Role of inorganic chlorides in formation of PCDDs, PCDFs, and coplanar PCBs from combustion of plastics, newspaper, and pulp in an incinerator.
The total amounts of dioxins found in exhaust gases from combustion of polyethylene (PE), polystyrene (PS), and poly(ethylene terephthalate) (PET) with approximately 3% (w/ w) NaCl were 6.07, 17.7, and 28.9 ng/g, respectively. Plastics containing benzene rings produced more dioxins than plastic containing no benzene ring. The amounts of dioxin formed in the exhaust gases from the combustion of newspapers impregnated with CaCl2, KCl, and NaCl were 18.6, 28.6, and 49.0 ng/g, respectively. Dioxin formation was associated with the bond energy between metal atom and chlorine atom. When newspapers impregnated with four different amounts of NaCl were combusted, the highest NaCl content newspaper (chlorine content 4.08%, w/w; lignin content 19.8%, w/w) produced the greatest amount of dioxins (174 ng/g). Pulp with NaCl (chlorine content 4.25%, w/w; lignin content 0.69%, w/w) produced more dioxins (6.71 ng/g) than pulp alone (0.799 ng/g) did upon combustion. The lignin content in a combustion sample correlated with the amount of dioxin formation. The results exhibited that combustion conditions with low CO concentration (<2 ppm) produced much less dioxins than conditions with high CO concentration (159 ppm).
Yasuhara
Akio
A
Research Center for Material Cycles and Waste Management, National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan.
Katami
Takeo
T
Okuda
Toshikazu
T
Shibamoto
Takayuki
T
D000393:Air Pollutants / Q000032:analysis* / Q000138:chemical synthesis; D002122:Calcium Chloride / Q000737:chemistry; D004147:Dioxins / Q000032:analysis* / Q000138:chemical synthesis; D004784:Environmental Monitoring / Q000379:methods; D005740:Gases / Q000032:analysis / Q000138:chemical synthesis; D006801:Humans; D017745:Incineration; D009524:Newspapers as Topic; D010969:Plastics; D011189:Potassium Chloride / Q000737:chemistry; D012037:Refuse Disposal / Q000379:methods; D012965:Sodium Chloride / Q000737:chemistry; D014934:Wood
D000393:Air Pollutants; D004147:Dioxins; D005740:Gases; D010969:Plastics; D012965:Sodium Chloride; D011189:Potassium Chloride; D002122:Calcium Chloride