Effective Electro-Fenton Treatment for a Real Textile Effluent: A Case Study

In this study, a real textile effluent (RTE) was treated by the electro-Fenton method in a parallel plate reactor. A carbon fiber cathode and a stainless-steel mesh anode were used as electrodes. The effluent was characterized, and dilute solutions were prepared with initial chemical oxygen demand (COD) concentrations of 50, 100, 200, 250, and 300 ppm. The prepared effluents were degraded for 180 min, at an applied voltage of 1.8 V and a current density of 0.45 mAcm(-2). Reductions of more than 85 % of the initial color and 55 % of the COD were achieved. The energy consumption was 7 kW h kgCOD(-1) removed. The RTE degradation followed pseudo-first-order kinetics, and its rate constants ranged from 0.01 to 0.02 min(-1). It was observed that the degradation rate decreased as the initial effluent concentration increased. Based on the kinetic results, a methodology was developed to predict the effluent degradation. For each kinetic equation, the empirical constant (a) and the rate constant (k) were determined. Mathematical models were formulated for a and k, relative to their respective CODi concentrations, with a correlation coefficient greater than 0.95 in both cases. The theoretical values of a(t) and k(t) for the working concentrations were calculated using the formulated mathematical models. The theoretical parameters were substituted into the first-order kinetic equation, allowing the simulation of the RTE degradation. The degradation behavior was simulated for each of the five concentrations studied, and the results compared with the experimental results. The theoretical and experimental values showed a high degree of adjustment, demonstrating that the proposed methodology was successful in predicting the degradation of the textile effluent.