title: Transformation of apatite phosphorus and non-apatite inorganic phosphorus during incineration of sewage sludge.
abstract: The recovery of phosphorus from incinerated sewage sludge ash (SSA) is assumed to be economical. Transformation from non-apatite inorganic phosphorus (NAIP) to apatite phosphorus (AP), which has a higher bioavailability and more extensive industrial applications, was studied at 750-950°C by sewage sludge incineration and model compound incineration with a calcium oxide (CaO) additive. Thermogravimetric differential scanning calorimetry analysis and X-ray diffraction measurements were used to analyze the reactions between NAIP with CaO and crystallized phases in SSA. High temperatures stimulated the volatilization of NAIP instead of AP. Sewage sludge incineration with CaO transformed NAIP into AP, and the percentage of AP from the total phosphorus reached 99% at 950°C. Aluminum phosphate reacted with CaO, forming Ca2P2O7 and Ca3(PO4)2 at 750-950°C. Reactions between iron phosphate and CaO occurred at lower temperatures, forming Ca(PO3)2 before reaching 850°C.
authors.affiliation: The Key Laboratory of Clean Energy Liaoning Province, Shenyang Aerospace University, Shenyang, China. Electronic address: rdlee@163.com.
authors.forename: Rundong
authors.initials: R
authors.lastname: Li
authors.affiliation: The Key Laboratory of Clean Energy Liaoning Province, Shenyang Aerospace University, Shenyang, China.
authors.forename: Ziheng
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: The Key Laboratory of Clean Energy Liaoning Province, Shenyang Aerospace University, Shenyang, China.
authors.forename: Yanlong
authors.initials: Y
authors.lastname: Li
authors.affiliation: The Key Laboratory of Clean Energy Liaoning Province, Shenyang Aerospace University, Shenyang, China.
authors.forename: Wenchao
authors.initials: W
authors.lastname: Teng
authors.affiliation: The Key Laboratory of Clean Energy Liaoning Province, Shenyang Aerospace University, Shenyang, China.
authors.forename: Weiyun
authors.initials: W
authors.lastname: Wang
authors.affiliation: The Key Laboratory of Clean Energy Liaoning Province, Shenyang Aerospace University, Shenyang, China.
authors.forename: Tianhua
authors.initials: T
authors.lastname: Yang
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry; D001031:Apatites / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry; D002152:Calorimetry, Differential Scanning; D003460:Crystallization; D005296:Ferrous Compounds / Q000737:chemistry; D017745:Incineration; D010087:Oxides / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry; D010758:Phosphorus / Q000032:analysis* / Q000737:chemistry*; D012722:Sewage / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D017607:Aluminum Compounds; D001031:Apatites; D017610:Calcium Compounds; D005296:Ferrous Compounds; D010087:Oxides; D010710:Phosphates; D012722:Sewage; D010758:Phosphorus; C016538:lime; C518753:ferrous phosphate; C012714:aluminum phosphate
keywords: Apatite phosphorus; Non-apatite inorganic phosphorus; Sewage sludge ash; Thermogravimetric analysis–differential scanning calorimetric analysis; Transformation; X-ray diffraction