Transformation of phosphorus by MgCl2 and CaCl2 during sewage sludge incineration.

Phosphorus (P) recovery from sewage sludge (SS) have been regarded as an effective method of P recycling. The effects of incineration temperature, incineration time, and chlorine additives on the distribution of P speciation during sludge incineration were studied. Moreover, the reactions between model compounds AlPO4 and additives (MgCl2 and CaCl2) were investigated by thermogravimetric differential thermal analysis and X-ray diffraction measurements. The results demonstrated that the increase in temperature and time stimulated the volatilization of non-apatite inorganic phosphorus (NAIP) instead of apatite phosphorus (AP). MgCl2 and CaCl2 can greatly promote the conversion of NAIP to AP. Additionally, AlPO4 reacted with MgCl2 are incinerated at 500-600 °C to form Mg3(PO4)2, which is mainly due to the reaction of the intermediate product MgO and AlPO4. Reactions between AlPO4 and CaCl2 occurred at 700-750 °C and produced Ca2PO4Cl, which can be directly used with high bioavailability. These findings suggested that chlorine additives in the SS incineration process can obtain phosphorus-containing minerals with higher bioavailability to realize the resource utilization of P in sludge. © 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.

Citation

Yunfeng Xu, Jingyan Chen, Fei Yang, Yangfan Fang, Guangren Qian. Transformation of phosphorus by MgCl2 and CaCl2 during sewage sludge incineration. Environmental science and pollution research international. 2021 Nov;28(42):60268-60275

Mesh Tags

Substances

PMID: 34156616

search → result