Optimization of congo red degradation performance on diatomaceous earth catalyst using Box-Behnken design
Abstract
The degradation of congo red (CR) was investigated in a Fenton-type reaction system with the presence of diatomaceous earth (DE). Response surface methodology (RSM) based on Box-Behnken design was applied to optimize the degradation performance. In these experimental designs, three process parameters affecting the degradation performance, such as initial CR concentration (30 - 50 mg/L), reaction temperature (30 - 50 °C) and degradation time (5 - 45 min), were investigated. The obtained experimental data were fitted into a quadratic polynomial equation using multiple regression analysis with high correlation coefficient value ( R 2 = 0.9999). At an initial CR concentration of 40 mg/L, a reaction temperature of 40 °C, and a reaction time of 14.2 min, the degradation efficiency of 99% was predicted by the model (under the conditions: DE 1.2 g/L, pH 6, H 2 O 2 6.5 g/L). This result was also confirmed through validation experiments, indicating that RSM is one of the effective methods to optimize the operating conditions in this study.