Question:
What is the significance of measuring Biochemical Oxygen Demand (BOD) in sewage water?
ADetermines the nutrient content
BEstimates the amount of biodegradable organic matter
CEstimates the microbial diversity
DIndicates the pH of the water
Answer:
B. Estimates the amount of biodegradable organic matter
Explanation:
Biochemical Oxygen Demand (BOD):
- Biochemical Oxygen Demand (BOD) is a critical parameter used to assess the amount of organic pollutants in water, particularly in sewage and wastewater.
- BOD is a measure of the amount of dissolved oxygen needed by microorganisms to break down organic substances present in water over a specific period, usually five days at 20 degrees Celsius.
- It is expressed in milligrams of oxygen per liter (mg/L) of water.
- The test involves incubating a water sample in the dark to encourage microbial decomposition of organic substances.
- Microorganisms use oxygen during this process, and the rate of oxygen consumption is measured.
Significance:
- BOD serves as an indicator of the organic pollution level in water.
- BOD is crucial in designing and operating wastewater treatment plants.
- It helps determine the effectiveness of treatment processes in reducing the organic load before discharging treated water back into the environment.
- BOD is used to assess the potential impact of discharged sewage or industrial effluents on receiving water bodies.
- High BOD values suggest a higher concentration of biodegradable organic matter, such as sewage or other contaminants.
- High BOD levels downstream can deplete dissolved oxygen, harming aquatic life.
- Low BOD values indicate that the water contains fewer biodegradable organic pollutants, suggesting good water quality.