Q1: Pick up the correct statement from the following :

ANS:E - All the above.

The correct statement from the options provided is: All the above. Each statement is accurate:

1. The pH value indicates the acidity and alkalinity of sewage. A pH value below 7 indicates acidity, while a pH value above 7 indicates alkalinity.
2. In acidic sewage, the pH value is less than 7. This statement aligns with the general understanding of pH and acidity.
3. In alkaline sewage, the pH value is more than 7. This statement is consistent with the definition of alkalinity and pH values.
4. Fresh sewage is generally alkaline. This statement is often true because sewage tends to undergo biological processes that produce alkaline compounds as organic matter decomposes.