电位滴定法测定电镀废水中铜含量

Potentiometric Titration Used in the Determination of Copper in Electroplating Wastewater

根据电镀废水中铜（Ⅱ）离子与其他组分化学性质的差异，控制溶液的酸度，以铜离子选择性电极作指示电极，双盐桥饱和甘汞电极作参比电极，以硫化钠标准溶液作滴定剂，采用选择沉淀电位滴定法测定电镀废水中的铜。结果表明：控制溶液pH值1．0～1．5，以氟化铵掩蔽废水中共存的铁（Ⅲ），可以直接用Na2S选择沉淀电位滴定法测定电镀废水中铜的含量。该法不需分离就可直接测定，操作简单，分析速度快，灵敏度高。将本法测定结果与原子吸收分光光度法进行比较，结果无显著性差异。

According to the difference of the chemical properties between Copper （ Ⅱ ） ion and other components in the eleetroplating wastewater, the copper value contained in the selected sample can be measured by means of precipitation Potentiometric Titration by controlling the acidity and temperature of the solution when using Copper ion-selective electrode and double salt bridge saturated calomel electrode as instructive electrode and reference electrode respectively with the titrant of appropriate standard solution. The study shows that： when the PH is controlled in the range from 1.0 to 1.5, the interference of coexistence iron ions （Ⅲ） have been avoided by using NH4F, the contents of copper value Can be directly measured by above mentioned method which is much more simple,faster and supersensitive , also it is unnecessary to separate the coexistence contents in the solution, meanwhile the results have no significant difference when it is compared with AAS.