ANS:A - fertilizer

Dried sewage after treatment is commonly used as fertilizer. After sewage undergoes treatment processes such as digestion, dewatering, and drying, the resulting biosolids contain valuable nutrients such as nitrogen, phosphorus, and potassium, along with organic matter. These biosolids can be further processed and treated to produce a stable, nutrient-rich material that resembles compost or organic fertilizer. The use of dried sewage biosolids as fertilizer offers several benefits:

1. Nutrient Recycling: Biosolids contain valuable nutrients that can be recycled and used to improve soil fertility and crop productivity.
2. Organic Matter: Biosolids add organic matter to soil, improving soil structure, water retention, and nutrient availability for plants.
3. Waste Reduction: Recycling sewage biosolids as fertilizer reduces the volume of waste that needs to be disposed of in landfills, contributing to sustainable waste management practices.