Flow injection and chemometric techniques for the on-line monitoring of industrial liquid effluents
The legal requirement to monitor discharges of harmful substances in industrial waste waters is presented in Chapter One, which also discusses the merits of using automated online analytical instruments for this purpose. Flow injection analysis with solid-state UV-visible detection is proposed as a potential on-line effluent monitoring technique, and the principles and advantages of this methodology are summarised. Chapter Two describes the development of a portable, automated Fl monitor for on-line determination of ammonia in liquid effluents. The development process culminates with deployments of the system at two chemical production sites, and validated results are presented for on-line analyses of real effluents. The principles of multivariate calibration of spectrophotometric data are summarised in Chapter Three, and five commonly applied techniques (DMA, SMLR, PCR, PLSl and PLS2) are described and compared. These multivariate calibration techniques are then applied in Chapter Four for the quantification of metal ions in model eflfluent systems, using diode-array spectral data sets. The relative predictive performances of the techniques are compared for both simple and more complex multicomponent systems.