| Pollutants characteristics, especially in components and contents of heavy metals and PCDD/Fs, were chemical analyzed and toxicological evaluated in fly ash from 6 typical kinds of solid waste incinerators in Zhejiang province. The results indicated that the main elements in fly ash were Si, Ca, Al, Fe, K, Na and Cl. Among all kinds of heavy metals, the Zn content was the highest one, whose average was up to 9458 mg/kg. Meanwhile, the Cd, Zn, Cu,Cr,Ni, Pb and As contents in the fly ash samples were 642, 127, 22, 18,15, 10 and 2-fold of those in polluted soil, respectively. The leaching ratios of heavy metals in fly ash concluded according to the HJ/T 299-2007 Procedure were lower than its limitation. However, the leaching ratios from NB and LS sample concluded according to the Toxicity Characteristic Leaching Procedure (TCLP) exceeded its limitation. The TEQ of PCDD/Fs from all samples were lower than the limitation in GB 5085.6-2007, while higher than the soil-limitation in Canadian, New Zealand and Sweden, with 105, 59, 401, 369 and 5-fold in the sample HZ, WZ, NB, TZ and HUZ, respectively. It could be concluded that the components and contents of the pollutants were various from different fly ashes. The components of heavy metals were mainly affected by the type of solid wastes. And the technology of the incinerator played important role in the pollution characteristics in fly ash. Thus, it is of significant meaning to study the particulate pollution characteristics of a certain fly ash before disposal or reuse for the purpose of adequate risk assessment and management. |
