Possible control approaches of the Electro-Fenton process for textile wastewater treatment using on-line monitoring of DO and ORP

The Electro-Fenton (E-Fenton) process combines the advantages of electrochemical and Fenton processes, which is an effective and popular advanced oxidation process (AOP) for treating textile wastewater. Dynamically regulating the E-Fenton process is still difficult; however, it is critical for reducing operation costs and enhancing process performance. This paper presents the potentials of on-line monitoring of Oxidation Reduction Potential (ORP) and Dissolved Oxygen (DO) as key parameters to control the E-Fenton process for textile wastewater treatment. Experimental results have shown that the monitored DO and ORP profiles have high correlations with the trends of H2O2, Fe+2 and Fe+3 variations, which can help to identify over-dosing of H2O2. Both the multiple regression and the Artificial Neural Network (ANN) models were applied to predict the required Fe+2 doses using the monitoring ORP, DO, and COD removal targets. Very precise prediction results with the correlation coefficients (R-2) of 0.95-0.99 were performed by the multiple regression models and the ANN models, respectively. As a result, the monitoring of DO and ORP have high potentials to effectively control the E-Fenton and contribute to the benefit of chemical cost savings. (C) 2012 Elsevier B.V. All rights reserved.