School of Environment, Tsinghua University, 100084 Beijing, PR China.
J Hazard Mater. 2011 Sep 15;192(3):1609-15. doi: 10.1016/j.jhazmat.2011.06.085. Epub 2011 Jul 5.
The influence of CO(2) content and SO(2) presence on the leaching toxicity of heavy metals in municipal solid waste incinerator (MSWI) fly ash was studied by examining the carbonation reaction of MSWI fly ash with different combinations of simulated incineration flue gases. Compared with raw ash, the leaching solution pH of carbonated ash decreased by almost 1 unit and the leaching concentrations of heavy metals were generally lower, with that of Pb decreasing from 19.45 mg/L (raw ash) to 4.08 mg/L (1# carbonated ash). The presence of SO(2) in the incineration flue gas increased the leaching concentrations of heavy metals from the fly ash to different extents after the carbonation stabilization reaction. The pH of the leaching solution was the main factor influencing the leaching concentrations of heavy metals. The increase in buffer capacity with the pH of carbonated ash caused an increase in heavy metal stability after the carbonation reaction. Accelerated carbonation stabilization of MSWI fly ash could reduce its long-term leaching concentrations (toxicity) of Cu, Pb, Se, and Zn. The leaching concentrations of heavy metals from carbonated ash also likely had better long-term stability than those from raw ash. The presence of SO(2) in the incineration flue gas increased the proportion of exchangeable state species of heavy metals; slightly increased the long-term leaching toxicity of Cu, Pb, Se, and Zn; and reduced the long-term stability of these metals in the fly ash after the carbonation reaction.
研究了 CO(2) 含量和 SO(2) 存在对城市固体废物焚烧（MSWI）飞灰中重金属浸出毒性的影响，方法是考察了不同模拟焚烧烟气条件下 MSWI 飞灰的碳酸化反应。与原灰相比，碳酸化灰的浸出液 pH 值降低了近 1 个单位，重金属的浸出浓度通常较低，其中 Pb 的浸出浓度从 19.45mg/L（原灰）降至 4.08mg/L（1#碳酸化灰）。焚烧烟气中 SO(2) 的存在会在碳酸化稳定反应后不同程度地增加飞灰中重金属的浸出浓度。浸出液 pH 值是影响重金属浸出浓度的主要因素。碳酸化灰的缓冲能力随 pH 值的增加导致碳酸化反应后重金属稳定性增加。加速 MSWI 飞灰的碳酸化稳定可降低其 Cu、Pb、Se 和 Zn 的长期浸出浓度（毒性）。碳酸化灰浸出的重金属也可能比原灰具有更好的长期稳定性。焚烧烟气中 SO(2) 的存在增加了重金属可交换态物种的比例；略微增加了 Cu、Pb、Se 和 Zn 的长期浸出毒性；并降低了这些金属在碳酸化反应后的飞灰中的长期稳定性。
