Heavy metals leaching in bottom ash and fly ash fractions from industrial-scale BFB-boiler for environmental risks assessment
Heavy metals leaching in bottom ash and fly ash fractions from industrial-scale BFB-boiler for environmental risks assessment
复制标题
DOI：
10.1016/s1003-6326(16)64112-2
复制
发表时间：
2016-01-01
影响因子：
4.5
通讯作者：
Dahl, Olli
中科院分区：
文献类型：
--
作者：
Poykio, Risto;Makela, Mikko;Dahl, Olli
在鼓泡流化床锅炉（296 MW）中，木渣和泥炭共燃产生的底灰和飞灰仅含有石英（SiO2）、微斜长石（KAlSi 3 O 8）和钠长石（NaAlSi 3 O 8）。因此，X射线粉末衍射（XRD）是没有用的澄清相关的重金属从灰基质释放的差异。为了评估在不断变化的环境条件下，从灰烬中释放的重金属，他们依次提取和分馏的BCR程序到酸溶性/可交换的（CH 3COOH），可还原的（NH 2 OH-HCl）和可氧化的（H2 O2/CH 3COONH 4）相。使用CH 3COOH可浸提部分和总重金属浓度计算灰基质中重金属浸出的风险评估代码值。浸出研究表明，底灰和飞灰中的重金属以不同的强度结合到不同的组分中。从环境和利用的角度来看，灰渣中的重金属对环境造成了不同程度的污染风险。只有底灰中的砷才有很高的风险。高风险金属是底灰中的Cd以及飞灰中的As、Cd和Se。
The bottom ash and fly ash from the co-combustion of wood residues and peat at a bubbling fluidised bed boiler (296 MW) contained only quartz (SiO2), microcline (KAlSi3O8) and albite (NaAlSi3O8). Thus, X-ray powder diffraction (XRD) was not useful for clarifying the difference in the release of associated heavy metals from ash matrices. In order to assess the release of heavy metals from ashes under changing environmental conditions, they were sequentially extracted and fractionated by the BCR-procedure into acid soluble/exchangeable (CH3COOH), reducible (NH2OH-HCl) and oxidizable (H2O2/CH3COONH4) phases. The CH3COOH extractable fraction in conjunction with the total heavy metals concentrations were used to calculate the risk assessment code values for heavy metals leaching from the ash matrix. The leaching studies indicate that the heavy metals in the bottom ash and fly ash are bound to different fractions with different strengths. From the environmental and utilization perspectives, heavy metals in ashes posed different levels of environmental contamination risk. Only As in the bottom ash posed a very high risk. High risk metals were Cd in the bottom ash as well as As, Cd and Se in the fly ash.