IN-LINE, TITANIUM DIOXIDE-CATALYSED, ULTRAVIOLET MINERALIZATION OF TOXIC AROMATIC COMPOUNDS IN THE WASTE STREAM FROM A FLOW INJECTION-BASED RESORCINOL ANALYSER

摘要

A clean method was developed for the spectrophotometric determination of resorcinol. The method, based on the reaction between resorcinol and p-aminophenol (PAP), carried out in a flow system, involves an additional detoxification step based on the in-line TiO2-catalysed photodegradation of the indophenol dye formed and the remaining unreacted PAP. For this, after the measurement step the waste stream is merged with a TiO2 slurry (0.5 g l(-1) in 0.22 mol l(-1) HCl) and then passed through a UV photochemical reactor consisting of a PTFE tube (6 m x 0.8 mm i.d.) rolled on a UV lamp with a maximum irradiation wavelength of 254 nm. Under these conditions, the waste can be completely detoxified thus, providing a non-polluting method of analysis. [References: 22]