Suppressing effect of goethite on PCDD/F and HCB emissions from plastic materials incineration.
Polyethylene (PE) and polyvinyl chloride (PVC) are the leading plastics in total production in the world. The incineration of plastic-based materials forms many chlorinated compounds, such as polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). In this study the addition of goethite (alpha-FeOOH) was investigated to determine its suppressing effect on the emission of PCDD/Fs and hexachlorobenzene (HCB) during the combustion of wastes containing PE and PVC. Goethite was being considered since it acts as a dioxin-suppressing catalyst during incineration. Results showed that incorporation of goethite greatly reduced the generation of PCDD/Fs and HCB in the exhaust gas and fly ash. The concentration of PCDD/Fs in flue gas decreased by 45% for lab-scale and 52% for small incinerator combustion experiments, where the goethite ratios in feed samples were 0.54% and 0.34%, respectively. Under the same conditions, the concentration of HCB in flue gas decreased by 88% and 62%, respectively. The present study showed a possible mechanism of the suppressing effect of the goethite for PCDD/F formation. It is likely that iron chlorides react with particulate carbon to form organo-chlorine compounds and promote PCDD/F formation in the gas phase. XRD analysis of combustion ash revealed that the goethite was partially dehydrated and converted to alpha-Fe(2)O(3) and Fe(3)O(4) but no iron chlorides formation. Therefore the goethite impregnated plastics can contribute the reduction of PCDD/Fs and HCB in the exhaust gas during incineration of MSW.
Jin
Guang-Zhu
GZ
School of Environmental Science and Engineering, POSTECH, San 31, Hyojadong, Namgu, Pohang 790-784, Republic of Korea.
Lee
Se-Jin
SJ
Kang
Jung-Ho
JH
Chang
Yoon-Seok
YS
Chang
Yoon-Young
YY
D001572:Benzofurans / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry; D060729:Coal Ash; D000072338:Dibenzofurans, Polychlorinated; D006581:Hexachlorobenzene / Q000737:chemistry*; D017745:Incineration / Q000295:instrumentation / Q000379:methods*; D058085:Iron Compounds / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D008903:Minerals; D052638:Particulate Matter / Q000737:chemistry; D010969:Plastics / Q000737:chemistry*; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000737:chemistry
D001572:Benzofurans; D060729:Coal Ash; D000072338:Dibenzofurans, Polychlorinated; D058085:Iron Compounds; D008903:Minerals; D052638:Particulate Matter; D010969:Plastics; D000072317:Polychlorinated Dibenzodioxins; C094886:goethite; D006581:Hexachlorobenzene; D002244:Carbon