Speciation studies of nickel and chromium in wastewater from an electroplating plant

Jackson K. Kiptoo, J. Catherine Ngila, Gerald M. Sawula

Research output: Contribution to journalArticlepeer-review

39 Citations (Scopus)

Abstract

A speciation scheme involving the use of flame atomic absorption spectrometry (FAAS) and differential pulse adsorptive cathodic stripping voltammetry (DPAdCSV) techniques was applied to studies of nickel and chromium in wastewater from a nickel-chrome electroplating plant. Dimethylglyoxime (DMG) and diethylenetriaminepentaacetic acid (DTPA) were employed as complexing agents for adsorptive voltammetric determination of Ni and Cr, respectively. Cr(III) and Cr(VI) were determined by exploiting differences in their reactivity towards DTPA at HMDE. Total dissolved metal content was in the range 2906-3141 and 30.7-31.2 mg l-1 for Ni and Cr, respectively. A higher percentage of the metal was present as labile species (mean value of 67.9% for Ni and 79.8% for Cr) suggesting that strongly binding ligands are not ubiquitous in the sample. About 77.8% of Cr was found to exist in the higher oxidization state, Cr(IV). Results on effect of dilution on lability of the metal forms in the sample using DPAdCSV showed slight peak shifts to a more negative (cathodic) value by -0.036 V for Ni and -0.180 V for Cr with a dilution factor of 100, while peak intensity (cathodic current) remained fairly constant.

Original languageEnglish
Pages (from-to)54-59
Number of pages6
JournalTalanta
Volume64
Issue number1
DOIs
Publication statusPublished - 8 Sept 2004
Externally publishedYes

Keywords

  • Adsorptive stripping voltammetry
  • Electroplating plant wastewater
  • Labile forms
  • Metal speciation

ASJC Scopus subject areas

  • Analytical Chemistry

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