Investigation of controlling factors on toxic metal leaching behavior in municipal solid wastes incineration fly ash

Tong，Lizhi1,2; Tang，Yi2,3; Wang，Feng2,3; Hu，Bin2,3; Shi，Pixing2,3; Hu，Qing2,3

2019-10-01

10.1007/s11356-019-06123-9

ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH   影响因子和分区

0944-1344

1614-7499

Municipal solid wastes incineration (MSWI) fly ash has drawn worldwide attention for its substantial annual generation capacity and high toxic metals leachability. Although many factors have been shown to affect the leachability of metals in fly ash, the controlling factors, which guide the selection of appropriate risk reduction method, remain unclear. The purpose of this study was to evaluate the effects of the two most important factors, total metal content, and remaining alkaline substances of MSWI fly ash, on the leaching behavior of toxic metals. In this work, a series of leaching tests and sequential extraction procedures were performed for seven fly ash samples collected from one MSWI plant. Results show that particulate size distribution, morphology, and mineralogy of all samples are similar, indicating the effects of these properties on metal leaching behavior can be ignored. In leaching tests, although the leaching behavior in terms of metal species and concentration levels vary as expected, only the leachate Pb concentration in four samples (up to 17.32 mg/L) exceeds the threshold in Chinese regulation (0.25 mg/L). The variation of the leachate Pb concentration is not consistent with the change of the total Pb concentration in fly ash. Further correlation analysis evidences that the acid-soluble Pb, which is highly correlated to the calcium content of fly ash, dominates the concentration of leachate Pb. Notably, when the addition of lime is about 1.5 times over the theoretical value, the concentration of leachate Pb would exceed the threshold regardless of the total Pb concentration in fly ash. Overall, this study demonstrates that the remaining alkaline substances (mainly calcium-bearing compounds), rather than the total content of metals, are the controlling factor of metal leaching behavior in fly ash. Thus, strategies to delicately optimize the quantity of lime addition in acid gas purification process should be considered to minimize MSWI fly ash environmental risks in the future.

Hazardous wastes Leaching pattern Lime addition Toxic elements Waste management

SCI

英语

通讯

National Key Research and Development Program[2018YFC1902904]

Environmental Sciences & Ecology

Environmental Sciences

WOS:000500035700075

SPRINGER HEIDELBERG

ENVIRONMENT/ECOLOGY

2-s2.0-85070289886

Scopus

1.School of EnvironmentHarbin Institute of Technology,Harbin,150090,China
2.School of Environmental Science and EngineeringSouthern University of Science and Technology,Shenzhen,518055,China
3.Engineering Innovation Center of Southern University of Science and Technology,Beijing,100083,China

Tong，Lizhi,Tang，Yi,Wang，Feng,et al. Investigation of controlling factors on toxic metal leaching behavior in municipal solid wastes incineration fly ash[J]. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH,2019,26(28):29316-29326.

Tong，Lizhi,Tang，Yi,Wang，Feng,Hu，Bin,Shi，Pixing,&Hu，Qing.(2019).Investigation of controlling factors on toxic metal leaching behavior in municipal solid wastes incineration fly ash.ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH,26(28),29316-29326.

Tong，Lizhi,et al."Investigation of controlling factors on toxic metal leaching behavior in municipal solid wastes incineration fly ash".ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH 26.28(2019):29316-29326.