Water is necessary for the survival of all life forms on Earth. As a result, it is crucial that we protect water from pollution and conserve it. Increasing biochemical oxygen demand levels in water are inflicting havoc on the ecosystem of water bodies, which in turn is taking a toll on the entire ecology of the biosphere, as a whole. It is our obligation to protect these ecosystems.
Environmental resources are accessible to other life forms on an equal basis to humans. We must put our greed aside and try to protect water bodies and lower BOD levels.
Let’s understand the effects of BOD on water quality!
What is BOD or biological oxygen demand?
A measurement of the amount of oxygen needed by microorganisms (such as aerobic bacteria), in the oxidation of organic materials is called biochemical oxygen demand (BOD).
It is calculated by comparing the dissolved oxygen levels in a sample over a five-day period. BOD is frequently referred to as BOD-5 due to the standard time. The values for the dissolved oxygen are typically in parts per million (ppm).
What do high and low BOD values indicate?
A higher BOD indicates a greater need for oxygen, which leaves less available for oxygen-dependent organisms to consume, and denotes poorer water quality.
Conversely, a low BOD indicates that less oxygen is being taken out of the water, making the water in general purer. Since, cold water holds onto oxygen better than warm water does, dissolved oxygen levels are often lower in the summer.
Untreated sewage typically has BOD levels between 200 and 600 ppm, while unpolluted rivers often have values below 1 ppm (or 1 mg/L).
How is the Biological Oxygen Demand (BOD) affected by water pollution?
The amount of oxygen in water will be diminished if excessive amounts of organic waste are introduced. As a result, aquatic life that depends on oxygen perishes. Also, bacteria that don't need oxygen (anaerobic bacteria) start to break down the organic waste, producing substances that are bad for people's health and have a terrible odour.
As these organic wastes are broken down by aerobic (oxygen-requiring) bacteria, the amount of dissolved oxygen in the water is reduced. Hence, the amount of BOD in the water is a gauge of how much oxygen is necessary, for the biological breakdown of the organic material.
As a result, BOD levels in the water increase when sewage and river water are combined.
Techniques for Lowering BOD in Water
The biological oxygen requirement of water can be decreased using the following techniques.
1. Fenton's reagent (H2O2+FeSO4), H2O2/UV, O3/UV, and more sophisticated oxidation processes.
2. Coagulation with cationic polymers or alum.
3. Sedimentation and flocculation.
4. For adsorption, activated charcoal is employed.
5. Fluctuation caused by electricity.
6. Reverse Osmosis.
7. Dissolved air flotation technique.
Conclusion
Water or wastewater treatment is a crucial component in numerous applications. It involves a lot of moving pieces, whether you want to make bottled water or need clean-disinfected water for industrial activities. Thus, the biological oxygen requirement is one of the most crucial steps in the treatment of wastewater.
How can we assist?
Water treatment, wastewater treatment, sewage treatment, effluent treatment, along with the physical, chemical, and biological treatment processes, are provided by Netsol Water.
Netsol combines cutting-edge technology with years of experience to handle the most challenging, water treatment or wastewater treatment requirements of a wide range of clients. For further information, contact us at +91 9650608473 or email at enquiry@netsolwater.com
