1. What is Threshold Odor Number?

The Threshold Odor Number (T_o) refers to the dilution factor at which the odor is just detectable. It is a measure used to quantify the intensity of odors in water and wastewater samples.

2. How Does the Calculator Work?

The calculator uses the Threshold Odor Number formula:

Where:

• \( T_o \) — Threshold Odor Number
• \( V_s \) — Volume of Sewage (m³)
• \( V_d \) — Volume of Distilled Water (m³)

Explanation: The formula calculates the dilution factor required to make the odor just barely detectable to the human nose.

3. Importance of T_o Calculation

Details: Threshold Odor Number measurement is crucial for assessing water quality, monitoring wastewater treatment effectiveness, and ensuring compliance with environmental regulations regarding odor control.

4. Using the Calculator

Tips: Enter the volume of sewage and volume of distilled water in cubic meters. Both values must be positive numbers with sewage volume greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: What does a higher Threshold Odor Number indicate?
A: A higher T_o value indicates a stronger odor that requires more dilution to become barely detectable.

Q2: What are typical T_o values for different water sources?
A: Clean drinking water typically has T_o values of 1-3, while wastewater can have values ranging from 10 to over 100 depending on treatment level.

Q3: How is the odor detection test conducted?
A: Trained panelists smell serial dilutions of the sample to determine the point where odor becomes just detectable.

Q4: Are there limitations to this measurement?
A: Yes, T_o measurement is subjective and depends on the sensitivity of the testers. Environmental factors and individual variations can affect results.

Q5: How often should odor testing be performed?
A: Regular testing is recommended for wastewater treatment plants, especially when process changes occur or odor complaints are received.