Journal of hazardous materials
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This study investigated the presence and concentration of 16 U. S. EPA priority controlled PAHs in gas, bio-oil and residues from the pyrolysis of different sewage sludges. ⋯ With the increase of pyrolysis temperature from 450℃ to 850℃, it has been observed an increase of PAHs concentration in the bio-oils as follows: 16 % (ISS), 1.3 % (food manufacture wastewater sludge, FSS), 194 % (printing and dyeing wastewater sludge, PDSS), 334 % (DSS). 2, 3 and 4-ring PAHs dominate, and their total mass proportion is over 70 %. In gas, the types and concentrations of PAHs were less than in bio-oil. PAHs yield in solid was very low, and a trace content of PAHs of 0.0161 mg kg-1 was detected from the solid after the pyrolysis of DSS, while PAHs in solid for ISS and FSS are even non-existent and would cause fewer environmental problems.