Evaluation of electro-Fenton method on cheese whey treatment: optimization through response surface methodology

In this study, the efficiency of real cheese whey treatment using a low-cost graphite-graphite electro-Fenton (EF) method and the effects of operating parameters on the process were investigated using central composite design. Response surface methodology was used to evaluate the effect of process variables and their interaction on chemical oxygen demand (COD) removal, energy consumption, and current efficiency. Results show that selected operational parameters and obtained regression models were statistically significant. The coefficient of determination of COD removal, energy consumption, and current efficiency were found as 0.9884, 0.9371, and 0.8479, respectively, indicating that the models have a good fits with experimental data. Optimum operating conditions were determined as 0.0625 mol FeSO4 center dot 7H(2)O, 14.48 H2O2/FeSO4 center dot 7H(2)O molar ratio and 1.22 A current intensity (9.68 mA/cm(2) current density). EF treatment study under optimal conditions yielded 86.75% COD removal and 0.36 kWh/kg CODr energy consumption with 47.11% current efficiency. The results show that the present treatment with the use of low-cost graphite electrodes yielded highly competitive and promising results under low current density conditions.