Detoxifying PCDD/Fs and heavy metals in fly ash from medical waste incinerators with a DC double are plasma torch.
Medical waste incinerator (MWI) fly ash is regarded as a highly toxic waste because it contains high concentrations of heavy metals and dioxins, including polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Therefore fly ash from MWI must be appropriately treated before being discharged into the environment. A melting process based on a direct current thermal plasma torch has been developed to convert MWI fly ash into harmless slag. The leaching characteristics of heavy metals in fly ash and vitrified slag were investigated using the toxicity characteristic leaching procedure, while the content of PCDD/Fs in the fly ashes and slags was measured using method 1613 of the US EPA. The experimental results show that the decomposition rate of PCDD/Fs is over 99% in toxic equivalent quantity value and the leaching of heavy metals in the slag significantly decreases after the plasma melting process. The produced slag has a compact and homogeneous microstructure with density of up to 2.8 g/cm3.
Institute of Environmental Science &Technology, Hangzhou Dianzi University, Hangzhou 310018, China. panxinchao@126.com
Xinchao
X
Pan
Jianhua
J
Yan
Zhengmiao
Z
Xie
D019342:Acetic Acid / Q000737:chemistry; D000393:Air Pollutants / Q000737:chemistry*; D001572:Benzofurans / Q000737:chemistry*; D060729:Coal Ash / Q000737:chemistry*; D000072338:Dibenzofurans, Polychlorinated; D055664:Electrochemical Techniques; D017745:Incineration; D008506:Medical Waste; D019216:Metals, Heavy / Q000737:chemistry*; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000737:chemistry; D058989:Vitrification; D018505:Waste Management / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry
D000393:Air Pollutants; D001572:Benzofurans; D060729:Coal Ash; D000072338:Dibenzofurans, Polychlorinated; D008506:Medical Waste; D019216:Metals, Heavy; D000072317:Polychlorinated Dibenzodioxins; D014874:Water Pollutants, Chemical; D019342:Acetic Acid