biochemical Oxygen Demand (BOD) are two of the most crucial parameters in wastewater treatment (BOD). You may already be aware of the significance of controlling your TSS and BOD for the following key factors:

  • TSS/BOD levels need to meet state environmental protection laws.
  • High TSS levels can hurt wildlife badly and make water tasteless or even harmful to human health.
  • High TSS levels can harm your wastewater equipment and affect its performance.
  • Aquatic life can be harmed or killed by high BOD.

Fortunately, there are some simple ways to maintain control over your BOD and TSS. The greatest techniques for minimizing BOD and TSS that facility managers should be aware of are as follows:

1. Focusing first on reducing TSS from wastewater.

TSS reductions usually always occur with BOD reductions. To remove large solids, start by using mechanical screens like roto-strainers or bar screens. Also, this will prevent blockage or damage to your downstream DAF (dissolved air flotation) equipment.

2. Obtain an EQ tank that is the right size.

Excessive amounts or underfeeding of flocculants and coagulants can result from changes in flow and loading rates. Your flow and loading rates will be more distributed equally with a properly sized EQ tank. Also, this will aid in the right sizing of the polymer make-down feeder, reducing your startup expenses.

3. Optimize the waste stream’s pH.

There is a certain pH range where effective wastewater treatment chemistry works at its maximum effectiveness. The polymer will be wasted or rendered useless if the pH moves up and down to either side of this window.

4. Add a plastic or stainless steel DAF plate pack that is the latest.

Your TSS removal rates will increase with a current plate pack DAF. Also, it will reduce the DAF’s footprint and give you more flow and load sensitivity latitude.

5. Utilize an air dissolution pump with a regenerative turbine.

An aeration pump with a regenerative turbine consumes minimal electricity to dissolve air in the water and create 20–30–micron air bubbles. They are essential for the effective treatment of DAF.

6. Purchase a DAF that self-cleans.

Around every two weeks, takedown and cleaning are needed for modern high-rate DAFs. Also, forgetting to clean it could result in blockage, issues with solids separation, increased chemical input rates and increased TSS. Choose a DAF that is self-draining and self-cleaning to save yourself a lot of work compared to cleaning it yourself. Cleanout valves or pumps are provided by properly built DAF systems to remove resistant, heavy, settled solids.

7. When possible, use liquid chemistry that has been performance-tested.

Liquid chemistry opens up a huge variety of treatment chemistries, removes wetting difficulties and fish eyes (clumps of undissolved polymer particles), and enables complete automation of the process at a reasonable cost. Also, switching products is considerably simpler than waiting or throwing away a palette of dry bag polymer when a drum or tote runs out.

8. Use a system for flow-proportional dosing and make-down.

You should still utilize a flow proportional dosing system to allow for flow cycling even if your EQ tank is the correct size. A flow metre with a 4-20 ma output signal to the chemical feed system is what you want to find. More consistency, better overall treatment removal, and less chemical use will result from this.

9. Find and test the appropriate chemical injection locations.

The coagulant should ideally be transfused initially, as far upstream as possible. In advance of the transfer pump, here is where the wastewater would exit the EQ tank. Fill a pot on the flocculation tube with the polymer. To determine the coagulant dose for pin floc production, a sample tap needs to be put in front of the polymer injection port. Prior to entering the DAF, a sample port downstream of the polymer injection port analyzes the efficiency of your chemicals. Before the effluent exits the DAF, you can then make modifications.

10. Require DAF equipment of the proper size.

The effects of chemical therapy are limited. Poor TSS removal rates and chemical treatment failure will come from a DAF or chemical feed equipment that is too small. The output and flow rates of organizations are constantly rising, so you need to size your equipment with future increases in mind. Many of these problems are the consequence of a breakdown in the operation or maintenance of the DAF equipment, not the chemical program.

Netsol Water is Greater Noida-based leading water & wastewater treatment plant manufacturer. We are the industry’s most demanding company based on client review and work quality. We are known as the best commercial RO plant manufacturersindustrial RO plant manufacturerssewage treatment plant manufacturersWater Softener Plant Manufacturers, and effluent treatment plant manufacturers. Apart from this 24×7 customer support is our USP. Call on +91-9650608473, or write us at for any support, inquiry, or product-purchase-related query.


February 18, 2023

What is a Sewage Treatment Plant?

Sewage treatment plants are designed to treat and purify wastewater generated by households, industries, and commercial companies. The wastewater includes human and animal waste, food waste, cleaning products, and other contaminants.

The primary objective of a sewage treatment plant is to remove contaminants and pollutants from wastewater so that it can be safely disposed of or recycled for other uses. A sewage treatment plant typically consists of several stages, including primary, secondary, and tertiary treatment.

The primary treatment involves removing heavy solids and organic matter from the wastewater through a physical process such as sedimentation and screening. The secondary treatment is a biological process that includes removing the organic matter using microorganisms. The tertiary treatment, on the other hand, involves removing any remaining contaminants from the water through chemical or physical processes.

Sewage treatment plant manufacturers are essential to maintaining a clean and healthy environment. Untreated wastewater can have a significant impact on human health and the environment. It can lead to the spread of diseases, contaminate soil and water, and damage aquatic life.

Types of Sewage Treatment Plants

There are several types of sewage treatment plants, each with its own set of features and benefits. The most common types of sewage treatment plants include:

Activated Sludge Process (ASP)

The activated sludge process is the most commonly used sewage treatment plant. It involves introducing air into the wastewater to encourage the growth of microorganisms that break down organic matter. The process is effective in removing contaminants such as nitrogen and phosphorus.

The activated sludge process is widely used because it is effective in removing organic components and fertilizers from wastewater, and can be operated with a relatively small footprint. However, it can be energy-intensive due to the need for aeration and can also produce large amounts of excess sludge that require disposal or further treatment. As a result, modifications to the process, such as the use of advanced treatment technologies or the implementation of a sludge reduction program, may be necessary to optimize its performance and reduce its environmental impact.

Activated Sludge Process

Extended Aeration Process (EAP)

The extended aeration process is similar to the activated sludge process, but it involves a longer retention time. This allows the microorganisms to break down the organic matter more effectively, resulting in a higher quality of effluent.

The extended aeration process is known for its ability to produce high-quality effluent, even under variable or low wastewater flow conditions. It also typically requires less energy than other types of activated sludge processes, as the slower rate of microbial growth and longer aeration time results in less oxygen demand. However, the extended aeration process may require a larger footprint due to the larger aeration tank required and can produce more sludge than other processes, which may require additional handling and disposal.

Extended Aeration Process

Sequential Batch Reactor (SBR)

The sequential batch reactor is a batch process that involves alternating between anoxic and aerobic conditions. This process allows for the removal of nitrogen and phosphorus from the wastewater.

SBRs can operate using either aerobic or anaerobic conditions, depending on the specific treatment needs. In the aerobic SBR, air is provided to the tank during the reaction phase to provide oxygen for the microorganisms. In the anaerobic SBR, the treatment occurs in the absence of oxygen, allowing anaerobic microorganisms to break down organic matter.

Sequential Batch Reactor

Membrane Bioreactor (MBR)

The membrane bioreactor combines biological treatment with membrane filtration to produce high-quality effluent. The process is efficient in removing solids and contaminants from the wastewater.

MBRs can use either submerged or external membrane filtration. Submerged MBRs place the membrane directly into the aeration tank, while in external MBRs, the membrane is placed in a separate tank and the mixed liquor is pumped through the membrane.

Membrane Bioreactor

Moving Bed Biofilm Reactor (MBBR)

The moving bed biofilm reactor involves attaching biofilm to plastic carriers that move freely in the wastewater. The process is effective in removing organic matter and nitrogen from the wastewater.

In an MBBR, wastewater flows through a reactor tank containing the suspended biofilm carriers, which provide a surface for the growth of microorganisms. The aeration or mixing of the wastewater ensures that the biofilm carriers are constantly moving and in contact with the wastewater, which promotes the growth of the microorganisms on their surface.

As the wastewater flows through the reactor, the microorganisms on the biofilm carriers consume organic matter, converting it into biomass and other byproducts. The treated wastewater is then discharged, while the biofilm carriers are recycled back to the reactor tank.

Moving Bed Biofilm Reactor

Sewage Treatment Plant Manufacturers – Expert Solutions for Your Wastewater Treatment Needs

Choosing the right sewage treatment plant manufacturer is essential to ensure the quality and efficiency of the plant. Here are some of the top sewage treatment plant manufacturers:

Netsol Water

Netsol Water  Top Most leading Sewage Treatment Plant Manufacturer in India, starts manufacturing new wastewater machines –  Sewage Treatment Plant 5kld5kld packaged STP, Sewage Treatment Plants, and Zero Liquid Discharge Plants to safeguard “ Mother Earth Resources ”  – Save Water Now !!!
Netsol Water is always ready to solve problems and fulfill the expectations of our clients through the Netsol research wing. For this time we’re ready by Adopting and enhance the Best European Technology for “Compact STP”, And Launch a new Product Named- “Compact Sewage Treatment Plant“. This is for those Households, Hotel, Resorts, Farmhouses, and Schools who have low spaces or want a compact wastewater treatment plant at their place which take a low space and works efficiently & effectively.

Factors to consider when choosing a sewage treatment plant manufacturer

Urban STP plant

Urban STP Plant Top Most driving Conservative Sewage Treatment Plant Producer in India, begins fabricating other wastewater machines – Smaller Sewage Treatment Plant 5kld, 5kld bundled STP, Sewage Treatment Plants, and Zero Fluid Release Plants to shield ” Mother Earth Assets ” – Save Water Now.

Sewage Treatment Plants

We are the Sewage Treatment Plants (A Unit of Netsol Group & Research), having the best solution by STP Plant Manufacturer for waste and wastewater treatment. Since our establishment in the year 2012, we are one of the most trusted partners for waste management solutions. And integrated service providers of design, fabrication, installation, and maintenance services. With our years of expertise, we are the leading service provider for solutions, testing, monitoring, analysis, and recommended corrective actions in the field of waste and wastewater solutions.
We are the best solution provider for treating sludge and industrial effluent to save water as well as to save mother earth.

With our best innovation of Green Waste Converter Machine, we are daily converting thousands of kilo composite by treating Green and organic waste.

Factors to consider when choosing a sewage treatment plant manufacturer

Choosing a sewage treatment plant manufacturer is a decision that should be taken seriously. It is important to choose a manufacturer that provides quality products and services. Here are some factors to consider when choosing a sewage treatment plant manufacturer:

Experience: It is important to choose a manufacturer that has been in the industry for a significant amount of time. An experienced manufacturer is likely to provide better products and services.

Reputation: A good reputation is a clear indication of a manufacturer’s ability to deliver quality products and services. You can check the manufacturer’s website for customer reviews and testimonials.

Quality of products: The quality of products is a critical factor to consider. It is important to choose a manufacturer that provides high-quality products that meet your specific needs.

Customer service: Good customer service is important in any business. Choose a manufacturer that provides excellent customer service and is always available to answer your questions and address any concerns.

Price: The cost of the products and services is a significant factor to consider when choosing a manufacturer. It is important to choose a manufacturer that provides quality products and services at a reasonable price.

Why Choose Us?

We are one of the top manufacturers of sewage treatment plants in India, with years of experience and a track record of providing dependable and effective solutions to our customers. All sizes and capacities of sewage treatment plants can be designed, installed, and maintained by our team of professionals due to their technical skills and knowledge.

We offer a wide range of solutions, including:

  • Traditional sewage treatment plants
  • Packaged sewage treatment plants
  • Membrane bioreactor (MBR) plants
  • Sequential batch reactor (SBR) plants
  • Extended aeration (EA) plants
  • Moving bed biofilm reactor (MBBR) plants

All our solutions are designed to meet the highest quality standards and are backed by excellent after-sales service and technical support.

FAQs about sewage treatment plant manufacturers

What is a sewage treatment plant?

A sewage treatment plant is a facility that processes and treats wastewater to remove contaminants and produce clean water that can be safely discharged into the environment.

Why is it important to choose a reputable sewage treatment plant manufacturer?

Choosing a reputable sewage treatment plant manufacturer ensures that you receive high-quality products and services that meet your specific needs.

What are the different types of sewage treatment plants?

The different types of sewage treatment plants include conventional sewage treatment plants, package sewage treatment plants, and mobile sewage treatment plants.

How long do sewage treatment plants last?

Sewage treatment plants can last for up to 20-30 years, depending on the quality of the products and the maintenance practices.

What factors should I consider when choosing a sewage treatment plant?

The factors to consider when choosing a sewage treatment plant include the size and capacity of the plant, the quality of the products, the reputation of the manufacturer, and the cost of the products and services.

Sewage Treatment Plant Manufacturer in India
Sewage Treatment Plant Manufacturer in India


February 3, 2023

The Actuated Sludge (AS) process is as of now the most broadly utilized biological wastewater treatment process in the world.

Since its conception in the late nineteenth hundred years and resulting improvement into a full-scale process in 1913 by Arden and Lockett at the Davyhulme sewage treatment works in Manchester, the essential cycle has been broadly taken on and further created providing it with an exceptional adaptability of activity.

Activated Sludge Process and Types for Wastewater Treatment: Everything You Need to Know

In the Activated Sludge Process (ASP) for wastewater treatment, microorganisms, including microbes, bacteria, fungi, and protozoa, are utilized to accelerate the decomposition of organic matter requiring oxygen for treatment.

In this Activated Sludge Process (ASP), microorganisms are totally blended in with organics under conditions that stimulate their growth, and waste materials are eliminated. As the microorganisms grow and are blended by the agitation of the air, the individual microorganisms cluster and flocculate together to shape a mass of organisms called activated sludge.

Activated Sludge Meaning

The Activated Sludge name and meaning start from the process it includes the development of an initiated mass of microorganisms equipped for vigorously settling the organic content of wastewater, subsequently, it is “activated”.

Conventional Activated Sludge System in Water & Sewage Treatment

An ordinary activated sludge system for sewage treatment incorporates:

  • The aeration tank where the biological responses occur;
  • An aeration source that gives oxygen, mixing and blending;
  • A tank, known as the clarifier, where solids settle and are isolated from treated wastewater;
  • A collecting means for the solids either to return to the aeration tank, returned activated sludge, or eliminate from the process (waste-activated sludge).

A total complete system for sewage treatment incorporates chlorinators, holding tanks, pumps, and a control system that screens the treatment effectiveness.

Activated Sludge Plant Components and Design

The Activated Sludge Plant (ASP) comprises a balance bowl, PST, an aeration tank, an secondary settling tank (SST), and a sludge reuse line.

Feed wastewater is homogenized in an equalization basin to reduce varieties in the feed, which might cause process upsets of the microorganisms and reduce water treatment effectiveness.

In the aeration tank, the aerobic bacterial population is kept up in suspension in the blended liquor and oxygen, as well as supplements are given. Oxygen is provided either by mechanical or diffused aeration, which additionally helps with keeping the microbial population in suspension. The blended liquor is consistently released from the aeration tank into a secondary clarifier in a wastewater and sewage treatment system.

Efficient & Effective Activated Sludge Process Design

The Activated Sludge process offers proficient and effective removal of BOD, COD, and supplements when designed professionally and worked appropriately. The actual process has flexibility and various modifications can be custom-made to meet specific requirements (for example for nitrogen removal).

Activated sludge is a complex mix of microbiology and biochemistry including a wide range of kinds of microorganisms. In the Activated Sludge Plant (ASP) microbes, bacteria secrete sticky substances that coat the minute particles conveyed in sewage. The particles remain together to shape flocs of a gel-like material, making help on, and in which, organisms exist. This is the brown-colored activated sludge.

The activated sludge is circulated to dissolve oxygen which permits the organic matter (BOD) to be used by the microbes. The organic matter, or food, adheres to the activated sludge. The oxygen dissolved in the water allows the microbes to utilize the food (BOD) and furthermore to change the ammonia to nitrate. The activated sludge tank should be big enough to allow sufficient contact time (retention time) between the sewage and the activated sludge for every one of the chemical changes to take place.

Return Activated Sludge (RAS)

The settled biomass, called Return Activated Sludge (RAS), is then returned to the start of the aeration process where it will retain new sewage to begin the interaction in the process again. This enables the process to operate as a continuous cycle.

At the point when the Activated Sludge reaches the finish of the process it is as yet an exceptionally active biomass, however, is currently blended in with purified effluent. It is moved to Settlement Tanks (Secondary Clarifiers) to permit separation from the purified effluent which might be released to the river or to some type of tertiary treatment.

Surplus Activated Sludge (SAS)

The Surplus Activated Sludge (SAS) is wasted by constantly pulling out a portion of the RAS for sludge disposal.

As a matter of fact, as the RAS mixing in with the new sewage will produce a slow development in the activated sludge present it is necessary to waste a certain quantity each day.

Activated Sludge Types

There are nine types of activated sludge processes:

  1. Tapered Aeration
  2. Step Aeration
  3. High-Rate Treatment or Modified Aeration
  4. Two Stage Aeration
  5. Activated Aeration
  6. Reaeration
  7. Contact Stabilization
  8. Complete Mix
  9. Extended Aeration Method


1- Tapered Aeration or Controlled Aeration

Tapered aeration is also called controlled aeration. Assuming examples are gathered at different places in the aeration units, it will be observed that the BOD of the mixing liquor isn’t uniform all through; it is most extremely close to the channel and least close to the power source. Because of this explanation on the off chance that the diffused air is applied at a uniform rate, it can’t be used as expected.

2- Step Aeration

Assuming that the sewage is added to the returned sludge at multiple focuses along the aeration channel, the load coming on the returned sludge is changing. In the past article, it has been expressed that the BOD of the mixed liquor is different at various places.

3- High-Rate Treatment or Modified Aeration

In the high-rate treatment (or Modified Areation) technique, less quantity of returned sludge is used, consequently, it is called high-rate treatment. In high-rate treatment shorter detention period (2 hours), a lesser amount of packed air, and a small amount of returned sludge are used.

4- Two-Stage Aeration

In two-stage aeration, the sewage is permitted to flow in a couple of aeration and sedimentation units. The activated sludge is either returned for the purpose of cultivating or excess sludge from the second stage is again sent off the first cycle from which both of it and the excess of the first stage are mixed with influent.

5- Activated Aeration

It is a combination of two tapered activated sludge plants equal involving similarly settled sewage as influent. The inordinate activated sludge of one plant is used as seed for another plant, which is called activated aeration.

6- Reaeration

In this technique, the minimum aeration of sewage is finished in the wake of adding returned sludge to it. To fulfill the BOD reaeration of returned sludge is finished prior to mixing it in with the sewage. On the off chance that the reaeration is finished in advance of the trickling filter, it is called bio aeration.

7- Contact Stabilization

The contact adjustment is also called biosorption. In this process, sewage might be dealt with either after primary settling or without primary settling. The sewage is aerated through alongside return sludge for a comparatively short period of 0.5 to 1.5 hrs. when the sludge absorbs the organic matter in the sewage.

The mixed liquor is then settled in a secondary settling tank. The return part of the sludge removed from the settling tank is reaerated in a different sludge reaeration tank for a time of 3-6 hrs. before it is taken care of once more into the contact aeration tank. During the reaeration of the sludge, the absorbed organics are settled restoring the adsorptive capacity of the sludge.

8- Complete Mix

The complete mix-activated sludge process utilizes a totally mixed flow system. In a rectangular tank, complete mixing is achieved by distributing the sewage and the return sludge consistently along one side of the tank and withdrawing the aerated sewage, consistently along the opposite side. In the case of a round or square tank, complete mixing is achieved by a mechanical aerator with adequate mixing capacity installed at the center of the tank.

9- Extended Aeration Method

The flow plan of the extended aeration process and its mixing system are like that of the total mixing process. The oxidation ditch likewise adjusts to the drawn-out aeration guideline and depends on aeration through the mixing of liquor in an endless ditch. Primary settling is discarded in the drawn-out extended aeration method, however, condemnation is often provided for screenings.

January 6, 2023

According to the legal guidelines for Sewage Treatment Plants given by CPCB, different infrastructures like Apartments, Commercial Development Projects, Educational Institutions, Municipalities, and Area Advancement Undertakings meeting specific models need to introduce STPs for the treatment of sewage that they produce, and every sewage treatment plant manufacturers have to follow it.

The guideline rules cover angles in regards to the area of STPs, the STP technology to take on, working as well as its maintenance to guarantee effective and safe activity of the machinery.

The Guidelines given for STPs by CPCB Guidelines for Sewage Treatment Plants are as per the following:

CPCB Guidelines for Sewage Treatment Plants

1. The Technology of STP

The approved STP technologies to go with are-

  1. Activated Sludge Process (ASP) (just when over 500 KLD sewage is generated).
  2. Membrane Bio Reactor (MBR)
  3. Moving Bed Bio Reactor (MBBR)

2. Unit Requirements of STP

STPs have different individual units where different sewage treatment processes happen. The units and their criteria according to the guideline’s prerequisite are as per the following.

SNo. Unit Activated Sludge Process (ASP) Sequential Batch Reactor (SBR) Membrane Bio Reactor (MBR) Moving Bed Bio Reactor (MBBR)
1 Equalization Tank Should have a minimum holding period of 8 hours Same as ASP Same as ASP Same as ASP
2 Anoxic Tank Return activated sludge should be pumped to anoxic tank for denitrification. Not Required Same as ASP Same as ASP
3 Aeration Tank Dissolved Oxygen in an excess of 4 mg/L has to be maintained in the Aeration Tank. Same as ASP Same as ASP Same as ASP
4 Membrane Tank Not Required Not Required Membranes should be replaced regularly as per its manufacturer’s specifications Not Required
5 Sludge Holding Tank Sludge holding should be madatoriliy provided for holding excess sludge before its dewatering. Same as ASP Same as ASP Same as ASP
6 Final Treated Water Holding Tank Capacity of the tank should be enough to hold water for 2 days minimum. Same as ASP Same as ASP Same as ASP
7 Sludge Drying Bed Instead of sludge drying bed, horozontal centrifuge system should be used for >500KLD STPs.


For <500 KLD STPs, belt press or screw press system should be used.

Same as ASP Same as ASP Same as ASP

3. Mechanical Equipment Requirement for STP

There should be a clear and simple access to the Bar Screen Chamber and Oil and Grease Chamber of STPs introduced. Likewise, the supplies should to be of the submersible sort with a simple removal/it is expected to destroy choice at whatever maintenance is required.

Air blowers of STP should to have Vibration mounts and acoustic fenced-in areas to diminish noise pollution.

4. Location of STP

STP should to be situated under the driveway, play area, or clubhouses, and distant from the residential housings to not make any subtlety individuals living.

Additionally, STP should not be installed in that basement of any structure or building. Admittance to the STP room should to be from Ground Level or Upper Basement through all around designed walkways or headroom, and not from the lowest basement to stay away from subtleties that might occur because of rain flooding, smell or sound.

5. Treated Sewage Standards

The sewage treated should meet the following standards.

S NO. Parameter Required Standards
1 pH 6.5-8.5
2 BOD(5th Day) <10mg/l
3 COD <50mg/l
4 Suspended Solids <10mg/l
5 Ammonical Nitrogen <5mg/l
6 Total Nitrogen <5mg/l
7 Fecal Coliform <100MPN/100ml

6. Guidelines for installing sensors

It’s compulsory to introduce sensors for observing sewage parameters like BOD, COD, TSS, stream, and pH.

The CPCB suggested sensor types with their correspondence conventions are as per the following.

S. No. Parameter Measurement Type Sensor Type Communication Type
1 pH Inline Ion Selective Glass Electrodes RS 485 Communication with Modbus
2 TSS Inline Turbidity to TSS correlation with

Nephelometric technique

RS 485 Communication with Modbus
3 BOD Inline UV-Vis Spectrophotometry

& combustion(Double beam

with entire spectrum scanning

RS 485 Communication with Modbus
4 COD Inline UV-Vis Spectrophotometry

& combustion(Double beam

with entire spectrum scanning

RS 485 Communication with Modbus
5 Flow Inline Electromagnetic Flow Measurement RS 485 Communication with Modbus


7. Caution Board at STP

Legitimate preventative billboards should to be displayed and security conventions should to be followed at the STP locations.

“Danger” Sign Sheets should to be introduced at the STP area for the maintenance personals and general public. What’s more “water not well for drinking” should to likewise be featured at the taps conveying sewage water.

8. Use of Treated Sewage

The treated water should to be compulsorily utilized for toilet flushing purposes that should to have a double pipes system.

9. Modular Operations of STPs

Modern activity of STPs suggests that the STP should to be created/developed in smaller units so it tends to be utilized according to the heap or inhabitance of individuals. In huge tasks where a higher limit of STPs required, the inhabitance in the underlying stages can’t meet the functional measures of the STP Plants. Thus, the component should to be viewed as in the plan stage itself.


November 16, 2022

Reverse Osmosis is a water treatment method that eliminates impurities from water, by applying pressure to drive water molecules through small pores of a semi-permeable membrane.

The impurities are filtered out when the water flows from the, more concentrated side of the RO membrane-which has more impurities, to the less concentrated side-which has fewer contaminants, leaving only clean and worthy drinking water.

Up to 99 percent of 65 distinct pollutants, including lead, fluoride, chlorine, dissolved salts, and more, can be eliminated via the reverse osmosis process. Let’s understand more about how reverse osmosis purifies water!

Components of a reverse osmosis system

The basic components of RO Plant are:

  1. Line of Cold-Water valve

It is a valve that attaches to the supply pipe for cold water. The valve contains a tube that connects to the RO pre filter’s inlet side. The RO system’s water supply comes from this.

  1. Pre-Filters

The Reverse Osmosis Pre Filter receives water from the cold-water supply pipe first. In a Reverse Osmosis system, more than one pre-filter might be employed; the most frequent ones are sediment and carbon filters.

These pre-filters are used to protect the RO membranes by eliminating debris that could block the system, such as sand, silt, and dirt. In addition, chlorine can be eliminated using carbon filters, to prevent damage to the RO membranes.

  1. Reverse osmosis membrane

The system’s heart beat is the reverse osmosis membrane. A wide range of pollutants, including those with an aesthetic or health impact, can be eliminated by the semi-permeable RO membrane.

The water enters a pressurized storage tank where treated water is kept, after passing through the membrane.

  1. Post filter

The treated water travels through a final “post filter” after leaving the RO storage tank, but before reaching the RO faucet. Typically, a carbon filter serves as the post filter. A post-filtration “polishing” filter gets rid of any lingering tastes or aromas, in the product water.

  1. Automatic Shut Off Valve (SOV)

The RO system incorporates an automatic shut off valve for water conservation. The automatic shut off valve closes when the storage tank is full, to prevent any additional water from penetrating the membrane, and to cease flow to the drain.

The shutoff valve opens to allow the drinking water to pass through the membrane, while the polluted wastewater is directed down the drain, as soon as water is drawn from the RO faucet, and the pressure in the tank reduces.

  1. Check valve

The outlet end of the RO membrane houses a check valve. The check valve stops treated water from the RO storage tank from flowing backward. The RO membrane could be ruptured by a backflow.

  1. Flow Restrictor

A flow restrictor controls how much water passes through the RO membrane. The main aim of flow control is to maintain the flow rate, necessary to get drinking water of the highest possible quality (based on the gallon capacity of the membrane).

Additionally, the flow restrictor aids in maintaining pressure on the membrane’s input side.

  1. Storage Tank

The typical RO storage tank has a capacity of 2 to 4 gallons. When the tank is filled, a bladder inside maintains the water pressurised.

  1. Faucet

A faucet is included with the RO unit and is mounted at the kitchen sink. Air gap faucets are required by plumbing codes in some places, however, non-air gap types are more prevalent.

  1. Drain line

This pipe connects the Reverse Osmosis membrane housing’s outlet end to the drain. Wastewater comprising pollutants and impurities that have been removed by the reverse osmosis membrane, is disposed of using drain line tubing.

How reverse osmosis purifies water?

The RO membrane is the essential part of a reverse osmosis system, however, it also has other filters. Every reverse osmosis water system also has a sediment filter and a carbon filter, in addition to the RO membrane.

Depending on whether the filters are used before or after the membrane, the filters are referred to as pre-filters or post-filters.

The Commercial RO Plant process typically has four stages:

  • SEDIMENT FILTER: This pre-filter stage is made to filter out sediment, silt, and dirt. It is crucial because it prevents dirt from reaching to the vulnerable RO membranes, which sediments can damage.
  • CARBON FULTER: It is intended to get rid of chlorine and other impurities that reduce the effectiveness and lifespan of the RO membrane, as well as enhance the flavour and odour of the water.
  • REVERSE OSMOSIS MEMBRANE: The RO system’s semi-permeable RO membrane is made to let water pass through, while removing practically all extra impurities.
  • FILTER FOR POLISHING: A final filter in a four-stage RO system polishes the water to get rid of any last-minute tastes and odours. It ensures that the water will be of the highest quality.


An RO system’s optimal performance depends on high-quality components. This is because, the best-intended results—high-quality water for homes and businesses—are eventually produced by RO units made with excellent craftsmanship, superior materials, and components.

In the last decade, Netsol Water discovered that the most important factor in differentiating between reverse osmosis systems is the quality of the components. Therefore, it becomes our primary responsibility of us to provide the highest quality RO systems, including Commercial RO plants as well as Industrial RO Plants.

For any other support, inquiries, or product purchases, call on +91-9650608473 or email at

November 16, 2022

Reverse osmosis (RO) produces clean, great-tasting water and is widely regarded as one of the most efficient water filtration techniques. Numerous uses for RO systems exist, such as faucets, whole-house, aquariums, and restaurant filtration. Whatever the initial quality of your water, there is probably an RO system that will work for you.

Reverse osmosis: What is it?

When pressure pushes water through a semipermeable membrane, reverse osmosis eliminates pollutants from unfiltered water, or feed water. To produce clean drinking water, water flows from the more concentrated side of the RO membrane—which has more impurities—to the less concentrated side—which has fewer contaminants. The permeate is the name for the produced fresh water. Waste or brine is the term for leftover concentrated water.

Small pores in a semipermeable membrane allow for the passage of water molecules but impede the passage of pollutants. Osmosis involves the concentration of water as it moves through the membrane to achieve equilibrium on both sides. However, reverse osmosis prevents pollutants from passing through the membrane’s less concentrated side.

Let’s use what we now know about reverse osmosis to analyze a real operational plant. 

The entire reverse osmosis procedure, including the pretreatment and post-treatment that are typically necessary for heavily contaminated water, is described as follows:

  1. Pre-chlorination dosing system:

The media filter will be able to filter the majority of it if the supply water is contaminated or includes traces of heavy metals. It is strongly advised to dose some chlorine to convert the dissolved heavy metals to physical form.

  1. Tank for storing raw water:

Most reverse osmosis systems begin with a sizable tank that holds the polluted water, while some RO Systems can draw water directly from a well or pipe feed. Having a large storage tank for your intake water is an easy approach to ensure that your pump lasts as long as possible. Not having enough feed water can harm a pump.

  1. Feed Water Pump:

The treatment system receives its initial pressure from a commercial or industrial pump. The RO membranes and any pretreatment are often passed through this motor’s sufficient water pressure, but if they aren’t, a booster pump may be required later on.

  1. Media or Multi-Layer Filter:

Even while we hate to acknowledge it, some items can’t be purified by membranes. Reverse osmosis is unable to remove particles that dissolve too well in water, such as nitrates, a frequent pollutant present in fertilizers and animal manure. Reverse osmosis typically doesn’t work to eliminate things like bad taste and odor. Media that especially targets the items your RO system can’t catch can be put in a multi-layer filter. A multi-layer filter is necessary if these pollutants are to be removed.

  1. Filter with activated carbon:

To eliminate organic contaminants, unpleasant tastes and odors, and chlorine from the water, activated carbon filters are a suitable option.

  1. Chemical dosing system for anti-scalant:

We employ anti-scalant dosing systems to provide our anti-scalant RO chemical, which aids in preventing membrane fouling.

  1. System for Reverse Osmosis:

We have our reverse osmosis system at last. A booster pump will normally be required right before this phase, if at all. The reverse osmosis system can generate a significant amount of waste and up to one million gallons of product water per day from a continuous inflow. Although it can typically be poured down the drain, check with your local water authority to see whether special handling is required.

  1. Storage tank for product water

The reverse osmosis system’s permeate often drains into a sizable tank where it is stored until needed. If it didn’t, it would be necessary for the system to be on in order to have access to fresh water, which is sometimes problematic. In addition to being utilized in many of the typical industries or applications, an RO system may also be used to pump water straight into a well or aquifer for recharge.

  1. System for Post-Chlorination Dosing:

It is strongly advised to inject some chlorine into the permeate water if it will be kept for more than a day in order to keep it clean and free of contaminants.

  1. Water Pump:

The permeate water is repressurized by this pump until it is no longer usable. This is chosen based on the required head and overall distance to travel. The permeate water must not be contaminated, hence stainless steel must be chosen for this pump.

  1. UV Sterilizer for product water:

The UV sterilizer is used as the last line of defense against infection after the storage tank. Most of the time, we either employ UV sterilization or post chlorination as a disinfection agent.

How Netsol helps!

We offer a wide choice of reverse osmosis and water treatment systems to fit your demands. Netsol has years of experience as a global provider of water treatment solutions for a number of applications and industries. Our ability to pre-engineer and modify water treatment and reverse osmosis systems to match a variety of customer requirements and specifications is made possible by Netsol’s significant global experience in engineering and manufacturing.

For any support of inquiries, or product purchases and related services call on +91-9650608473 or email at



November 15, 2022

What are benefits of sewage treatment plants?

To enhance the quality of wastewater for recycling, sewage treatment plants use primary, secondary, biological, and tertiary treatment processes. Wastewater is produced as a result of expanding infrastructure development and increased water use for home and commercial needs. A sewage treatment plant’s main objective is to treat wastewater as fully as is reasonably practicable. Sewage treatment facilities and other options can help with that. A sewage treatment plant may be put practically anywhere as long as there is an electrical connection, thanks to the way they work.

The need for clear water is in itself a proper justification for the sewage treatment plants in the vicinity of human-held areas. When we say that sewage treatment plant saves water, we mean that it saves life and what could be the greater benefit of sewage treatment plant then?

For a better understanding of the benefits related to sewage treatment plants let’s go deeper!

Benefits of sewage treatment plants

Having a contemporary sewage treatment system has several advantages.


Sewage was traditionally manually removed and collected. Modern technology allows for the extraction, organization, and transportation of sewage, all of which require a minimum number of employees. Modern sewage treatment facilities can also handle enormous volumes of sewage, which cuts down on lengthy workdays.

Create Energy

Significant amounts of the organic materials found in sewage can be utilized to produce electricity. After being pre-treated, sludge is broken down via anaerobic digestion. Methane gas generated by anaerobic digestion powers the grid. Both the sewage treatment plant and the residential areas’ electricity needs may be met by it. Additionally, sewage gas may be set up as a combined heat and power plant (CHP), which boosts the plant’s overall effectiveness.

Fertilizer Manufacturing

Massive amounts of nitrogen, phosphorus and biodegradable material are present in the sludge that is collected for treatment. As a result, the sludge drying procedure produces biodegradable fertilizer when applied to sludge. This fertilizer is appropriate for use in farming and gardening.

lowered danger to public health

Only 50% of Indians have access to clean drinking water, and each year 37.7 million Indians get ailments brought on by contaminated water. Additionally, the disadvantaged Indian community is negatively impacted by the flow of untreated sewage into ponds, lakes, and rivers. Because sewage treatment eliminates the majority of toxins from wastewater before releasing it into natural water streams, it lowers the danger to people’s health.

Environmentally friendly

Environmentally friendly sewage treatment facilities purify water in a number of phases to get rid of germs, pollutants, and big solid particles. This reduces water consumption and pollutants while making the treated water suitable for reuse.


It is crucial to have a working wastewater treatment system because it may stop the spread of illness, save the environment, and ultimately save your money. Additionally, investing in a sewage treatment system is now more financially practical because to technological advancements that make current systems cheaper, more efficient, and simpler to operate than earlier ones. The advantages mentioned above are only a few of the numerous factors that may make purchasing a sewage treatment system a very wise and successful choice.

We at Netsol have extensive expertise in treating and maintaining wastewater systems. Contact us if you have any questions or concerns about your wastewater or water treatment systems.

You can contact us at +91-9650608473 or email at

November 15, 2022

The biggest factor affecting human health and the ecosystem is the untreated direct discharge of sewage into natural resources. Waste produced by residential, commercial, institutional,  and industrial facilities is referred to as sewage. Organic and inorganic pollutants are frequently present in large amounts in sewage. Prior to entering any aquatic body, sewage must be treated. It is crucial to correctly treat sewage before putting it into rivers or any other sources of water because if sewage is allowed to enter them without being treated, it will contaminate them.

Sewage treatment plants come to rescue, to lessen the toxicity of sewage, maintain a safe and healthy environment, and advance human welfare, sewage treatment is essential.

Stages in a sewage treatment plant:

A sewage treatment plant (STP) with three stages—primary/preliminary, secondary, and tertiary—can be designed to treat sewage.

1_Primary Treatment:

In the first stage of treatment, wastewater is sent through a screen to catch any big floating debris. Following this, the water enters a chamber that removes grit ( gravel, Sand, eggshells, seeds, bone fragments, and other things are all considered to be grit). To lessen the amount of heavy deposits in the digester, channels, and conduits, grit removal is required. Primary settling tanks are the next stage. These tanks are often rather big, and the solids fall to the bottom by gravity and are removed as sludge. Oil floats to the surface and is skimmed off in the meanwhile. A 30–40% decrease in the biological oxygen requirement over the course of five days may be anticipated as 50–60% of the suspended solids are eliminated.

2_Secondary Treatment:

The second stage of wastewater treatment is secondary treatment. Oil, grease, and colloidal particles are eliminated during basic treatment. The wastewater is then given a second biological treatment to get rid of any organic debris that is still present.

Local and aquatic bacteria and protozoa that devour biodegradable soluble pollutants including sugar, fat, detergent, and food waste carry out this treatment. These mechanisms are temperature-sensitive, and biological responses accelerate as the temperature rises.

Two distinct treatment steps comprise secondary therapy:

  1. Aerobic Treatment _ Aerobic wastewater treatment is a biological process that breaks down organic debris and removes additional contaminants like nitrogen and phosphorus by using oxygen. Aerobic treatment is typically used in the treatment of sewage.
  2. Anaerobic Treatment­_ Wastewater or other materials are broken down by microorganisms during anaerobic treatment without the help of dissolved oxygen. However, anaerobic bacteria may and will utilise the oxygen present in the system’s supplied oxides as well as the organic matter in the effluent.

3_Tertiary Treatment:

The third step of wastewater treatment, tertiary treatment, is also referred to as an advanced treatment. The nitrogen and phosphorus burden in the water is reduced during tertiary treatment. It involves procedures including electrodialysis, nitrification, denitrification, ion exchange, activated carbon adsorption, and filtering.

The effluent properties following secondary treatment and the kind of water required following treatment determine the tertiary treatment alternatives. For instance, filtration and disinfection are used to treat wastewater if we require drinkable water.


Even while water surrounds 70% of the world, just 2.5% of it is fresh water. On Antarctica and Greenland, 70% of the fresh water is frozen. Only a little more than 1% of fresh water can be used. If we can reuse water for uses other than drinking, such as washing, bathing, and using the toilet, we can reduce the need for fresh water. Therefore, it is crucial to treat every building’s sewage outflow and repurpose treated water for laundry, bathroom cleaning, and floor maintenance.

Netsol provides you the much-needed assistance perfectly when it comes to play the role of hero in saving environment. We can deliver the best services related to STP or water treatment plants.

For any sort of assistance or queries, place a call on +91-9650608473 or email at


November 15, 2022

The main objective of sewage treatment is to create wastewater that can be released into the environment, with the least amount of water contamination feasible, or to create an effluent that can be reused in a beneficial way.

This is accomplished by taking out the toxins from the sewage, as it helps in reducing the risk of water pollution from sewage discharges. As human beings, it is our duty to protect the environment. As a result, we can opt for chemical-free, environmentally friendly sewage treatment technologies. Therefore, before making a purchase of sewage treatment plants, take into account the carbon footprint, energy use, and chemical use as well.

Thus, it is essential to choose a reputable sewage treatment plant manufacturers, so that all the requirements are met.

Why do sewage treatment facilities need to exist?


India is regarded as the land of irrigation. Although, the land generates an abundance of crops, the nation struggles with drought. Deficits are primarily caused by leaving a large amount of wastewater untreated. Because, untreated water cannot be used to irrigate crops, it causes a water shortage. Therefore, treating wastewater is important for water-stressed nations, such as India.


Residential, industrial, and commercial areas also generate a large volume of wastewater, which can be treated and reused.


STPs with exceptional features


Sewage treatment plants with exceptional features are provided by Netsol Water Solutions.

These are listed below:


  • Electric/Non-Electric


Netsol Water Solutions provide both electric and non-electric sewage treatment plant systems. However, it is advisable to choose a non-electrical solution if residing somewhere that does not have electricity constantly, or that has regular power interruptions.


If one wants to cut down on electricity usage, this is a wonderful alternative. At a reasonable cost, there is the choice to have a solid sewage treatment system.



  • Noise and odour


Netsol Water Solutions provides a sewage treatment plant that emits less noise, and no offensive odours. Particularly, if we intend to install it in a residential area, both considerations are crucial.


In order to improve the working environment in our commercial or industrial location, we must also pay attention to this.


Why must you choose a reputable sewage treatment plants manufacturer?


Some suggestions for picking a reputable sewage treatment company are as follows:


  1. Be aware of the possibilities; the value and cost will depend on the demands.


Educating oneself is the first tip for picking a sewage treatment company. Selecting a sewage treatment plant manufacturer may seem like a straightforward process, but as a customer we should make sure that, we have the knowledge of what we are buying.


We should educate ourselves by responding to the following questions in advance.


  • Recognize the machinery that need repair.
  • Recognize the treatment recommendations made by the manufacturer.
  • Learn the equipment’s specifications.
  • Cost of not running the equipment for your company.


  1. Business integrity.


Understanding how a company’s staffs interact is typically an excellent method to judge a business. Small observations can be significant early warning signs of future issues, with that manufacturing company.


  1. Know the dangers present.


Both actions—doing and not doing—involve dangers.


What are the risks of doing nothing, for example, if the equipment breaks, how much would it cost the company if that were to happen? What are the potential financial costs involved in doing so, and how will it impact the operations of the company?


All these factors should be kept in mind.


  1. Which service level (excellent, better, best) do you require?


If the system isn’t directly correlated with the success of a firm, good may be sufficient. If it is more directly related, one might want to think about spending extra to have higher levels of service, to make sure there is as little downtime as possible.


  1. Once it has been established what each company claims to be unique in, hold them to that standard.


Making a purchase will be simpler if you know what makes a firm unique, and you’ll be able to hold the provider to the same standards, they’re claiming.


We see clients all too frequently who claim to have not seen their current vendor in months, despite the fact that monthly visits are supposed to take place. Make sure you and the manufacturer have a clear understanding of their deliverables up front, and that you hold them to that standard.


Best manufacturers and service providers of sewage treatment plants in India


Finding the best sewage treatment plant for your needs can be challenging, but a straightforward answer is provided by Netsol. The idea that “one size fits all” does not apply to treatment systems at NETSOL WATER SOLUTIONS, since we think that every customer has different needs.


For any other support, inquiries, or product purchases, call on +91-9650608473 or email at


Greater Noida


We are the leading Sewage Treatment Plant (STP) Manufacturer & Supplier, in the Delhi-Noida, India.
+ 91-9650608473


We Are Everywhere in India & Overseas.


Follow Our Activity

TO get an update about our daily activity just follow us and Join the Hands to Save Mother-Earth