差分脉冲伏安法对生物冶金中铜(II)的在线检测(英文)

On-line detection of Cu(II) in bioleaching system by anodic stripping differential pulse voltammetry

采用差分脉冲阳极伏安法实现生物冶金中铜(II)浓度的在线检测。结果表明,当体系中仅有铜(II)存在且其浓度范围为1μmol/L～1 mmol/L时,差分脉冲阳极伏安法所测阳极氧化峰电流与浓度间有很好的线性度。当此体系中含有0.2 mol/L KCl时,铜离子检测的线性范围从1 mmol/L(64 mg/L)扩展到100 mmol/L(6.4 g/L)。在此条件下,二价铜离子的还原分为两步连续的单电子转移过程,中间态为Cu+的络合物CuCl-。此外,在铜的生物冶金体系中,经常会有铁离子存在,因此对铜离子检测的铁离子干扰也进行了研究,结果表明,当铁离子浓度低于100 mmol/L(5.6 g/L)时,其对铜离子检测的干扰可忽略。

On-line Cu （II） ion concentration detection in bioleaching system was achieved by anodic stripping differential pulse voltammetry （ASDPV）. Good linearity between Cu （II） concentration and oxidation peak current was obtained when Cu （II） existed in 0K media in the concentration range of 1μmol/L （64μg/L） to 1 mmol/L （64 mg/L）. Moreover, when 0.2 mol/L KCl was added into this media, the linear detection range could be extended from 1 mmol/L to 100 mmol/L （6.4 g/L）. The reduction of Cu （II） to metallic copper was shown to proceed as two successive single-electron transfer reactions involving an intermediate chemical step where the cuprous ion （Cu＋） was complexed by chloride to form the dichlorocuprous anion （CuCl-）. In addition, interference effect was also investigated when Fe3＋existed in the media, which was the common situation in the copper bioleaching system. The results showed no interference effect once the concentration of Fe3＋was less than 100 mmol/L （5.6 g/L）.