Sewage Management Methods

Sewage management is basically the process by which the waste is treated for the advantage of man. There are different processes involved in sewage treatment; they are the sewage, treating and screening of the sewage. This also involves disposing of the sewage in such a way that it does not cause any hazard or harm to nature and the health of humans also. In this article, you are going to get a brief knowledge about sewage management and why it is necessary to perform sewage management.

Methods

As you know, waste generation is one of the most inescapable and natural activities of the human lifestyle. For the existence of humans, water is compulsory to perform various activities. These life processes include domestic works, industrial manufacturing, services like railways, restaurants, etc. All these usages generate a large amount of wastewater. Even though the natural water reservoir replenishes periodically, the resource is not unlimited. As the human population is increasing day by day so is the use of the water for various domestic work is increasing, so in order to protect this water for our future generations it is necessary that you reuse the water that you have wasted so that the resources may not replenish away till our future generation comes and we cannot even imagine our life without water and other natural resources as we are completely dependent upon these resources.

Thus, for protecting our environment, we use these sewage management methods by recycling the used wastewater because it is necessary for the present and next generations. If this misuse of water resources continues, adverse situations such as scarcity or drought are inevitable in the upcoming days.

To prevent this type of pollution, you need to learn about the systematic methods of sewage treatment. Here in this article, you are going to get brief information about sewage management that will help you to protect the water and environment from getting polluted.

Definition of Sewage Treatment

Sewage treatment suggests a process that can eliminate impurities from household sewage and industrial wastewater. Majorly, four methods of sewage water treatment are followed – physical, biological, chemical, and sludge water treatment. By following these methods, the wastewater is disinfected from all the sewage materials and converted into treated water that is safe for both human usage and the environment.

Talking about basic sewage treatment methods that is

Physical Method: This is basically the process of removal of small and large floating and suspended solids from sewage through two processes of sedimentation and filtration.

Firstly, the suspended particles or floating particles are removed by filtration. The filtration is then kept in large open tanks where the suspended impurities are allowed to settle down.

Biological Method: In this method, the human waste or other degrading wastes are treated by the bacteria and microbes that convert the sewage waste into byproducts such as sludge.

Chemical Method: In this method, chemicals are used in wastewater treatment. For this, chemicals are used to sterilise the wastewater so that it does not transmit any kind of infection.

Activated Sludge Method: Activated sludge method uses microorganisms to feed on the organic components of the wastewater. This process, in turn, produces a purified effluent. This solution is injected and supplied with a large amount of air to meet the oxygen demand of the microorganisms.

This entire containment removal process occurs before this impure used water reaches the natural water bodies such as lakes, rivers, oceans, and estuaries. As the availability of pure water is scarce, the difference between clean and polluted water is completely based on impurity concentration and intent of usage. 

In other words, water is considered polluted when it is not fit for any specific purpose like drinking, fishing, swimming, etc. Water contaminations primarily happen due to the drainage of impure wastewater into groundwater or surface water. And different sewage management methods can prevent water pollution significantly. And the water that is safe for drinking and other domestic uses as well as for swimming, fishing etc., is considered as non-polluted water or water that is safe for drinking.

However, before a discussion about these methods, you should know about the principal pollutants and sewage types first.

Types of Wastewater

Typically, three types of sewage are there-

• Domestic Sewage

Domestic wastewater includes the used water from apartments or households. This type of wastewater is also known as sanitary sewage. It can be the water that runs down from the shower or body waste as well. This wastewater is generated by our homes daily due to daily household activities.

• Industrial Wastewater

Industrial wastewater carries contaminated water from chemical or manufacturing processes. Various pollutant chemicals can be present in this sewage. As this wastewater mainly comes from industries, it can be toxic and contaminated with heavy metals.

• Storm Sewage

Stormwater implies the runoff sewage that comes from the atmosphere in the form of water particles collected in open channels. This can include rain, drizzle, snow, etc. Above 99.9% of the entire wastewater comes from domestic sewage. Even though the principal contaminants are described as plant nutrients and organic materials, domestic wastewater also contains harmful microbes. This wastewater contains the nutrients that can be collected after sewage treatment.

 Major Pollutants

• Organic Substances

The quantity of perishable or biodegradable organic materials in wastewater is calculated by BOD or biochemical oxygen demand. BOD is the oxygen amount required by microbes to decompose these organic substances in wastewater. It is one of the most vital criteria for the operation and design of sewage management methods. 

• Suspended Solids

Suspended solids are another crucial element of sewage. The amount of sludge generated in a water treatment plant depends on the entire suspended solids included in the wastewater. Storm and industrial sewage carry a larger volume of suspended solids than domestic wastewater. 

• Plant Nutrients

Primarily, domestic wastewater carries chemical elements like phosphorus and nitrogen, which are the fundamental nutrients for plants’ growth. If these elements are excessively present in surrounding water bodies like lakes, it can boost the growth of algae. This may accelerate the natural ageing of these water bodies.

• Microbes

Moreover, domestic wastewater also carries various microbes that come from the intestinal tract of humans. Coliform bacteria are found in high concentrations. In present days, an excessive coliform count has been observed in sewage pollution.

By sewage treatment methods, these pollutants are removed from the sewage water so that it can be reused.

Sewage Treatment Methods

By employing various wastewater treatment methods, contaminants like chemicals and sewage can be eliminated from wastewater and recycled for further usages. Mostly, there are four methods of sewage treatment that are listed below in tabular format with important points-

Disposal Methods of Sewage

Sewage disposal methods are the basic components of a sewage management system. It disposes the used water from households, factories, etc. and helps to keep the environment clean. Following are some well-known sewage disposal methods practised around the globe.

• Municipality Systems

In the municipal wastewater system, there is a treatment plant connected to the source of wastewater. By treating the used water, this plant efficiently removes near about 95% of impurities. Then, by an anaerobic process, the sludge is again treated to ensure the safety of using this water.

• Off-Site Sewage System

Due to the increasing urbanisation, the off-site sewage system has resulted. In urban areas, the houses are built on plots, and each plot is connected to a wastewater line. These wastewater lines collect waste from various households and flow towards a community sewage treatment plant. Here, excess water is directed towards a nearby river or irrigation area once the treatment is done. On-Site Sewage SystemAnother name of the on-site sewage system is a septic system. This disposal system is composed of a septic tank where the sewage can be settled, treated and similarly slurred on the same place of waste generation. In this process, the wastewater is disposed of and treated in natural ways. Usually, an on-site system comprises a septic tank and disposal field that is the soil absorption place. The wastewater slurry is carried out to this leach field, where microorganisms can decompose it over a period. These sewage disposal methods are reliable, hygienic, economical, and efficient.

•  Full Wastewater System

In a full wastewater disposal system, the sewage water is collected from households and then directed to various sewer pipes. During this process, all solid wastes go through multiple sharp blades or macerators. It helps to decrease the dimension of solid waste before further processing.

• Lagoons

Lagoons signify large open ponds that can collect wastewater from households. These water bodies contain a large number of microorganisms that decompose the waste. Sunlight and wind act as catalysts in this process by accelerating the decomposition process. Moreover, algae also assist in the breeding process of bacteria in waste. Due to the presence of algae, these lagoons appear greenish.

• Pit Latrines

Pit latrines are the century-old sewage disposal method found in human civilisation. In present days, these are found in rare places with restricted water supply. This disposal system includes a borehole, trench latrines, and ventilated improved pit. Shallow trench latrines are used by large gatherings for a shorter time and once they are nearly full, closed with soil.

Methods of Sewage Collection

A sewage system is typically designed by various underground channels to carry wastewater discharged by localities. The collection system is configured with pipes, manhole drains, holding basins, catch basins, inlets, and pimp stations that can move sewage from the collection point to discharge. The pipe systems and other appurtenances are primary methods of sewage collection in urban places.

• Combined System

A combined collection system carries both storm and domestic wastewater. This collection system is typically constructed with pipelines or tunnels of wide diameter. However, in rainy seasons, this system sometimes fails as water treatment plants cannot treat a heavy volume of storm sewage.

• Separate System

In relatively newer cities, separate wastewater systems that carry domestic and storm wastewater separately are found. The surface runoff sewage or stormwater is disposed of in open water streams like a river. Smallholding basins or catch basins can be installed for heavy water flow during wet seasons. However, domestic wastewater is directed to a treatment plant. From the in-detailed discussion about methods of sewage treatment, you have understood the treatment process, collection process, and disposal methods. 

You can also check our online classes on the Vedantu website for other chemistry chapters. For a further note on sewage management methods, you can now download our Vedantu app too. Vedantu will provide you with detailed information of all the chapters that will not only increase your knowledge but also will help you to score well in your examination.