Question:
The correct statement of comparison of Ultimate BOD (BODu), COD, Theoretical oxygen demand (ThOD), BOD\(_5\) is:
The correct statement of comparison of Ultimate BOD (BODu), COD, Theoretical oxygen demand (ThOD), BOD\(_5\) is:
Show Hint
Always remember: {Theoretical > Chemical > Biological (ultimate) > Biological (5-day)}.
Updated On: Feb 8, 2026
- BODu > COD > ThOD > BOD\(_5\)
- COD > ThOD > BODu > BOD\(_5\)
- ThOD > COD > BODu > BOD\(_5\)
- COD > BODu > BOD\(_5\) > ThOD
Hide Solution
Verified By Collegedunia
The Correct Option is C
Solution and Explanation
Step 1: Understanding oxygen demand terms.
ThOD represents the total oxygen required for complete oxidation of organic matter theoretically. COD measures chemically oxidizable matter, while BODu measures biologically oxidizable matter over infinite time. BOD\(_5\) measures oxygen demand over only 5 days.
Step 2: Comparing magnitudes.
Since ThOD assumes complete oxidation, it is the highest. COD is lower than ThOD as some matter may not be chemically oxidized. BODu is lower than COD because not all organic matter is biodegradable. BOD\(_5\) is the lowest since it measures oxygen demand for a limited time.
Step 3: Evaluating options.
(A) Incorrect ordering.
(B) Incorrect, ThOD cannot be lower than COD.
(C) Correct, it follows the correct decreasing order.
(D) Incorrect, ThOD should be the highest.
Step 4: Conclusion.
The correct comparison is ThOD > COD > BODu > BOD\(_5\).
ThOD represents the total oxygen required for complete oxidation of organic matter theoretically. COD measures chemically oxidizable matter, while BODu measures biologically oxidizable matter over infinite time. BOD\(_5\) measures oxygen demand over only 5 days.
Step 2: Comparing magnitudes.
Since ThOD assumes complete oxidation, it is the highest. COD is lower than ThOD as some matter may not be chemically oxidized. BODu is lower than COD because not all organic matter is biodegradable. BOD\(_5\) is the lowest since it measures oxygen demand for a limited time.
Step 3: Evaluating options.
(A) Incorrect ordering.
(B) Incorrect, ThOD cannot be lower than COD.
(C) Correct, it follows the correct decreasing order.
(D) Incorrect, ThOD should be the highest.
Step 4: Conclusion.
The correct comparison is ThOD > COD > BODu > BOD\(_5\).
Was this answer helpful?
0
0
Top Questions on Water Quality: Parameters and Measurement
- Color test of water is done with an instrument called
- OJEE - 2025
- Environmental Engineering
- Water Quality: Parameters and Measurement
- A real estate project on a 12 hectare site contains 6 buildings, each with ground coverage of 3 percent of the site area. The landscaped area is 40 percent of the site and rest of the area are roads. Assume coefficient of runoff for landscaped area and road area to be 0.15 and 0.6 respectively. Ignore the rainwater from the roof of the buildings and additional water from outside areas. Considering average rainfall intensity of 70 mm per hour, the estimated peak surface runoff rate from the site is ________ \(m^{3}\)/s. (rounded off to two decimal places)
- GATE AR - 2025
- Services and Infrastructure
- Water Quality: Parameters and Measurement
The graph shows the typical test result of a property of a building material. Identify the test and the variables represented on the X-axis and Y-axis from the given options.
- GATE AR - 2025
- Services and Infrastructure
- Water Quality: Parameters and Measurement
- A real estate project on a 12 hectare site contains 6 buildings, each with ground coverage of 3 percent of the site area. The landscaped area is 40 percent of the site and rest of the area are roads. Assume coefficient of runoff for landscaped area and road area to be 0.15 and 0.6 respectively. Ignore the rainwater from the roof of the buildings and additional water from outside areas. Considering average rainfall intensity of 70 mm per hour, the estimated peak surface runoff rate from the site is ________ \(m^{3}\)/s. (rounded off to two decimal places)
- GATE AR - 2025
- Services and Infrastructure
- Water Quality: Parameters and Measurement
- Which of the following method(s) is/are used for desalination of water?
- GATE AR - 2025
- Services and Infrastructure
- Water Quality: Parameters and Measurement
View More Questions
Questions Asked in OJEE exam
Consider the grammar $S \rightarrow aSa \mid bSb \mid a \mid b$. Which one of the following options correctly characterizes the language generated by the given grammar over the alphabet {a,b}
- OJEE - 2025
- Theory of Computations
- What is the value of the postfix expression: $6\ 12\ 2\ 4\ +\ /\ *\ ?$
- OJEE - 2025
- Data Structures
- Consider the following C function foo(int n). How many times does foo(2) get called on making the call foo(5)?
C Function:
float foo(int n){ if(n <= 2) return 1; else return (2*foo(n-1) + 3*foo(n-2)); }- OJEE - 2025
- Data Structures
If a concentrated load of 50 kN is applied at point C, then what will be the shear developed at point C?
- OJEE - 2025
- Strength of Materials
- To generate the $j^{\text{th}}$ column of the flexibility matrix
- OJEE - 2025
- Structural Analysis
View More Questions