氢化物发生-原子荧光光谱法测定处理废水中砷

研究了氢化物发生-原子荧光光谱法测定砷钙渣固化、高砷烟尘湿法中和、苄基砷酸及仲钨酸铵生产等废水中砷的最佳条件。实验表明,废水样经化学处理，在稀盐酸介质中用硫脲-抗坏血酸将砷预还原为砷，Fe³⁺、Ca²⁺、Na⁺、Cu²⁺、F^-、S^2-、Bi³⁺、Sn⁴⁺、Sb⁵⁺等23 种离子的允许量（mg/50 mL）中高者达250或低至0.5。载液盐酸浓度为5%（V/V）,定量样品与15 g/L硼氢化钾碱性溶液混合生成砷化氢。在选定条件下, 砷量在 2～100 μg/L范围内线性关系良好，检出限（3σ/K）为0.001 4 μg/L。方法用于实际废水样品分析, 相对标准偏差（n=9～11）为1.6%～5.9%,加标回收率在93%～118%之间，固化废水测定值与砷锑钼蓝光度法相符。

Determination of arsenic in treated sewage by hydride generation-atomic fluorescence spectrometry

In this study, the optimum conditions by hydride generation-atomic fluorescence spectrometry for the determination of arsenic content in sewage is reported. The investigation was performed with these sewage including leachate of calcium slag for solidifying arsenic, wet neutralizing solution of high-arsenic dust, sewage of production for benzyl arsenic acid and ammonium paratungstater. Experiment indicated that after the waste water was treated with chemical method, the ions tolerance amount (mg/50 mL) of 23 ions including Fe³⁺，Ca²⁺，Na⁺，Cu²⁺，F^-，S^2-，Bi³⁺，Sn⁴⁺，Sb⁵⁺ was between 0.5 and 250 when the As  was reduced to As  by sulfur urea-ascorbic acid in the medium of dilute hydrochloric acid. The concentration of hydrochloric acid was 5 % (V/V) and the sample was mixed with 15 g/L potassium borohydride alkaline solution to produce arsenic hydride. Under the selected condition, arsenic had an excellent linear relationship when its content was 2-100 μg/L. The detection limit (3 σ/K) was 0.001 4 μg/L.The method was used for the actual waste water analysis with RSD (n=9-11) of 1.6 %-5.9 % and recovery of 93 %-118 %. The determination results of solidification sewage were consistent with those obtained by arsenic antimony molybdenum blue photometric method.