城市生活垃圾焚烧灰渣酸消解方法的确定和优化

Determination and Optimization of Acid Digestion Methods for Municipal Domestic Waste Incinerator Residues

不同基质、不同元素所适用的消解方法不一定相同,选择合适的消解方法和步骤对于得到焚烧灰渣中真实的金属含量有重要的意义。在对已有的焚烧灰渣及相似基质的消解方法进行综合分析后确定了5种不同强度的酸消解方法,分别对飞灰和炉渣进行消解实验,通过比较寻求最佳消解方案。实验结果表明:飞灰和炉渣中除K、Na、As和Hg外的其它金属元素测定,宜采用HCl/HNO3/HF/HClO4消解法;K和Na的测定,宜采用HF/AR(王水)/H2O2消解法;飞灰中Hg和As的测定,宜采用HNO3/H2O2/HCl消解法;而测定炉渣中的Hg和As,则宜采用HF/AR/H2O2消解法。

The appropriate digestion methods vary with dif-ferent matrixes and metals have been analyzed. Choosinga suitable digestion method and process is of greatimportance for getting “true total” metals. Based onanalyses of available acid digestion methods for mu-nicipal domestic waste incinerator residues and similarmatrixes, five processes with different digestion inten-sities were conducted to determine the optimal aciddigestion scheme for metals in air pollution controlsystem (APC) residues and bottom ash respectively. Itwas concluded that HCl/HNO3/HF/HClO4 digestioncould be used for most metals except K, Na, As andHg in both APC residues and bottom ash, while HF/AR (aqua regia)/H2O2 digestion for K and Na in thetwo ash streams, HNO3/H2O2/HCl digestion for Hgand As in APC residues, HF/AR/H2O2 digestion forHg and As in bottom ash.