Explain why some times foaming is seen in river water near the place where sewage water is poured after treatment ?

Explanation

### Step-by-Step Solution:

1. **Understanding Sewage Water Composition**:
- Sewage water contains various impurities, including surfactants and detergents. These substances are often used in household cleaning products.

2. **Nature of Detergents**:
- Detergents are a type of surfactant, which can be anionic, cationic, or neutral. They have cleansing properties and can work effectively in both hard and soft water.

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