Volume 16, No. 12, December 2016, Pages 3175-3186 PDF(402 KB)
Characterization of PAHs and PCBs in Fly Ashes of Eighteen Coal-Fired Power Plants
Zhiyong Li1, Lan Chen1, Songtao Liu1, Huiqiao Ma1, Lei Wang2, Caixiu An2, Ruiling Zhang3
1 School of Environmental Science and Engineering, North China Electric Power University, Baoding 071000, China
2 Central Laboratory of Geology and Mineral Resources of Hebei Province, Baoding 071003, China
3 School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin 300384, China
- Systematically research on PAHs and PCBs in fly ashes from 18 coal-fired power plants.
- PAH diagnostic ratios and profile were studied.
- The PAHs were well correlated with TOC values, PCBs showed not this trend.
- Higher carcinogenic PAHs, PCB TEQ level indicated CFAs using should be cautioned.
- PAHs in CFPPs with low generation unit were higher than high generation unit.
For the management of coal fly ashes (CFAs) from coal-fired power plants (CFPPs), characterization of PAHs and PCBs in CFAs is imperative. The 18 PAH and 86 PCB congeners in CFAs collected from 18 large-scale CFPPs in China were detected using GC/MS system. The PAH concentrations were in the range of 5.51–70.9 ng g–1 for 16 CFPPs with individual block power capacity as 600 MW (IBPC-600), significantly lower than 886–916 ng g–1 for 2 CFPPs with IBPC as 200 and 300 MW (IBPC-200/300). Both PAH and PCB congeners for 18 CFPPs were dominated by low molecular weight ones. The 3- and 2-ring PAHs, di-, tri- and tetra-PCBs were the predominant homologs. PAH profiles for 16 CFPPs with IBPC-600 were significantly different from other industrial stacks based on higher coefficients of divergence. The BaP-based toxic equivalency (BaPeq) concentration and BaP-based equivalent carcinogenic power (BaPE) for 16 CFPPs with IBPC-600 were 0.834 ng g–1 and 0.570, much lower than corresponding 20.5 ng g–1 and 15.4 for 2 CFPPs with IBPC-200/300. No difference existed for Σ86PCBs between CPFFs with IBPC-600 and -200/300, which ranged from 9.60 to 32.1 ng g–1. Higher mean carcinogenic PAH concentrations for 2 CFPPs with IBPC-200/300 and PCBs-TEQ concentration for 18 CFPPs indicated the application of CFAs as soil amendment should be prohibited. The PAH concentrations for 18 CFPPs were well correlated with the total organic carbon (TOC) values, while PCB concentrations showed not this trend, indicated the different formation mechanism between PCBs and PAHs.
PAHs; PCBs; Coal fly ash; Coal-fired power plant.