An Innovative Technology to Minimize Biological Sludge Production and Improve Its Quality in a Circular Economy Perspective

In the coming years, the production of biological sewage sludge is set to increase. According to the European legislation, the management of sludge, as well as other waste, must follow a hierarchical approach according to which the first place in order of priority is represented by the prevention/minimization of the production. Over the last few years, thermophilic aerobic processes proved to be effective in minimizing the production of sludge within wastewater treatment plants (WWTPs). Thermophilic aerobic/anoxic membrane reactor (TAMR) technology combines the advantages of thermophilic aerobic treatments with those of biological membrane processes. This work reviews the literature concerning the application of TAMR focusing on the prevention of the production of biological sludge and on the improvement of its quality for the purpose of a possible recovery in agriculture in a circular economy perspective. The results show that the process is mature and effective for full-scale application in conventional WWTPs.