On-line analysis of copper and zinc in industrial effluents by UV-visible spectrometry

UV-visible spectrometry is used here for on line analysis of heavy metals i n industrial effluents, Heavy metals are analysed by use of a complexing ag ent giving coloured complexes with heavy metals. Unfortunately, the spectra of these complexes are early identical and only powerful multivariate anal ysis algorithm such as Partial Least Square (PLS) must be used in order to determine individual concentrations of 2 or 3 heavy metals in a solution. T he calculation of the residuals of absorbance allows the detection of the e vents not present during the calibration, and so to eventually eliminate wr ong measurements. On an industrial site, a model with the two components, C u and Ni, was used and the main chemical problems which appeared are descri bed and solutions are proposed.