Photocatalytic sensor for the determination of chemical oxygen demand using flow injection analysis

A photocatalytic sensor for the determination of chemical oxygen demand (COD) with flow injection analysis (FIA) based on the photocatalysis of organic compounds in the presence of titanium dioxide (TiO2) beads in a photochemical column is described. The sensor was developed in conjunction with TiO2 beads in the photochemical column and with an oxygen electrode as the sensing part. The sensor signal was observed as a result of the detection of dissolved oxygen changes due to photocatalytic oxidation of organic compounds in the sample solution. This sensor responded linearly to the CODMn of artificially treated wastewater (AWW) in the range of 0.12-8ppm. A complete analysis, including sampling and washing, took about 10min. The sensor was stable for over 15 days and has successfully been applied to the determination of COD in lake samples.