Characterization of Inorganic Elements within PM2.5 and PM10 Fractions of Fly Ashes from Coal-Fired Power Plants

Zhiyong Li; Yaqin Ji; Huiqiao Ma; Peng Zhao; Xiangchao Zeng; Songtao Liu; Yunjun Jiang; Lei Wang; Aiqin Liu; Huiying Gao; Fude Liu; John Kennedy Mwangi

doi:10.4209/aaqr.2017.02.0071

Characterization of Inorganic Elements within PM2.5 and PM10 Fractions of Fly Ashes from Coal-Fired Power Plants

Zhiyong Li ¹, Yaqin Ji², Huiqiao Ma¹, Peng Zhao¹, Xiangchao Zeng¹, Songtao Liu¹, Yunjun Jiang³, Lei Wang¹^,3, Aiqin Liu³, Huiying Gao¹, Fude Liu⁴, John Kennedy Mwangi ⁵^,6

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¹School of Environmental Science and Engineering, North China Electric Power University, Baoding, Hebei 071000, China
²School of Environmental Science and Engineering, Nankai University, Tianjin 300071, China
³Central Laboratory of Geology and Mineral Resources of Hebei Province, Baoding, Hebei 071003, China, China
⁴School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin 300384, China
⁵School of Resources and Environmental Engineering, Hefei University of Technology, Hefei 230009, China
⁶Department of Environmental Engineering, National Cheng Kung University, Tainan 70101, Taiwan

Received: February 27, 2017
Revised: March 13, 2017
Accepted: March 13, 2017
Download Citation: ||https://doi.org/10.4209/aaqr.2017.02.0071

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Cite this article:
Li, Z., Ji, Y., Ma, H., Zhao, P., Zeng, X., Liu, S., Jiang, Y., Wang, L., Liu, A., Gao, H., Liu, F. and Mwangi, J.K. (2017). Characterization of Inorganic Elements within PM2.5 and PM10 Fractions of Fly Ashes from Coal-Fired Power Plants. Aerosol Air Qual. Res. 17: 1105-1116. https://doi.org/10.4209/aaqr.2017.02.0071

HIGHLIGHTS

Inorganic elements were analyzed within PM_2.5 and PM₁₀ for power plant fly ashes.
Contamination levels for 13 heavy metals were determined based on Igeo values.
Element profiles between any two power plants were similar for PM_2.5 or PM₁₀.
Relative enrichment factors for most elements were found to be lower than 1.30.

ABSTRACT

In this study 15 fly ash samples were collected from 15 large-scale coal-fired power plants (CFPPs) in China. The samples were then re-suspended through PM_2.5 and PM₁₀ inlets and analyzed for the contents of 39 inorganic elements (IEs) using inductively coupled plasma-mass spectroscopy (ICP-MS) and inductively coupled plasma-optical emission spectrometry (ICP-OES). The results show that the particle size distributions for the 15 FAs samples exhibited bimodal patterns. The Ʃ₃₉IEs (g g^–1) for the PM_2.5 (0.292–0.564) in all the 15 CFPPs were higher than that of PM₁₀ (0.269–0.403). Except for Cu, all the other 38 IEs were more enriched in the PM_2.5 with the PM_2.5/PM₁₀ ratios being 1.06–1.73. Considering 13 heavy metals, the same orders occurred between PM_2.5 and PM₁₀ with Al >> Cr > Zn > Mn > Cu > V > Pb > Sn > Co > As > Sb > Tl > Cd. More attention should be paid to the high contents of Cr in both PM_2.5 (1310 mg g^–1) and for PM₁₀ (1240 mg g^–1) from all 15 CFPPs. 23 IEs for PM₁₀ and 26 IEs for PM_2.5 had the geo-accumulation index (Igeo) values higher than 0, indicating different pollution levels for them. On the other hand, there was moderate to extreme levels of pollution for Cr, Zn, Cu, Pb, Sn, Sb, Tl, Cd and Al based on Igeo values. The element profiles for PM_2.5 or PM₁₀ from 15 CFPPs were similar based on low coefficients of divergence for PM_2.5 (0.254 ± 0.038) and PM₁₀ (0.244 ± 0.054) according to the comparison between any two CFPPs. Most elements with low relative enrichment factors (REF) as less than 0.70 or 0.70–1.30 indicated no or weak condensation occurred for them during coal combustion, while Cr, Cu, Zn, Sn, W and Pb had REF values higher than 1.30 indicated that significant condensation occurred for these elements.