The migration and transformation of phosphorus in sewage sludge during the pyrolysis process were studied based on standard measurement testing (SMT)

analyzing the phosphorus in the treated sludge samples using nuclear magnetic spectrum and X-ray diffraction

and also the occurrence and distribution of phosphorus in the residue of the sewage sludge sample after pyrolysis. From the results obtained

with increasing heat treatment temperature

the organic phosphorus continuously transformed to inorganic phosphorus. Phosphorus was concentrated in the residue of the sludge after pyrolysis when the pyrolysis temperature was below 800℃. With increasing pyrolysis temperature

the content of total phosphorus (TP)

inorganic phosphorus (IP)

apatite phosphorus(AP) in the sludge showed a trend of gradual increases

while the non-apatite inorganic phosphorus (NAIP) content indicated a trend of fluctuation with an increase and then decreases. The increase of pyrolysis temperature led NAIP transform into AP

and AP content reached the maximum in 800℃. XRD results showed that the main forms of NAIP in the sludge were aluminum phosphate and ferric phosphate. The content of calcium phosphate in the sludge sample increased with increasing temperature. From the results of 31P NMR

the orthophosphoric acid monoester was converted to orthophosphate after heating

and orthophosphate was the most stable form of phosphorus. After the heat treatment

phosphorus was mainly in the form of orthophosphate. The new understanding on phosphorus migration and transformation in the process of sludge pyrolysis was discovered

and the theoretical support for the harmless

resource utilization and phosphorus pollution control technology of sludge was provided.