Treatment of tannery effluent using a rotating disc electrochemical reactor

Abstract

The aim of the present research is to degrade organics present in the tannery effluent by electrooxidation method. The work is divided into four modules. The first module addresses the Residence Time Distribution (RTD) in Rotating Disc Electrochemical (RDE) reactor under various operating conditions. The electrolyte flow behavior has been experimented using the pulse input technique. In the second module, the RTD datas obtained from the experiment was used to simulate with computational fluid dynamics (CFD). In this study a 3D model for rotating disc electrochemical reactor has been developed using CFD. Multiple Reference Frame (MRF) approach and the k and#949; turbulence model in combination with species transport model were implemented using ANSYS Fluent 14.0. The flow generated in the reactor with and without impeller rotation has been analyzed. The CFD simulation has been compared with the experimental data on exit age distribution and percentage colour removal. It has been observed that the model predictions satisfactorily match with the experimental data. After extensive analysis on the performance of RDE using CFD, technical feasibility of the improvement in the treatment of tannery effluent by electro oxidation using three fundamental configurations (batch, batch recirculation and once through) has been attempted. Experiments were carried out for color, TOC reduction of tannery effluent, covering a wide range of operating conditions. In the fourth module, the lab scale model is scaled up to pilot scale to check the feasibility of implementing the system in large scale industries. A statistical tool of the Box Behnken method has been used to design the experimental run and optimization. The degradation mechanism was studied by UV Visible spectrophotometer, FT- IR and HPLC, it has been observed that dye house effluent can be effectively treated using the novel electrochemical reactor. Hence, it can be suggested that the novel RDE reactor can be effectively implemented in industries for pollutant treatment. newline newline