Acid Red 1 and Acid Red 114 decolorization in H_2O_2-modified subcritical water: process optimization and application on a textile wastewater

摘要

Solutions of Acid Red 1 and Acid Red 114 were treated in H2O2-modified subcritical water in the temperature range of 100 degrees C-200 degrees C for up to 60 min. Response surface methodology based on the Box-Behnken design was used to optimize the process. For Acid Red 1, optimum decolorization of 97% can be achieved at 192 degrees C, 181 mM H2O2, 51.3 min treatment time, and 121 mg/L dye concentration. For Acid Red 114, the optimum conditions were 195 degrees C, 157 mM H2O2, 38 min treatment time and 110 mg/L dye concentration, where 91% decolorization could be obtained from the proposed model. It was determined that temperature is the most important factor, followed by the oxidant concentration. Degradation was less efficient for AR114 due to the double azo bonds, compared to the single azo bond of AR1. Application of the optimum treatment conditions on real reactive dye wastewater resulted in 92.7, 79.1 and 20.4% removal of BOD5, COD and TSS, respectively.