Thermal treatment of sewage sludge: A comparative review of the conversion principle, recovery methods and bioavailability-predicting of phosphorus

A new breakthrough in the P recovery from sewage sludge ash by thermochemical processes

“…Literature reports that the Ca 3 (PO 4 ) 2 conversion to CaNaPO 4 occurs at temperatures ranging from 900 to 1000°C. 11 The results (not reported here, see supporting S1) show that the use of the chamber is mandatory to obtain a suitable temperature, even if it was demonstrated that MW can decrease the reaction's activation energy, making them less energyintensive. To verify the sustainability of the treatment, energy consumption and associated carbon dioxide emission are evaluated in comparison to the ASHDEC thermochemical process 12 (see Table 2, and S2), which is realised at the industrial level.…”

“…They contain different amounts of P. The core process used in this work is based on already established thermochemical reactions occurring in a devoted kiln, where the SSA is mixed with a sodium source and a reducing agent (for example dry sewage sludge, anthracite, graphite) and treated at a temperature operating around 1000 °C for more than 15 min. 11 Usually, fuel is also added to take advantage of the temperature rise. The reaction is based on the calcium ions partial replacement by sodium ions in the phosphates.…”

Challenges and opportunities for citrus wastewater management and valorisation: A review

“…The use of efficient sludge dewatering and drying system might considerably decrease the amount of sludge to be disposed. In this context, thermal drying systems of excess sludge allow evaporating significant amount of water in the sludge thereby reducing the final weight to be disposed (Zhu et al, 2022). In the frame of citrus industries, there are several thermal waste streams that could be used as a heat source (e.g.…”

Investigation of the Pyrolysis of Animal Manure in a Laboratory-Scale Tubular Reactor: The Effect of the Process Temperature and Residence Time

“…Environmental regulations establish limits on the values allowed for the usage of sewage sludge in agriculture. The excessive use of manure on land causes problems such as contamination of the subsoil and surface, odors as well as the emission of greenhouse gases and ammonia [5,[7][8][9][10].…”

“…For example, thermal conversion techniques such as pyrolysis and gasification could be alternatives for transforming the residue into valuable products such as oil, char and gaseous products. Additional advantages of these techniques are that the huge volume generated is reduced, microorganisms are degraded and pathogenic organisms destroyed [1,[9][10]. It is important to take into consideration that the percentage of humidity in the residues in the material is high and should be reduced while using the thermal techniques.…”