垃圾焚烧飞灰浸出液中盐分对ICP测定铅和镉的影响

Effect of salt in MSWI fly ash leachate on test of Pb and Cd by ICP

为了探究ICP和AAS测定同一垃圾焚烧飞灰浸出液中Pb、Cd元素存在显著差异的原因,进行了APDC-MIBK萃取和硝酸消解对比实验研究和盐分添加实验研究。研究结果表明：飞灰浸出液中高浓度的盐分是造成ICP和AAS测定结果存在巨大差异的主要原因;当溶液中K^＋、Na^＋、Ca^2＋和Mg^2＋质量浓度分别≥2 600、390、360和1 300 mg/L时,将对ICP测定Pb、Cd产生显著负干扰;APDC-MIBK萃取飞灰浸出液中Cd、Pb的加标回收率在96%-102%之间,可将飞灰浸出液中Pb、Cd元素与盐分分离,因此可作为垃圾焚烧飞灰浸出液前处理方法。

To study the significant differences between the tested concentrations of Pb and Cd in leachate of municipal solid waste incineration fly ash（ MSWI） using inductively coupled plasma（ ICP） and atomic absorption spectroscopy（ AAS）,an ammonium pyrollidine dithiocarbamate（ APDC）-methyl isobutyl ketone（ MIBK）extraction and nitric acid digestion contrast test experiment and a salt-adding experiment were conducted. The results indicated that such differences could be related to the high concentrations of salts in the leachate of MSWI.Significant negative interference in the testing of Pb and Cd in MSWI leachate was observed when the concentrations of K^＋,Na^＋,Ca^2 ＋,and Mg^2 ＋in solution were equal to or higher than 2 600,390,360,and 1 300 mg /L,respectively. The addition standard recoveries of APDC-MIBK extraction for Cd and Pb in the leachate of MSWI were 96% to 102%. The separation of Pb and Cd from the salts in the leachate of MSWI could be used as a pretreatment method for the determination of Pb and Cd in MSWI leachate.