Distribution of sixteen kind of EPA-PAHs in pyrolysis bio-oil from four sorts of different wastewater sewage sludge was investigated. The influences of free PAHs of raw sewage sludge and phi-chemical characteristics (carbon content

H/C molar ratio

O/C molar ratio and volatile content) of the sludge on PAHs distributions were discussed. The results showed that the bio-oil produced from pyrolysis of different sludge contained sixteen kinds of EPA-PAHs in different extent. A decreasing order of content of PAHs in the different bio-oil was as followed: Industrial wastewater sewage sludge in dying (21.72 mg·kg-1) > household wastewater sewage sludge (14.10 mg·kg-1) > paper manufacturing wastewater sewage sludge (13.72 mg·kg-1) > food production wastewater sewage sludge (5.48 mg·kg-1). The PAHs of bio-oil were majorly consisted of two

three and four rings of PAHs

and their amount was accounted for more than 95% of the total concentrated PAHs. The concentration distributions of different rings of PAHs were closely related with the concentrations of the free PAHs of raw sewage sludge. In addition

it was found that the distributions of PAHs in bio-oil was also dependent of the phi-chemical characteristics of raw sludge. Along with the phi-chemical properties of sludge varied

the PAHs concentrations of three and four rings presented a similar variation trend. Their maximum contents were obtained at 30.96% of carbon content

1.1 of H/C molar ratio

0.33 of O/C molar ratio and 35.5% of volatile contents. The maximum content of two rings of PAHs was obtained at 20.75% of carbon content

1.44 of H/C molar ratio

0.6 of O/C molar ratio and 46.30% of volatile contents.