Biology Waste Water Story Part 6 (Secondary treatment of Sewage) Class 7 VII

TL;DR

In the secondary treatment of sewage, living organisms, specifically aerobic microbes, help in removing impurities from wastewater through a biological process.

Transcript

hello friends this video on wastewater story part six is brought to you by exam fear dot com no more fear from exam i will proceed with the secondary treatment of sewage and this is again very important but here the the beautiful thing that we will see is it is not exactly a physical treatment rather a biological treatment so here we will see that ... Read More

Key Insights

• 😒 Secondary treatment of sewage involves the use of aeration tanks to support the growth of aerobic microbes.
• 💦 The goal is to reduce the polluting potential of water by removing organic impurities through biological decomposition.
• ❓ Biochemical Oxygen Demand (BOD) is used as a measure to determine the progress and effectiveness of the treatment process.
• 🥶 The settled wastewater, free from organic impurities, is passed on to settling tanks, where the activated sludge settles at the bottom.
• ❓ The activated sludge can be reused as a starter in the aeration tanks or can undergo further treatment in anaerobic sludge digesters.
• 🍳 Anaerobic sludge digesters utilize anaerobic bacteria to break down the remaining organic matter in the sludge.
• 🫢 During the digestion process, gases like methane and carbon dioxide are emitted and can be collected as bio gas.

Questions & Answers

Q: What is the primary difference between primary and secondary treatment of sewage?

The primary treatment of sewage involves physical removal of solid impurities, while secondary treatment relies on the biological decomposition of organic matter by aerobic bacteria.

Q: How do aerobic microbes contribute to the treatment of sewage?

Aerobic microbes break down complex organic substances into simpler forms, consuming organic impurities present in the wastewater in the presence of oxygen.

Q: What is the significance of aeration tanks in the secondary treatment process?

Aeration tanks, also known as aerators, supply oxygen to promote the growth and activity of aerobic microbes, facilitating the decomposition of organic matter in wastewater.

Q: How is the progress of secondary treatment determined?

The progress is measured using Biochemical Oxygen Demand (BOD), which indicates the amount of oxygen consumed by aerobic microbes and reflects the level of organic impurities present in the water.

Summary & Key Takeaways

• Secondary treatment of sewage involves the use of aeration tanks where air is pumped in to promote the growth of aerobic microbes.

• These aerobic microbes decompose organic substances in the presence of oxygen, leading to the removal of organic impurities from wastewater.

• Biochemical Oxygen Demand (BOD) is a measure used to determine the polluting potential of water, indicating the amount of oxygen utilized by the aerobic organisms.