A Comprehensive Guide to Treatment of Sewage Water

The containment of water resources available on the earth has made it nearly impossible to consume the water in its naturally available form. Because of water pollution, water bodies, as well as other sources of water, have been greatly affected. Since water is a limited resource, it is important to reuse water available in various forms.

Apart from reusing the water, to prevent the situation of water pollution from getting worsened, it is the most basic and necessary step that the wastewater is treated before being dumped into other water bodies. The wastewater already has a very high amount of chemicals, toxins and other products that make the water unfit. If this polluted water is dumped directly into the water bodies without any precautions, the vegetation underwater will disappear. Fishes and other animals will die due to the toxins. Plantations and any other natural life forms will not be able to survive due to lack of oxygen as the polluted water does not have enough amount of oxygen mixed with it.

Every industry and every household must ensure the proper treatment of wastewater before dumping it. Treatment of wastewater makes it less harmful and less polluting for the receiving body. Treatment of sewage water is, however, a long and systematic process but it is very simple and could be easily followed by small as well as large scale industries.

The process of treatment of water begins with the transportation of water from one place to another. The water is transported from the place of usage to the place where it will be treated using pipes and canals. After the water is sent to the sewage treatment plant or the place specified for the process, the following steps are followed to clean the water:

STEP: 1- Screening

The first and foremost step in the process of treatment of wastewater is screening. When the used water is collected at the place where it is to be treated, the solid waste is separated from water using special types of equipment. This waste might include diapers, plastic bags, wrappers, cloth pieces, sanitary napkins, bottles, etc. This waste is separated to ensure that it does not act as a blockade in the further steps of the process. Some special equipment is also designed for screening of water for large scale industries that produce gillions of liquid waste daily.

STEP: 2 – Primary treatment

After screening the solid waste and separating it from the other liquid material the next step to be followed is the primary treatment. In this stage, organic solid waste in the form of human waste is separated from the wastewater. This is done through a process. In this process, the wastewater is collected in large settlement tanks. Wastewater is then stored in these tanks and allowed to settle. The settled solid waste is known as ‘Sludge’. These settlement tanks are necessarily circular in the bottom as their circular bottom allows the waste to be settled continuously during the process. The collected sludge is then transferred for further processing while the water is shifted for the treatment to the other stage.

STEP: 3 – Secondary treatment

At the stage of the secondary treatment, the water is again put in large tanks. But in this stage, the tanks are rectangular shaped. These rectangular tanks are known as Aeration lanes. During the whole process, the air is continuously pumped into the water. This will make sure that the remaining bacteria in the water will be broken into the tiniest of bits. Now, bacteria are scraped off from the water in the same manner as the sludge scraping process.

STEP: 4 – Final treatment

The last step in the process of treatment of wastewater receives almost treated wastewater with fewer bacteria and impurities. Just like the other stages of the process, in this stage also water is contained in a large tank and allowed to settle. After the water gets settled in the bottom, sludge is formed due to bacterial action. Again, the sludge is taken off from the process and collected separately for treatment purposes. After this, the wastewater is nearly completely free from any bacteria or chemical impurities. As the last step of the process, the water is run through a wall of sand where the remaining impurities are also removed.

After this whole process, the wastewater is fit for dumping. It will now result in less or no harm to the vegetation underground. When this filtered water is released into the river, it is the same as the wastewater from a small household and free form all the harmful chemical substances.

Why is a sewage treatment plant important?

There are various reasons due to which treatment of wastewater is crucial for all industries as well as the environment. These same reasons are the highlights behind the necessity of having a sewage treatment plant. Following are the main reasons as to why a sewage treatment plant is paramount for any industry:

1. Environmental safety: Environmental pollution is one of the major concerns that has been put forward by almost all organizations around the world. Water pollution is considered to be one of the most blatant and dangerous forms of pollution as water is the most basic necessity of life for every being on the earth. So, to protect the environment from getting degraded and saving the earth from the disasters, the environment must be protected in the smallest manner possible. Treatment of wastewater results in the reduction of water pollution and hence, an overall reduction in the amount of environmental pollution.
2. Protecting Vegetation: Water is one of the most important sources of vegetation on earth. It is because of water, that the seeds can grow into a matured plant. A diverse life and ecological system also exist underwater just like on the ground. The riverbeds and ocean beds are covered with thousands of microorganisms as well as gigantic animals and plants. If the water is not safe for consumption and filled with chemicals and hazardous substances, the vegetation that exists underwater will come to an end. This will result in an ecological imbalance which will ultimately result in disasters.
3. Preventing water-borne diseases: Water is something that is consumed likely by the rich as well as the poor. It is consumed by human beings, animals and is required for the cultivation of food for them. If the wastewater is dumped without any treatment into the water bodies, the water in them will become unfit for consumption. This also contaminates groundwater which is a source of growth of edible plants. When any person consumes plants that are infected with harmful chemicals and waste, they are very vulnerable to catch diseases like Cholera, Diarrhoea, Food poisoning, Typhoid, fever, viral and bacterial infections as well. To prevent such water-borne diseases, the water must be protected from being polluted. This could be largely done through sewage treatment plants and purifying the wastewater before dumping it.
4. Escaping fines and penalties: The governments have also issued clear guidelines about the dumping of wastewater into water bodies. If the level of waste and poisonous chemicals is found to exceed the governmental standards, heavy fines and penalties are imposed on such industries by the courts. So, to escape such additional liabilities and penal actions in the normal course of business, it is better than the firms follow the rules and regulations that have been provided by the government.
5. Fulfilling corporate social responsibility: Corporate social responsibility is a new concept in the world of business, but it has gained worldwide attention in a very short period. It is a concept wherein all the businesses are required to give up some part of their total earnings towards a social cause and fulfilling their responsibilities towards society. Every business needs to fulfill its corporate social responsibility to attain goodwill in the market. Greater the goodwill of the firm more will be its business. So, to grow in the long run and increase profitability, the firms should install water treatment plants.

The best sewage treatment plant is the one that is available at the minimal cost and is the most efficient in segregating waste material and water before it gets dumped into other water bodies.

Where can STP be used?

It is important to mention that the efficiency of the plant is determined largely by the place where it is being used. Hence, some tips regarding where the sewage treatment plants should be used are provided below:

1. A sewage treatment plant should be installed in all small, medium and large-scale enterprises that dump waste into the environment. All those industries that use water or liquid form of elements as raw material should ideally have a sewage treatment plant.
2. A sewage treatment plant should be installed as per the directions and guidelines of the government or the regulatory framework if any.
3. A sewage treatment plant should be established near the place where the waste is dumped into the water bodies. It could only be installed at a place where the process of production ends.
4. The plant should be set up after making due considerations about transportation of water from one place to another, it should hence, be located nearest to the water bodies and tanks.
5. The equipment and the size of the tanks should be compatible with the scale of the industry. Advanced technology and equipment should be used during the process to minimize other forms of pollutions as well.
6. A sewage treatment plant should not be set up in residential areas as the water and waste from these plants will create a lot of problems for the people living in such areas.

The above-mentioned precautions and tips would ensure that the firm can take out maximum benefits from the treatment plants. Its location is very important in determining the effectiveness and efficiency of its working.

Current Laws and Penalties

Taking into consideration the seriousness of the issue of environmental and water pollution, the Government of India has issued specific guidelines and framework for the firms. Although the guidelines and laws are very exhaustive, a simpler expression of them is provided here.

• The government has made it mandatory for all the housing apartments to have a sewage treatment plant if they do not have an underground drainage system.
• The government of India has passed various legislations from time to time to deal with the problem of environmental issues. Some of these legislations deal specifically with water pollution and lays down the guidelines that have to be followed for dumping anything into the water bodies. This dump could be in the form of industrial waste as well as household waste.
• Some of these legislations are:

1. Water (Prevention and Control of Pollution) Act of 1974, amended in 1988
2. Water (Prevention and Control of Pollution) Cess Act of 1977, amended in 1991
3. Air (Prevention and Control of Pollution) Act of 1981, amended in 1987
4. Environment (Protection) Act of 1986 (EPA)
5. Public Liability Insurance Act of 1991
6. National Environmental Tribunal Act of 1995
7. National Environmental Appellate Authority Act of 1997

• Various institutions and committees have also been formed to regulate the dump of untreated waste into the water bodies.
• There is a provision that a heavy fine or imprisonment or both could be awarded to the owner of the firm which dumps untreated waste into the water bodies. The licenses of such firms could also be suspended at the discretion of the concerned authorities.

Based on all these factors, it is safe to imply that every country around the globe including India has started to take some serious steps in the direction of saving the environment. Steps are also being taken to protect and enrich the water resources. Sewage treatment plants are playing an active role in that process and hence should be installed in every industry or household that dumps waste directly into the nearby water bodies. This will help in saving human life as well as the ecology.