氯化剂对垃圾焚烧飞灰中重金属挥发特性的影响

The effect of chlorination agents on the volatilization of heavy metals in fly ash from municipal solid waste incinerator

以南方某生活垃圾焚烧厂飞灰及其水洗灰为原料进行高温热处理,考察氯化剂(CaCl2、MgCl2·6H2O、AlCl3、NaCl和FeCl3·6H2O)对飞灰和水洗灰中重金属的挥发作用.结果表明,除NaCl外,其他氯化剂均可促进飞灰和水洗灰中重金属的挥发,对于不同的重金属,其氯化剂的影响效果不同.在原灰中,Zn的挥发率受氯化剂影响最大,其次是Cd和Cu,在未添加氯化剂的情况下,飞灰中的Pb几乎全部挥发.水洗灰中重金属的挥发率受氯化剂影响更明显,其中Zn和Cu最为显著,添加氯化剂后,水洗灰中4种重金属的挥发率最高均达到95%以上.

The effect of chlorination agents on volatilization of heavy metals in fly ash from municipal solid waste incinerator （MSWI） was evaluated in this article. Four heavy metals were studied, including Cu, Pb, Cd and Zn in thermal treated fly ash and water-washing ash from a MSWI in a southern city of China. The chlorination agents that evaluated in this study included CaCl2、 MgCl2·6H2O、 AlCl3, NaCl and FeCl3·6H2O. Most chlorination agents could promote the volatilization of heavy metals both in fly ash and water-washing ash except NaCl and chlorination agents had different effect on the volatilization of different heavy metals. For the four heavy metals in the fly ash, more than 90% of Pb had already been volatilized even with no chlorination agents, and the effect of chlorination agents on the volatilization of Zn was greater than that of Cd and Cu. Whilst for the four heavy metals in the water-washing fly ash, the chlorination agents obviously affected their volatilization, especially of Zn and Cu, and more than 95% of the four heavy metals were volatilized after spiking chlorination agents.