Development of an amperometric sensor for the continuous and in-line measurement of hydrogen peroxide concentration in textile bleaching baths

Abstract

An amperometric sensor has been developed which is capable of measuring hydrogen peroxide concentrations in an in-line and continuous way with high precision and accuracy (errors do not exceed 2%). The sensor is operational in a concentration range from 3.5 × 10–3 g l–1 (= 1 × 10–4 mol l–1) up to 70 g l–1 (= 2 mol l–1) of hydrogen peroxide. The sensor is positioned directly in the process solution (in-line measurement) and has a very short response time which offers the possibility of automating the process. Besides the possibility of continuous measurements, short response time and high accuracy, the excellent stability of the sensor as a function of time is one of the main advantages in comparison with existing techniques. Successful industrial implementation is obtained in processes with pH >11 (bleaching of textiles, synthesis of organics and inorganics). For processes occurring at lower pH values the sensor has to be supplemented with a FIA system.