Activated sludge process is concerned with waste management. It is a

Options

A. (a) chemical treatment
B. (b) biological treatment
C. (c) mechanical means
D. (d) nuclear means

Answer

**Step-by-Step Text Solution:**

1. **Understanding the Activated Sludge Process**: The activated sludge process is a method used in sewage treatment that focuses on the biological breakdown of organic matter in wastewater.

2. **Sewage Treatment Steps**: The sewage treatment process consists of three primary steps:
- **Primary Treatment**: This involves mechanical processes such as filtration and sedimentation to remove large solids from sewage water.
- **Secondary Treatment**: This is also known as biological treatment. It involves the use of microorganisms to decompose organic matter in the sewage. The sewage is passed through aeration tanks where microorganisms, such as bacteria and protozoans, digest the organic material, thereby reducing the Biological Oxygen Demand (BOD) of the sewage.
- **Tertiary Treatment**: This is the final stage of treatment, often referred to as disinfection. It includes chemical treatments, such as the use of chlorine and UV rays, to further purify the water.

3. **Role of Microorganisms**: In the secondary treatment, microorganisms form what is known as "activated sludge." This sludge is a mass of microorganisms that work to break down organic matter in the sewage, which helps in significantly lowering the BOD levels.

4. **Conclusion**: Since the activated sludge process is primarily involved in the secondary treatment of sewage, which is a biological treatment, the correct answer to the question is that the activated sludge process is concerned with biological treatment.

**Final Answer**: The activated sludge process is concerned with waste management as a biological treatment.

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