Dried _______ is used as manure.

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question:** The question asks for a specific type of dried material that is used as manure.

2. **Identifying the Relevant Concept:** In the context of wastewater treatment, there is a byproduct known as sludge. Sludge is the semi-solid material that settles at the bottom of sewage treatment tanks.

3. **Explaining Sludge:** Sludge is created from the treatment of wastewater, which contains impurities and pathogens. During the treatment process, solid waste, including human feces, settles down and forms sludge.

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