12. Conclusion

In conclusion, urban sewage sludge from urban wastewater treatment plants (STERU) is a complex waste product that presents both environmental challenges and recovery opportunities. These sludges are generated by wastewater treatment processes and contain a variety of organic substances, minerals, micro-organisms and water. Dealing with these sludges requires a meticulous approach that aims to minimize their environmental impact while seeking solutions for their reuse, in order to benefit from the nutrients and energy they contain.

Regulations governing the agricultural spreading of sludge require prior treatment to stabilize and hygienize it. These treatments include anaerobic digestion, composting, thermophilic aerobic stabilization, drying and incineration. Each method has its own specific features and impacts, and the choice of the most suitable technique will...