School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, China.
Environ Sci Technol. 2013 Feb 19;47(4):2123-30. doi: 10.1021/es304127k. Epub 2013 Feb 6.
The emission, mass balance, and distribution characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) as well as those of heavy metals (Hg, Cd, Pb, Cr, and Cu) were investigated during the cocombustion of 5%, 10%, 15%, and 20% sewage sludge (SS) in a pulverized coal power plant. The PCDD/F emissions increased from 7.00 to 32.72 pg I-TEQ/Nm(3) as the amount of SS in the mixed fuel (MF) increased. High sulfur content and relatively low chlorine levels in MF resulted in lower PCDD/F emissions. SS exhibited a remarkable difference in congener profiles compared with flue gas, bottom ash, and fly ash. The negative dioxin mass balance indicated that the cofiring of SS with coal in power plants was not a source but a sink of dioxins. The concentrations and emission factors of heavy metals in flue gas and bottom ash, as well as fly ash, all exhibited a tendency to increase with increasing input values of heavy metals in MF. The distribution characteristics of the investigated heavy metals were primarily dependent on the evaporative properties of these metals. The availability of chlorine could alter the heavy metal distribution behavior. The emitted pollutants in the power plant were below the legal limits.
研究了在煤粉发电厂中，5%、10%、15%和 20%的污水污泥（SS）共燃烧时，多氯二苯并对二恶英和呋喃（PCDD/Fs）以及重金属（Hg、Cd、Pb、Cr 和 Cu）的排放、质量平衡和分布特征。随着混合燃料（MF）中 SS 含量的增加，PCDD/F 的排放量从 7.00 增加到 32.72 pg I-TEQ/Nm(3)。MF 中高硫含量和相对低氯水平导致 PCDD/F 排放量较低。SS 的同系物分布特征与烟气、底灰和飞灰相比存在显著差异。负二恶英质量平衡表明，SS 与煤在电厂中的共燃不是二恶英的来源，而是其汇。烟气、底灰和飞灰中重金属的浓度和排放因子均表现出随 MF 中重金属输入值增加而增加的趋势。所研究的重金属的分布特征主要取决于这些金属的挥发性。氯的可用性可能会改变重金属的分布行为。电厂排放的污染物低于法定限值。
