ABSORPTION SPECTROSCOPY IN THE VISIBLE SPECTRAL RANGE OF TRIVALENT AND HEXAVALENT CHROMIUM IN DISTILLED WATER AND IN BUFFERS AT DIFFERENT pH VALUES

ABSTRACT

An exhaustive absorption spectroscopy study of both Hexavalent and Trivalent Chromium solutions in distilled water and in buffers in the acid range was carried out. Solutions in the wide 26 µg/L–520 mg/L concentration range were analysed in the visible spectral range by means of a conventional dual beam spectrophotometer equipped with 10 mm and 100 mm path length cuvettes in order to settle the minimum detectable concentration and the saturation limit.

Chromium detection at low concentration is of interest in environmental monitoring because of its carcinogenic risk, while high concentration monitoring is of interest in industrial process control, especially during sewage collection and recycling processes.

The presented absorption spectroscopy study was addressed to the implementation of an optical instrumentation for on-line Chromium detection making use of current optical fibre technology.

Keywords:

• Trivalent Chromium
• Hexavalent Chromium
• Absorption spectroscopy
• Optical fibres

ACKNOWLEDGMENTS

The EU INCO-DC Programme is acknowledged for its financial support of the present work, which was carried out within the framework of the “RAMFLAB” Project (#ERBIC18CT970171).