TY - JOUR
T1 - PCDD/PCDF behavior in low-temperature pyrolysis of PCP-contaminated sandy soil
AU - Thuan, Ngo Thi
AU - Dien, Nguyen Thanh
AU - Chang, Moo Been
N1 - Funding Information:
The authors gratefully acknowledge Pao Chen Hung and Shu Hao Chang for their assistance in analyzing PCDD/Fs and comments. The authors are pleased to acknowledge financial support provided by the National Science Council ( NSC 98-2221-E-008-019-M Y3 ) of the Republic of China.
PY - 2013/1/5
Y1 - 2013/1/5
N2 - This study investigates the behavior of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) formation, dechlorination and destruction in PCP-contaminated sandy soil by low-temperature thermal treatment. Experimental tests were carried out in a nitrogen atmosphere in the temperature range of 200-400°C with a treatment time of 30min. 70% of PCP removal from the soil was achieved, resulting in 1436±230ng/kg, the highest PCDD/F formation at 250°C; however, the highest toxic concentration was measured around 4.20±0.62ngTEQ/kg at 300°C with 80% PCP removal from the soil. Further analysis has revealed that OCDD is the most dominant congener that is supposed to be formed from the pyrolysis of PCP, while OCDF is the second prevailing congener, possibly due to pyrolysis of 2,3,4,5-TeCP being a main byproduct of PCP pyrolysis. Detection of less chlorinated dioxins and furans over 300°C indicates the dechlorination of highly chlorinated dioxins and furans, especially octachlorinated dibenzo-p-dioxin (OCDD) at 350°C and 400°C. Desorption from soil was supposed as a main mechanism for the distribution of PCDD/Fs in the gaseous phase, and not much difference in dioxins and furan levels was observed at 350°C and 400°C in the gaseous phase. Therefore, 350°C is the most appropriate temperature to remove most PCP and PCDD/Fs from soil, as well as to meet PCDD/F emission standards (0.1ngI-TEQ/Nm3).
AB - This study investigates the behavior of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) formation, dechlorination and destruction in PCP-contaminated sandy soil by low-temperature thermal treatment. Experimental tests were carried out in a nitrogen atmosphere in the temperature range of 200-400°C with a treatment time of 30min. 70% of PCP removal from the soil was achieved, resulting in 1436±230ng/kg, the highest PCDD/F formation at 250°C; however, the highest toxic concentration was measured around 4.20±0.62ngTEQ/kg at 300°C with 80% PCP removal from the soil. Further analysis has revealed that OCDD is the most dominant congener that is supposed to be formed from the pyrolysis of PCP, while OCDF is the second prevailing congener, possibly due to pyrolysis of 2,3,4,5-TeCP being a main byproduct of PCP pyrolysis. Detection of less chlorinated dioxins and furans over 300°C indicates the dechlorination of highly chlorinated dioxins and furans, especially octachlorinated dibenzo-p-dioxin (OCDD) at 350°C and 400°C. Desorption from soil was supposed as a main mechanism for the distribution of PCDD/Fs in the gaseous phase, and not much difference in dioxins and furan levels was observed at 350°C and 400°C in the gaseous phase. Therefore, 350°C is the most appropriate temperature to remove most PCP and PCDD/Fs from soil, as well as to meet PCDD/F emission standards (0.1ngI-TEQ/Nm3).
KW - Low temperature
KW - PCDD/F behavior
KW - Pentachlorophenol
KW - Pyrolysis
UR - http://www.scopus.com/inward/record.url?scp=84870659977&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2012.11.014
DO - 10.1016/j.scitotenv.2012.11.014
M3 - 期刊論文
C2 - 23220751
AN - SCOPUS:84870659977
VL - 443
SP - 590
EP - 596
JO - Science of the Total Environment
JF - Science of the Total Environment
SN - 0048-9697
ER -