巯基棉分离富集ICP-AES法测定高盐冶金废水中痕量铅镉铜银

矿山企业的冶金废水含有多种污染环境的金属元素,必须经过化学沉淀法处理达标后排放。冶金废水经化学沉淀后引入了大量盐分,使得金属元素含量变得极低给分析测试造成困难。针对此类高盐冶金废水,本文采用巯基棉分离富集其中的金属元素,建立了运用电感耦合等离子体光谱(ICP-AES)测定铅、镉、铜、银的分析方法。通过优化实验表明,巯基棉可有效地分离实际样品中大量存在的硫酸根离子和钠离子基体,富集待测元素的效果显著,硫酸根离子和钠离子回收率均小于0.05%,待测元素的回收率在88.7%~113.0%之间。实验条件方面,待测溶液的pH值对巯基棉吸附有较大的影响,使用巯基棉富集前应将溶液调节至适宜的pH值;待测溶液在富集柱中的流速和洗脱剂盐酸的浓度对分离富集效果也有一定的影响。在最佳实验条件下,本法回收率为95.0%~102.0%,精密度(RSD)为3.1%~9.4%,方法快速简便、准确度高,能够满足冶金废水中痕量金属元素的检测需求。

Determination of Trace Amounts of Pb, Cd, Cu and Ag in High Salinity Water by ICP-AES with Sulfhydryl Cotton Separation and Preconcentration

Wastewater from mining enterprises contains a variety of heavy metals, and therefore requires treatment before discharge to render it non-toxic. After treatment by chemical precipitation, the content of metal is extremely low but has a large amount of salt introduced, which increases the difficulty of metal analysis in wastewater. A method for enrichment of trace elements from high salinity wastewater is described in this paper. Pb, Cd, Cu and Ag were determined by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) after separating and enriching with sulfhydryl cotton. Optimization experiment results showed that sulthydryl cotton could effectively separate a large number of sulfate ions and sodium ions, and could obviously enrich trace elements in the actual samples. The recovery rates of sulfate ion and sodium ion were all less than 0.05%, and the recovery rates of test target elements were at the rate of 88.7%-113.0%. Moreover, the effect of pH, flow rate of solution and the concentration of hydrochloric acid were investigated. Under optimal instrument conditions, the recoveries of these elements were 95.0%-102.0% and RSDs were 3.1%-9.4%, respectively. The method is rapid and convenient, with high accuracy and good precision, and should satisfy the analysis of metallurgical wastewater.