火焰原子吸收光谱法在分析污泥焚烧飞灰中重金属化学形态上的应用

来源期刊：冶金分析2011年第3期

论文作者：刘敬勇 孙水裕

文章页码：17 - 22

关键词：火焰原子吸收光谱法； 微波消解； 污泥焚烧飞灰； 重金属； 化学形态

Key words：flame atomic adsorption spectrometry(FAAS)； microwave digestion； sludge incineration fly ash； heavy metal； chemical speciation

摘    要：应用微波消解-火焰原子吸收光谱法(FAAS)测定污泥焚烧飞灰中的Cd、Cr、Cu、Mn、Ni、Pb、Zn等各重金属元素总量。研究发现,样品用HNO3-HF混合酸经微波消解后,溶解时间由原来的3~5 h缩短到30 min。选择合适的分析谱线,用FAAS直接测定试液中上述7种重金属元素各自总量及其不同形态含量,所得各元素的线性相关系数均大于0.999 0。分析结果表明,污泥焚烧飞灰中重金属Zn,Pb,Mn含量较高,而Ni的含量较低;污泥焚烧飞灰中含有的重金属除Cr相对比较稳定外,其它重金属元素的不稳定态所占比例均很高。处置污泥焚烧飞灰时应选择不同的处置和利用方式,尽可能地将污泥焚烧飞灰中重金属的化学形态由不稳定态转变为稳定态。

Abstract: A novel method was developed to determine the content of seven heavy metal elements including Cd,Cr,Cu,Mn,Ni,Pb and Zn in sludge incineration fly ash by microwave digestion-flame atomic adsorption spectrometry (FAAS).It was found that when the sample was digested by microwave in HNO3-HF mixed acid,the dissolution time decreased from 3-5 h to 30 min.By selecting proper analytical lines,the content of each heavy metal and its different chemical speciation were directly determined by FAAS.The linear correlation coefficient of elements were all higher than 0.999 0.The analytical results indicated that the content of Zn,Pb and Mn in fly ash was high,while the content of Ni was low.Cr in sludge incineration fly ash was relatively stable.However,the proportion of instable states of other heavy metals was high.During the treatment of sludge incineration ash,different disposing and utilization methods should be selected to transform the chemical speciation of heavy metals from instable state to stable state as far as possible.