Influence of combustion temperature on formation of nitro-PAHs and decomposition and removal behaviors in pilot-scale waste incinerator.
To gain a better understanding of the formation and decomposition behaviors of nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) in solid waste combustion, incineration experiments were conducted using a pilot-scale incinerator. Nitro-PAHs were formed during primary combustion, although the amounts formed were several orders of magnitude lower than those of the PAHs, PCDD/Fs, and the dioxin-like PCBs. Increasing the temperature of primary combustion from 690 to 890 degrees C resulted in a significant decrease in the formation of most of the nitro-PAH compounds studied. More than 99% of nitro-PAHs formed in the primary combustion zone were decomposed in the secondary combustion chamber at 900 degrees C with a 3-s residence time. The results indicate that appropriate secondary combustion conditions are the key to controlling emissions of nitro-PAHs. Under optimized conditions, the amounts of nitro-PAHs in the final off gases and in the ashes were significantly lower than those present in the incinerator input. Overall destruction efficiencies of nitro-PAHs reported in this study were 95.81-98.33%, indicating that emission of nitro-PAHs from solid waste combustion can be minimized by appropriate combustion control.
Watanabe
Mafumi
M
Research Center for Material Cycles and Waste Management, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan. watanabe.mafumi@nies.go.jp
Noma
Yukio
Y
D006358:Hot Temperature; D017745:Incineration / Q000295:instrumentation*; D010865:Pilot Projects; D011083:Polycyclic Compounds / Q000737:chemistry* / Q000302:isolation & purification
D011083:Polycyclic Compounds