How do Sewage Treatment Plants Work? | Chokhavatia Associates

The importance of sewage treatment plant design is to withhold all the solids as much as possible and before the leaving water called an effluent is discharged to the environment. The solid matter decays it uses oxygen that are needed by the water plants and animals.

Water Recycle 

With the ongoing water scarcity in cities and towns the only way ahead to treat the sewage water by sewage treatment  plant so that the non-hazardous water can be reused to increase the surface water or recharge the ground table water.

How does a Sewage Treatment Plant Work?

Sewage Treatment works in four different methods first the waste goes through the initial process called the preliminary method where most of the course solids are removed. This process includes large filtering READ MORE.....

Why Industries Using Sewage Treatment Plants for Removing Pollutants ? | Chokhavatia Associates

In order to free the water consumed for irrigation or drinking and even household purposes from all sorts of harmful contaminants, Sewage Treatment Plant plays a quite crucial phenomenon. The containments present in the waste water should be significantly decreased by getting rid of bacteria, suspended solids and all other organic wastes as well as chemicals that make the water polluted so that can be reused again.

Sewage Treatments denotes domestic wastewater management and seeks removal of pollutants from household sewage that consists of domestic and runoff. On an average, environmental engineers are accountable for designing and erecting facilities where wastewater is to be treated. There are various ways and means as physical, chemical besides biological approaches through which wastewater can be treated and is sent back to the environment so that it can be reused.

The most accepted Sewage Treatment Plant that is usually set up for treating sewage embraces three stages-i.e. entire procedure has to undergo primary, secondary &tertiary stage of treatment. In the very first step solids are mined out from the waste water and it is through usage of home cultivated water borne micro-organisms dissolved matter is transformed into solid masses. Residues remained are there after nullified and then after thrown away or re-used.  Thus, the water gets disinfected either physically or chemically with the support of lagoons or microfiltration.

In the end, the water that has been treated is now discharged into either river, stream, wetland or either it can be reused for irrigating farms.

The treatment plant developed for cleaning sewage works to eradicate suspended solids in addition to bio chemical oxygen demanding waste also known as BOD as this helps to reduce fish kill, as of diminishing oxygen levels that can leave adverse effects on marine life.  Diverse forms of treatment are as follows.

1. Primary Treatment

In this phase substances that can be removed effortlessly from waste water are eradicated as oil /fat/ racks and even trash..

2. Secondary Treatment 

This procedure cuts down the biological toxins that are present inside the sewage. At this juncture micro-organism are assisted to eliminate the undesirable elements present in the sewage.

3. Tertiary Treatment

This step emphasises on the betterment of the quality of the water, prior to sending back to the environment for usage for all purposes. This can be accomplished either by treating it by artificial filters or by natural filters like marshlands and even lagoons. With the help of treatment excess phosphorus and nitrogen can be removed.

For total removal of microrganism, a treatment plants have to often take a treatment of chlorination prior to release of treated waste water. Ultimately this chlorine is being eliminated from water after being chemically treated by sulphur di oxide reaction; and this helps in making water safe for the life that is dependent on it.

At last, this treated water is released in river, ponds lakes or even sea whatever is the closest destination. There are lots of services providers who provide solutions to fix drainage problems in a very cost effective manner.

Chokhavatia Associates have put up more than 37 years of experience with a global client base. Our services in environmental sector include concept to commissioning of Wastewater Treatment Plants for the industries and sewage treatment plants.

Wastewater Treatment as in Sewage Treatment | Chokhavatia Associates

Wastewater treatment is cover under sewage treatment because in wastewater we purify wastewater as in Sewage contains human and animal waste and pollutants ,effluent. Sometime it contains storm water also.

Wastewater disposed as municipal or commercial wastes and be treated under sewage treatment plants. Wastewater contains both residential and industrial waste to treat. Differentiating solid and liquid waste from the sewage and treat the remaining liquid and make it safe for surroundings and reusable is called “Wastewater treatment” . In wastewater there are three processes called 1) Chemical, 2) Physical and 3) Biological. Considering which type of effluents are in wastewater, process can be apply .

As above wastewater contains Residential waste as well as Industrial waste.

Residential waste is like municipal sewage, remaining waste of house holds, sludge coming from dirty area etc. It contains only grey water .To treat this needs low rate treatment. It tends to be lower in coast and less maintenance. For this We just required physical and biological process. Filtration and clarification which are in physical process of wastewater treatment, can use for this type of wastewater.

Industrial waste contains effluents coming from industry, chemical sludge ,Toxins coming from pharmaceuticals .It contains black water. It is high rate treatment contains high cost and high maintenance. It requires pretreatment which is not full treatment in industry just remove pollutants before it discharge from industry. Pretreatment consist physical process, and for removal of effluents and toxin , Chemical and Biological process apply. For Biological process biological treatment units are use this process is called Activated sludge process.

As above there are three basic processes in wastewater treatment which are describe below:-

 Physical Process:-

Removal of physical substance from the sludge called physical process. It involves filtration, clarification ,sedimentation and aeration. Now Removal of solids settles which are in base is called Sedimentation .Whenever heavy solids go at the bottom, to discard them from wastewater become easy. To increase oxygen in the remaining waste and contaminated water is called Aeration. Passing water through filters and separate solid and liquid part of waste is called Filtration. These all processes are done by physically so its called Physical Process.

It is used in mostly residential area and also in Municipal sewage.

Chemical Process:-

Taking out the existence of contaminants from the wastewater is called Chemical Process. To purify water ,most used treatment is considered to be chlorination. To decompose water and remove bacteria from the waste water, chlorine is most usable chemical. It is a strong oxidizing chemical. By the oxidation we can purify water and make it reusable by controlling the bacteria growth, and for that we can also use agent like ozone.

It is widely use in industrial area and some times it is used in municipal sewage also. In industry PH control and neutralization is also necessary. Carbon is use for this process because of its adsorption property.

Biological Process:-

Making wastewater biochemically decomposed and stabilizing it called Biological Process. This process makes use of bacteria and other microorganisms which are in waste water. It categories in Aerobic and Anaerobic. An aerobic process we have oxygen presence ,and by the bacteria it transform in to CO2.In anaerobic process the sludge is fermented in considered temperature without O2.

Frequently Asked Questions About Sewage Treatment | Chokhavatia Associates

People have many question about Sewage treatment and its plant ,because they don’t have total knowledge about this and you never know when you might have to deal with this treatment in future. There are some FAQs given below which often discuss.

1.What is the major difference between Sewage treatment plant, septic tank and CESS pit? What can I use septic tank or sewage treatment plant? 

->There are three types of treatment system in use: Sewage Treatment Plant:-Higher level of treatment than septic tanks and provides Consent of Discharge is in place. Purified water is reusable .Modern Plants are preferred for this treatment. Septic Tank:-It provides minimum treatment. It is a system that flows effluents out and retained solid waste in tank, until not doing the tank empty. It clears water from chemical effluents and makes better environment and water also. It is used for small domestic developments. Cess Pit:-It is also called Cesspools.

It simply holds tank which is emptied by tanker basically. There is no treatment in this. It has large structure and not suitable due to operating cost. It is the least useful plant. 

2.What is the custom designed plants of sewage treatment?

 ->The plants which are design as we want ,they don’t have particular plant pattern called custom designed plants. If we want purified water we make wastewater treatment plant, sometime biological treatment plants are useful. Many Eco water systems make their own sewage treatment plants. 

 3.Why my Sewage treatment plant is smell? Is there any issue about it?

 ->Sometimes the arrangement goes improper ,and it is a septic tank ,it has drain pipes. The pipes must be sealed and connected to correct location. Disposal of Septic tanks must have right intervals. How to forget it is a biological aeration plant, so it integrates an aeration process. So if smell detect than go through the manufacturer’s guidance. 

4.What is “Consent to Discharge”? and how long does it take to get it?In India is there any legal document ? 

-> Consent to Discharge is a legal document or No objection certificate which is provided by local environmental agency. They have authority to measure parameters of treated sewage which satisfy their rules and reuse water to other system.

->They set specific time period for particular sewage treatment plant by its performance.

 ->In India individual homes are not require NOC or CTD. But Industries and other organization require legal document for further process. 

 5.What is BOD5?

BOD means “Biological Oxygen Demand”, and ‘5’ stands for 5 days long test to carry out. First of all it measures the pollutant’s strength and organic value of an effluent. Then after it goes for incubation and measuring oxygen level. The sample is incubated at 20̊C for 5 days. This process is done many times until oxygen level is not set. It represents microorganisms’ level of activity which are present in the effluent. The activity level should match the level of pollutant’s strength and organic value of an effluent. So it is directly proportional to each other. In some process oxygen will be depleted if an effluent is strong for aquatic environment.

These are some FAQs related to Sewage Treatment Plant .Hope these are useful.

Sewage Treatment Plant’s Design- Workflow- Significance

The pace of industrialization is exponential that the adverse effect caused by it is contributing to the environmental concerns. Though people are aware of the limitations in water resources, water pollution still prevails. Thousands of gallons of sewage water are being released everyday by numerous factories and industries which adds to the pollution of both land and water sources. Sewage treatment plants do the work of removing the contaminants from sewage water before it getting expelled into environment.

Work Flow and Sewage treatment plant Design

Sewage treatment plant design are simple in their built up and working procedures. The various stages in the sewage treatment have the following process involved in it.

Primary Stage/Sedimentation

The primary stage happens in huge tanks which involves sedimentation of heavy solid waste while liquid impurities like grease, oil floats to the surface. The liquid impurities are then separated from the solid waste by clarifiers and the process is known as clarification.

Secondary Stage/Aeration

Aeration is the part of secondary stage of sewage treatment. It involves the process of sludge activation which is done by pumping air into the tank using large sized fans called aerators. The impure organic contamination in the sewage water has a very high demand for biological oxygen and aeration provides oxygen to bacteria for treating the wastewater. The bacteria help in gathering sludge impurities and it is removed. The aeration tank design and the process of aeration have a direct impact in the efficiency of sewage treatment plant.

Tertiary stage/Disinfection

The tertiary stage in the sewage treatment plant is the disinfection process. The treated sewage water from the earlier stages is disinfected either chemically or physically to remove the toxic contents and thus making it fit to discharge into the local water bodies.

Significance of Sewage treatment plants

Sewage treatment plants play significant part in controlling the water pollution. The contaminated water which is drained makes an imbalance in the aquatic ecosystem and when the untreated water is used for irrigational purposes the fertility of the land is completely lost. The major reason behind the life crisis in some of the underdeveloped countries is because of the absence of proper sewage treatment systems making the state of life miserable.

Maintenance of Sewage treatment plants

As sewage treatment plants functions round the calendar the maintenance schedule of the treatment plant should be strict. The energy should be efficiently used and knowledge about the various machines involved in the treatment process is vital. The machineries like clarifiers and aerators are the most integral part in the treatment process and hence there should be regular inspection in their working condition. There should be no compromise in the quality and maintenance procedures of the machinery used in process as it may lead to lack of efficient functioning. The clarifiers should not get clogged with the solid impurities and the filaments in aeration tanks must be cleaned regularly from the biological built up which not only increases its energy consumption but also reduces the efficiency rates. The aerators should be cleaned from biological growth as it may lead to improper sludge deposition.

Sewage Water Treatment Process | Chokhavatia Associates

Sewage water needs to be treated in the sewage plant before it can be drained into the environment. Careful measures need to be taken. If not, it can lead to harmful effects in the environment. Health issues, water pollution are some of the problems that are caused by the sewage water if not treated properly.

The sewage is the waste water that is collected from wash basins, toilets, baths, washing machines and industrial waste. They are treated through a series of steps until it’s treated and finally drained back into environment when it’s considered to be safe.

Screening

Screening is the initial process in sewage water treatment. The sewage system makes use of the septic tank that collects and stores the sewage water. The solids settle down and the remaining water is sent downstream for processing through 6 inch to 4 inch pipeline. Such a process is called a decentralized system where every house’s sewage is treated in separate septic tanks.

During the screening process, large objects like diapers, tampons, sanitary items, face wipes, plastics and rags are removed to prevent from any blockage in the downstream to the sewage plant. Items like grit are removed using special equipment that gets washed away into the sewer.

The sewage water treatment can use the gravitational force to get to the sewage treatment plant. In-case if the pipeline excavation is not possible due to hard rocks or any other reason, the sewage water need to be pumped into the pipeline right to the sewage treatment plant. The pipeline measurements range from 6 inches up-to 30 feet of well built concrete tunnels.

Primary Treatment

During the primary treatment, solid waste (human waste) is separated from the waste water and sent to be treated. The wastewater is collected in large settlement tanks, where the solid waste gets settled leaving the water on the surface level. There is also fat that rises to the top and form a crust. The liquid in-between the solids and crust is sent to secondary treatment whereas the solids and the top layer of crust are sent for further treatment periodically.

Secondary Treatment

The water from the primary treatment is placed on large rectangular tanks. Now, oxygen is supplied into this process to encourage the growth of bacteria. The bacteria break the tiny bits of sludge that might have escaped during the previous treatment. It also reduces other pollutant and detergents that might still be mixed with the waste water.

Final Treatment

In this process, the waste water is passed into a settlement tank. Excess sludge is formed again due to the bacterial action. This sludge is repeatedly scraped to remove from the water. Once the sludge is removed, the water is free from pollutants. The water at this stage is completely free from any kind of harmful physical or chemical substance, and it is free to be drained into the river.

The waste water goes through several stages in the sewage treatment plant to make it safe for the environment. The water is thoroughly treated until they make sure that it is clean and pollutant-free before discharging it to the water bodies. One more important factor for screening the sewage water is to prevent any diseases that may be caused due to bacteria, virus or any organisms.

Sewage Treatment Plant Helping In Tons of Issues

Sewage Treatment Plants acts as the dumping ground and treatment facility of the wastewater for the discarded waste amassed from the residential areas, industrial setups, establishments and also from agricultural lands. The gathering and clutter of sewage systems dispatches the wastewater all through the way from cities to the site of treatment plants. The wastage is treated in these facilities so that the water pollution is controlled as a result natural environment is been preserved.  This process makes sure that before discharging to the environment in particular to the water bodies, the treated water is thoroughly clean and exempted from all sorts of containments. An added objective of treating wastewater is preventing from spreading of any epidemic due to it, and arranging a protection blanket to public health.

With the help of gravitational forces, the sewage system transports the wastewater, so that it is diverted to treatment plant.  If due to boulders of rocks, there is difficulty in excavation, sewage must be pumped, so that the wastage directly reaches its destination.  We have to find ways to find solution to overcome topographic hurdles; and experts of this field are always there to help us put in finding such ways.   Sewage pipes lying in low line areas, provisions are made to dispose of waste through vacuum.  With limited topography available, gravitational influence might not be applicable. 

STEP System also known as Septic Tank Effluent Pumping collects sewage from community or rural or townships where advanced and well planned network of sewage systems do not exist. The number of residents serve up in deciding the size and design of Septic tank and even sewage system.

Another factor that is considered while deciding the size and shape of a treatment plant is keeping in mind the   flow and type of commercial and industrial wastes. The merged sewer approaches, are built to transmit sewage and storm water runoffs together at the similar time and that too in similar pipes. The traits of the watershed are as well kept in account when the project design for merged sewer system is been developed by experts.

Now days, the style and strategy of sewer lines that moves to the treatment plants nowadays are designed in a manner that one can find separate lines for storm run-off and sewage. The storm runoff moves right to the surface water, whereas, contaminated and waste in form of sewage is transported to treatment plants specifically designed for it.  Even though, in modern setup the design system does have separate lines are been designed and constructed, there are situations when inflow and infiltration of surface water in sewage pipe lines cannot be prevented.  This in fact, may cause over flow of sanitary sewer.

Generally, there are a stack of issues related with sewage system that can be performed, it is environmentalist who through his knack can deliver number of solutions. As an entrepreneur you have to open yourself in front   of a service provider