Development of a computer-controlled Fenton's oxidation process

Abstract

Fenton's reaction is one alternative technology in wastewater treatment. In this reaction, the reactive hydroxyl radical (OH•) can easily oxidize many organic molecules. 2,4-dinitrophenol (DNP) was used as a model pollutant in this study. The ratio of concentration of DNP and Fenton's reagent (Fe2+ and H2O2) played an important role in this process, which determined the performance of the reaction. As part of Fenton's reaction, oxygen was produced and consumed by the DNP-OH• radical. Based on observations of dissolved oxygen (DO) during the reaction, a typical DO profile was obtained and it was used to develop a computer-controlled Fenton's oxidation process. Several reaction cycles were conducted in order to monitor the reliability of the control program. The experimental results show that the methods applied in the program could anticipate the trend of the DO curve and effectively handle the variability of the DO data received from the DO meter. The end-point of the Fenton's reaction could be identified by the control system. At the end point, DO concentration began increasing and there was no DNP detected in the solution. From these observations, it was discovered that the DO concentration can reflect the progress of the reaction and it can be used as an parameter for controlling the process.