Thermal treatment of polychlorinated dibenzo-p-dioxins and dibenzofurans from contaminated soils.
Thermal treatment technology was used to remove polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from heavily contaminated soil. For a soil with an original PCDD/F content of 35,970ng International Toxic Equivalents (I-TEQ)/kg, >99.99% PCDD/F removal efficiency was obtained with a primary furnace at two different treatment temperatures (750 degrees C and 850 degrees C), while a secondary furnace at 1200 degrees C gave >98% decomposition efficiency. The total PCDD/F I-TEQ contents in treated soils at 750 degrees C and 850 degrees C were 1.56ngI-TEQ/kg and 2.15ngI-TEQ/kg, respectively, which were far below the soil pollution standard of Taiwan (1000ngI-TEQ/kg soil). Although air pollution control devices had significant effects on the removal of PCDD/Fs, the total I-TEQ concentrations in the upstream flue gas of PUF cartridge at 750 degrees C and 850 degrees C (2.61ngI-TEQ/Nm(3) and 2.38ngI-TEQ/Nm(3), respectively) were still higher than the stationary emission limit of the Taiwan EPA (0.5ngI-TEQ/Nm(3)). The above results also suggested that additional APCDs, such as activated carbon injection in front of the filter are needed to enhance PCDD/F removal efficiency.
Lee
Wen-Jhy
WJ
Department of Environmental Engineering, National Cheng Kung University, Tainan City, Taiwan.
Shih
Shun-I
SI
Chang
Chih-Yuan
CY
Lai
Yi-Chieh
YC
Wang
Lin-Chi
LC
Chang-Chien
Guo-Ping
GP
D001572:Benzofurans / Q000737:chemistry*; D052918:Environmental Restoration and Remediation; D006358:Hot Temperature; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis*; D013696:Temperature
D001572:Benzofurans; D000072317:Polychlorinated Dibenzodioxins; D012989:Soil Pollutants; C023614:dibenzofuran