The correct answer is D. All of the above.
The pH scale is a measure of how acidic or alkaline a substance is. A pH value of 7 is neutral. A pH value below 7 is acidic, and a pH value above 7 is alkaline.
Sewage is a mixture of wastewater from homes and businesses, as well as industrial waste. It can be acidic or alkaline, depending on the sources of the wastewater.
Acidic sewage can cause problems for the environment, as it can corrode pipes and other infrastructure. It can also harm plants and animals.
Alkaline sewage can also cause problems for the environment, as it can kill plants and animals. It can also make water unsafe to drink.
It is important to monitor the pH of sewage to ensure that it is not too acidic or alkaline. This can be done by using a pH meter. If the pH of sewage is too high or too low, it can be treated to bring it back to a neutral pH.
Here are some additional details about each option:
- Option A: pH value indicates acidity and alkalinity of sewage. This is true. The pH scale is a measure of how acidic or alkaline a substance is. A pH value of 7 is neutral. A pH value below 7 is acidic, and a pH value above 7 is alkaline.
- Option B: In acidic sewage, the pH value is less than 7. This is true. If the pH of sewage is less than 7, it is acidic.
- Option C: In alkaline sewage, the pH value is more than 7. This is true. If the pH of sewage is more than 7, it is alkaline.