Environmental Impact Of PCDD/F Emissions On Soil From The Hazardous Waste Incineration Plant

With the rapid development of social economy,the production of hazardous waste(HW) are increasing daily. Due to the advantages of detoxification,mass reduction and reclamation of incineration technology,hazardous waste incineration disposal centers are booming up in mainland China. However, the potential secondary pollution from the facility has been the social focus, especially the environmental toxics and associated health effects of the emissions of Polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs). In order to establish effective measures to control the emissions of PCDD/Fs from the hazardous waste incinerators(HWI), it is important to get the PCDD/Fs pollution conditions around the hazardous waste incineration plant.From 2008 year to 2009 year, we traced and monitored the concentrations and fingerprint of PCDD/Fs from the soils around the HWI in Hangzhou,China.The concentrations of PCDD/Fs in flue gas and fly ash of the HWI were also measured in this paper.Conclusions are as follows.The concentration of international equivalence quantity(I-TEQ) of soils in 2008 ranged from 0.48 to 42.37 ng TEQ kg-1, the mean value was 7.35 ng I-TEQ kg-1, and median value was 5.85 ng I-TEQ kg-1. In 2009, the concentrations of the soils ranged 0.65-41.75 ng I-TEQ kg-1, the mean value was 9.94 ng I-TEQ kg-1, and the median value for 7.36 ng I-TEQ kg-1. Data showed that in 2008 year,before the operation of the HWI,the soils around the HWI has received relatively serious pollution. On the other hand, the temporal variations (2008-2009) of the total concentration and I-TEQ value in soils increased by 22.83% and 25.81% (median value),respectively. Homologue, congener concentration and congener I-TEQ fingerprint were analysed among the soils.As for two years, those three fingerprint characteristics are similar, OCDD is the major contributors for the three fingerprint.PCDD/Fs emission from flue gas of the incineration plant were 0.021-0.845 ng TEQ Nm-3,PCDD/Fs concentration of fly ash was 2.55 ng I-TEQ g-1 and 1.81 ng TEQ g-1. The cogener I-TEQ profiles of flue gas and fly ash are rather similar.2,3,4,7,8-PeCDF was main contributor to total I-TEQ, followed by HxCDF toxic homologue. PCDFs took a larger proportion than PCDDs.Through the PCDD/Fs concentration analysis of 15 soil samples in hangzhou old industrial area, new industrial area and tourist area, we got the results as follows: The I-TEQ of soils in old industrial area ranged 0.65～41.75 ng I-TEQ kg-1 with average 12.73 ng I-TEQ kg-1, which is higher than the other two areas. The I-TEQ of soils in the new industrial area and tourism area ranged (average) 0.61-1.33 ng I-TEQ kg-1 (1.07 ng I-TEQ kg-1) and 1.53～2.11 ng I-TEQ kg-1 (1.81 ng I-TEQ kg-1), respectively. The comparisons of congener patterns of soil and flue gas samples indicated that the soil samples were influenced not only by the investigated incineration source emissions, but also by other potential sources.