Partition of heavy and alkali metals during sewage sludge incineration
Partition of heavy and alkali metals during sewage sludge incineration
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DOI：
10.1021/ef0501602
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发表时间：
2006-03-01
期刊：
影响因子：
5.3
通讯作者：
Kanaoka, C
中科院分区：
文献类型：
--
作者：
Han, J;Xu, MH;Kanaoka, C
本文采用热力学平衡计算和燃烧室实验两种方法研究了污泥焚烧过程中重金属和碱金属的转化规律。在这些实验中，研究了重金属和碱金属在不同温度（800，700，600，400和200摄氏度）下的分布。化学平衡计算表明，蒸发的金属化合物在不同温度下形成凝聚相。计算结果表明，在500 ℃时，蒸发的铅化合物开始向固相转化。烟气中固体铅的主要种类是PbCl 2（s），低于500 ℃。Zn和K具有相同的温度范围（300-500 ℃），而As的转化温度为600 ℃，Na和Cu的转化温度高于800 ℃。实验结果也证明了根据重金属和碱金属的气固相变温区分离重金属和碱金属的可行性。根据实验结果，Pb和K的最佳分离温度为< 400 ℃，As为600 ℃，Cu，Zn和Na为800 ℃。
In this paper, two approaches are used to investigate the transformation of heavy and alkali metals during sewage sludge incineration: a thermodynamic equilibrium calculation and experiments using a bench-scale combustor. The distribution of heavy and alkali metals at different temperatures (800, 700, 600, 400, and 200 degrees C) is studied in these experiments. The chemical equilibrium calculation shows that vaporized metallic compounds form a condensed phase at different temperatures. The calculation results show that vaporized lead compounds begin to transfer to the solid phase at 500 degrees C. The main species of solid lead in the flue gas is PbCl2(s) below 500 degrees C. Zn and K have the same temperature range (300-500 degrees C), while the conversion temperature for As is 600 degrees C and that for Na and Cu is above 800 degrees C. The experimental results also prove the feasibility of separating heavy and alkali metals according to their gas-solid transformation temperature zones. On the basis of the experimental results, the optimum separation temperature is < 400 degrees C for Pb and K, 600 degrees C for As, and 800 degrees C for Cu, Zn, and Na.