Chemical characteristics and risk assessment of typical municipal solid waste incineration (MSWI) fly ash in China

• Published in: Journal of hazardous materials Vol. 261; pp. 269 - 276
• Main Authors: Pan, Yun, Wu, Zhiming, Zhou, Jizhi, Zhao, Jun, Ruan, Xiuxiu, Liu, Jianyong, Qian, Guangren
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.10.2013; Elsevier
• Subjects: Applied sciences; cadmium; Chemical characteristics; Chemical engineering; chemical speciation; China; Coal Ash - analysis; Crystallization, leaching, miscellaneous separations; Environmental Pollutants - analysis; Exact sciences and technology; fly ash; General treatment and storage processes; Heavy metals; Incineration; leaching; lead; Metals, Heavy - analysis; MSWI fly ash; municipal solid waste; Pollution; Principal component analysis; risk; Risk Assessment; Risk assessment code; Safety; Solid Waste; toxicity; Urban and domestic wastes; waste incineration; Wastes; zinc; China; MSWI fly ash; Risk assessment code; Heavy metals; Chemical characteristics; Principal component analysis; Waste dumping; Heat treatment; Pollutant behavior; Toxicity; Urban waste; Mobility; Risk analysis; Heavy metal; Transport process; Fly ash; Incineration; Risk assessment; Solid waste; Lead; Lixiviation; Speciation
• ISSN: 0304-3894; 1873-3336; 1873-3336
• DOI: 10.1016/j.jhazmat.2013.07.038

•Fly ashes from 15 MSWI plants were collected all over China.•Excessive leaching of Zn, Pb and Cd were observed in over 40% of samples.•The mobility of heavy metal was strongly relative to their acid soluble fraction.•Cd and Pb posed a very high risk to the environment. The release of heavy metals in municipal solid waste incineration (MSWI) fly ash has become a worrying issue while fly ash is utilized or landfilled. This work investigated the potential mobility of heavy metals in the fly ashes from 15 typical MSWI plants in Chinese mainland by the characterization of distribution, chemical speciation and leaching behavior of heavy metals. The results showed that total content of heavy metals decreased in the order Zn>Pb>Cu>Cr>Ni>Cd in samples. The toxicity characteristics leaching procedure (TCLP) of fly ash indicated that the amount of leached Cd in 67% of samples exceeded the regulated limit. Also, the excess amount of leached Zn and Pb was observed in 40% and 53% of samples, respectively. The chemical speciation analysis revealed that this excess of heavy metal leached in TCLP was contributed to the high content of acid soluble fraction (F1) and reducible fraction (F2) of heavy metal. Moreover, the great positive relevance between leaching behavior of heavy metals and F1 fraction was supported by principal component analysis (PCA). Risk assessment code (RAC) results suggested that Cd and Pb showed a very high risk class to the environment.