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.