[PCDD/Fs distribution in MSWI fly ash and identification of the indicated isomer]

Four municipal solid waste incinerator (MSWI) fly ash samples were analyzed for PCDD/Fs. The toxicity equivalent quotient (TEQ) was 0.34 - 3.80 ng/g. The congeners distribution presented great comparability to each other as 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDF contributed about 33.6% - 40.5% of total TEQ. Combination with the published PCDD/Fs results of the long-term monitoring in MSWI fly ash in Shanghai, it was found that total TEQ had good correlation with 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDF contribution (r = 0.996 3 and 0.997 4 respectively), so they could be considered as indicator isomers for the rapid determination of TEQ evaluation, especially in long-term monitoring of one incinerator. The indicator factors were 4.466 4 and 3.164 6 respectively. The analysis of the PCDD/Fs results from different incinerators also showed good correlation with 2,3,4,7,8-PeCDF contribution (r = 0.984 9) and it could be considered as indicator isomer for TEQ evaluation of MSWI fly ash samples. The indicator factor was 3.4194.