1. Hygienize It and Spread It on Land:
2. Use it as Alternative Fuel source in the Cement Industry:
4. Make Coal:
5. Produce Biogas and Purify that Into Pipeline-Grade Methane:
6. Make a Sludge Compost Using USDA's Method:
7. Extract Gold from Sewage Sludge!
9. Extract energy from Sewage Sludge:
See also www.anaerobic-digestion.com/anaerobic-digestion-basics/anaerobic-sludge-digestion