ENVIRONMENTAL ENGINEERING - Finding Eco-friendly ingenious ways of disposing wastewater

Dear readers today i am going to discuss some basic aspects of waste water treatment plant as to how and why it is carried out.
Environmental Engineering is the branch of Engineering that deals with the contemporary issues of society related to water resources.
Infrastructure development ensues huge harm to the environment due to increasing levels of Air Pollution, Noise Pollution and Water Pollution that is affecting the health of living organisms in one way or another. To antagonize this effect environmentalists, scientists, scholars, engineers are contemplating on this subject so as to coin various methods that can reduce the harm caused by pollution. As an initiative step towards reducing water pollution environmental engineers have designed various techniques to treat the waste water generated from houses and industries so that it can be disposed off effectively in water bodies or can be used for fulfilling other purposes like watering the gardens, medians etc.
To accomplish the above cited task water treatment is divided into three main categories namely:

1. Primary Treatment
2. Secondary Treatment
3. Tertiary Treatment

In the first step waste water is passed through primary treatment units where any solid matter present in it is filtered out by making use of screenings, filters etc. In the next step water is allowed to pass through various units like sedimentation tanks, grit chambers etc. where heavy suspended solids are settled down during detention period. Then finally primary treated water is passed through various units involving chemical and biological treatment of water that is known as tertiary treatment. After water is passed through all the three stages of treatment, it is disposed off in the water bodies without altering oxygen demand.
Oxygen Demand is the amount of oxygen required for the aquatic life to survive. As the pollution in water body increases, the living organisms in the form of bacteria, microorganisms etc. As a result those bacteria and various flora and fauna present in the water body will consume oxygen already present in the water body for their survival resulting in increased oxygen demand. This amount of oxygen required for the survival of living organisms is known as Biochemical Oxygen Demand (BOD). The high values of BOD in water sample indicates high degree of pollution due to larger number of bacteria present in water.
So 5-day BOD value of the sample is determined before disposing off the water in water body because if BOD value is higher it will pose danger to aquatic life. That is why it is necessary that before disposing off the waste water in the streams or rivers it should be properly treated in Waste Water Treatment Plant.
Following video will help in understanding the process of water treatment more effectively.

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