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Last updated date: 18th Jul 2024
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An Introduction to Sewage

Prior to the late 1800s, the majority of the population practised open defecation and the outdoor toilet was the primary method of disposing of human waste. After Louis Pasteur and other researchers demonstrated that sewage-borne germs were to blame for a number of infectious diseases, sewage treatment plants were put in place in urban areas. Initial efforts to cure sewage water in the 1900s typically involved buying huge farms and dispersing the waste across the field, where it decomposed due to the action of microorganisms. It was quickly discovered that the earth had grown sick.

Subsequent efforts involved sewage disposal straight into aquatic areas, but this significantly worsened the quality of the water in those bodies. As cities grew, there was a restricted quantity of land accessible for sewage treatment and disposal, primarily through irrigation and sporadic filtration. Additionally, as populations increased, the quantity of sewage produced increased quickly, and the declining grade of this enormous volume of sewage outpaced the waterways' and rivers' degree of self-purification capacity. As a result, different forms of sewage treatment were created in relatively tiny treatment centres to speed up the natural forces beneath regulated circumstances.

What is Sewage?

Wastewater generated by a group of individuals is referred to as sewage. Generally, a sewer system is used to carry it. Sewage is wastewater that is released from homes as well as from nearby businesses, industrial, and public institutions. Numerous dangerous compounds are present in the wastewater that drains from highways and rooftops. Waste that is liquid is sewage. Impurities are both dispersed and decomposed in sewage. Contaminants are another name for these pollutants.

Sewage Treatment Plant

The initial sewage treatment plans were created in response to the unfavourable effects of sewage disposal on the ecosystem and the awareness of public hygiene. There are numerous hazardous organic compounds in sewage. In sewage treatment plants, microorganisms are frequently utilised to remove this hazardous organic waste. Two phases make up a sewage treatment plant like primary and biological treatment phases which are explained below in detail.

Primary Treatment

It entails the scientific techniques utilised to remove massive or tiny elements from sewage.

Biological Treatment

Aerobic bacteria are injected further into sewage treatment plants as part of the biological treatment process. These microorganisms utilise the organic sewage elements and lessen the toxins. BOD (Biological oxygen demand) can be utilised to gauge this.

The sewage is transported from the treatment centre into a big tank after the biological treatment. Anaerobic bacteria in this sizable tank aid in the decompasition of waste. Biogas is created via decomposition and is utilised as a power source. Therefore, sewage regulation and the framework of the sewage treatment plant diagram are vital for preserving human wellbeing.

Domestic Sewage Treatment

Both large companies and small-scale residential buildings can use a sewage water treatment system. A domestic sewage water treatment plant is a facility located at residential housing that serves a smaller population. These plants are put in place in locations or on-premise where there is already a water shortage to avoid one. Domestic sewage primarily consists of waste products including paper, food, bathroom and kitchen sink effluent, human waste, and similar items. Prior to releasing the wastewater into the atmosphere, it is required to eliminate all of these wastes. Since the cleansed water is fit for reuse, it won't be wasted.

This will support the creation of a stable and environmentally favourable habitat and contribute to water conservation for a better future. Regardless of whether they are solid or extremely small, sewage water treatment plants can eliminate all significant contaminants from water. The household plant uses a technique to obtain high-quality purified water for this purpose.

Health Effects of Sewage

Wastewater and sewage both comprise bacteria, fungi, worms, and viruses which can attack the lungs, the digestive system, and other organs. Bacteria can result in vomiting, headaches, weakness, cramps, diarrhoea, fever, and occasionally even loss of appetite.

Waste is a favourable environment for fungi to develop. These can worsen asthma or trigger lung infections, as well as cause allergic reactions (like a runny nose). Viral infection damages the liver. The signs and symptoms include fatigue, stomach pain, nausea, jaundice (yellow skin), diarrhoea, and a lack of appetite.

Interesting Facts

  • The best environment for the growth of algae is sewage. It offers each and every nutrient required for algae development.

  • The Aquaflow Bionomic Corp. of New Zealand is now the 1st company in the world to create biofuel utilising algae that grows in sewage ponds.

  • One major plus of the human-sewage technique is that a sewage-derived alga seems to contain a significant amount of oil.

  • For organic decomposition to take place, aerobic bacteria required a lot of dissolved oxygen.

Key Features to Remember

  • Sewage is effectively the society's sewer system when it has been contaminated by a wide range of activities.

  • Sewage is the general term used to describe the wastewater released from domestic facilities such as homes, institutions, and commercial entities.

  • It is organic since it contains carbon compounds like human waste, paper, vegetable matter, etc. It is composed of 99.9% water and 0.1% solids.

  • To lessen the toxicity of sewage, preserve a clean and secure environment, and advance human well-being, sewage treatment is essential.

FAQs on Sewage

1. Why should Sewage be treated before disposal?

Sewage treatment entails breaking down complicated organic chemicals in the sewage into basic, stable forms without adverse reactions. This can be done physically, chemically, or biologically utilising microorganisms. Sewage should be treated before disposal because untreated sewage can lead to health hazards.

2. What is the different process involved in sewage treatment?

There are four different processes involved in sewage treatment.

  • Sedimentation

  • Breaking down contaminants

  • Sand filtration

  • Disinfection

3. What are the methods involved in disinfection?

Chlorine addition, Ultraviolet (UV) radiation, and ozone are the three methods involved in disinfection. Of the three methods, the ozone method is recommended as the safest one. The sludge will be heated after these steps which removes the germs from the water and makes it available for reuse.

4. What is the usage of bacteria digestion?

The most well-known way to lower BOD, COD, etc. in sewage is bacteria's digestion of organic materials. Untreated sewage is home to an abundance of anaerobic bacteria, which creates pungent H2S gas.