An experimental and thermodynamic equilibrium investigation of the Pb, Zn, Cr, Cu, Mn and Ni partitioning during sewage sludge incineration
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- 作者：Jingyong Liu ; www053991@126.com" class="auth_mail" title="E-mail the corresponding author ; Jiewen Fu ; Xun'an Ning ; Shuiyu Sun ; Yujie Wang ; Wuming Xie ; Shaosong Huang ; Sheng Zhong
- 关键词：Sludge incineration ; Heavy metal ; Chlorine ; Thermodynamic equilibrium calculations
- 刊名：Journal of Environmental Sciences
- 出版年：2015
- 出版时间：1 September 2015
- 年：2015
- 卷：35
- 期：Complete
- 页码：43-54
- 全文大小：1492 K
文摘
The effects of different chlorides and operational conditions on the distribution and speciation of six heavy metals (Pb, Zn, Cr, Cu, Mn and Ni) during sludge incineration were investigated using a simulated laboratory tubular-furnace reactor. A thermodynamic equilibrium investigation using the FactSage software was performed to compare the experimental results. The results indicate that the volatility of the target metals was enhanced as the chlorine concentration increased. Inorganic-Cl influenced the volatilization of heavy metals in the order of Pb > Zn > Cr > Cu > Mn > Ni. However, the effects of organic-Cl on the volatility of Mn, Pb and Cu were greater than the effects on Zn, Cr and Ni. With increasing combustion temperature, the presence of organic-Cl (PVC) and inorganic-Cl (NaCl) improved the transfer of Pb and Zn from bottom ash to fly ash or fuse gas. However, the presence of chloride had no obvious influence on Mn, Cu and Ni. Increased retention time could increase the volatilization rate of heavy metals; however, this effect was insignificant. During the incineration process, Pb readily formed PbSiO4 and remained in the bottom ash. Different Pb compounds, primarily the volatile PbCl2, were found in the gas phase after the addition of NaCl; the dominant Pb compounds in the gas phase after the addition of PVC were PbCl2, Pb(ClO4)2 and PbCl2O4.