Synergistic retention of heavy metals and in-situ reduction of NO and SO2 by co-combustion of sewage sludge and coal gangue: A promising approach for contaminant management and emission reduction
Synergistic retention of heavy metals and in-situ reduction of NO and SO2 by co-combustion of sewage sludge and coal gangue: A promising approach for contaminant management and emission reduction
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DOI：
10.1016/j.fuproc.2023.107984
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发表时间：
2023-12
影响因子：
7.5
通讯作者：
Jingchong Yan;Yasen Wu;L. Zhang;Shunjin Huang;Z. Lei;Zhanku Li;Weidong Zhang;S. Ren;Zhicai Wang;H. Shui
中科院分区：
文献类型：
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作者：
Jingchong Yan;Yasen Wu;L. Zhang;Shunjin Huang;Z. Lei;Zhanku Li;Weidong Zhang;S. Ren;Zhicai Wang;H. Shui
本研究旨在评价城市污水污泥与煤矸石在800~1000℃下混烧对NO、SO2和重金属(HMS)等污染物排放的影响。结果表明，当污泥比例大于60%时，共燃可使燃烧更加平稳(着火温度和燃尽温度较低，综合燃烧指数较高)，活化能降低约30kJ/mol。此外，主要矿物(尤其是石英(SiO_2)、黄长石(AlPO_4)、钙辉石(CaFeSiO_2O_6)、磁铁矿(Fe_3O_4)和硅灰石(Ca2Al_2SiO_7)与HMS的混烧反应显著提高了HMS在灰烬中的保留率，使HMS含量增加了1~3倍。在900℃以上和850℃以下的混燃过程中，分别观察到了原位硫化和脱氮现象。灰烬中的辉石、白锁石(Ca2.86Mg0.14(PO4)2)和透辉石(CaMgSi2O8)与SO2的析出有关。这些调查结果表明，多种废物混烧是一种可行的办法，既可以利用多种废物，又可以减少固体废物处置对环境的影响。
This study aims to evaluate the influence of co-firing municipal sewage sludge with coal gangue at 800–1000 °C on the emissions of pollutants such as NO, SO2and heavy metals (HMs). The results revealed that co-combustion resulted in smoother combustion (e.g., lower ignition and burnout temperatures, and a higher comprehensive combustion index) as well as a reduction in activation energy by approximately 30 kJ/mol when the sewage sludge ratio was above 60%. Moreover, the retention of HMs in the ashes during co-combustion was significantly improved through reactions between the dominant minerals (especially quartz (SiO2), berlinite (AlPO4), hedenbergite (CaFeSi2O6), magnetite (Fe3O4) and gehlenite (Ca2Al2SiO7) with HMs species presented in the wastes, leading to an increase in HMs content by 1 to 3 times. Additionally,in-situdesulfurization and denitration were observed during co-combustion at above 900 °C and below 850 °C, respectively. It is likely that berlinite has a direct impact on NO emissions, while gehlenite, whitlockite (Ca2.86Mg0.14(PO4)2) and diopside (CaMgSi2O8) present in the ashes are associated with the evolution of SO2during co-combustion. These findings suggest that co-combustion of multiple wastes is a feasible approach for their resource utilization while reducing the environmental impacts associated with solid waste disposal.