Evaluation of operational parameters and its relation on the stoichiometry of Fenton’s oxidation to textile wastewater

The operation conditions for the implementation of the Fenton process are of utmost importance because there are problems related to the proportion of H₂O₂ dosage to COD and Fe²⁺ dosage to the specified H₂O₂ amount. The relevant lite-rature shows that COD/H₂O₂ ratios range between 0.0084 and 113.9. Similarly, the COD/Fe²⁺ ratio varies between 0.079 and 292.6, while the H₂O₂/Fe²⁺ ratio varies between 0.09 and 287. Moreover, the ratio of the maximum value to the minimum value used in the operations on the basis of COD is 13560 for COD/H₂O₂ (0.0084-113.9), 2210 for COD/Fe²⁺ (0.079-174.7), and finally 3190 for H₂O₂/Fe²⁺ (0,09-287). The aim of this study was to re-evaluate these values that significantly differ from each other with specific emphasis on textile wastewater and considering stoichiometric ratios. Results showed that values ranging between 0.43 and 4.0 for COD/H₂O₂ and those ranging between 0.75 and 3.0 for H₂O₂/Fe²⁺ are more suitable. The results showed that in a Fenton process con-ducted by dosing H₂O₂ at different times, the TOC reduction efficiencies inc-reased from 80.8 up to 88.9%. Similarly, the color reduction efficiency also rose from 96.5 to 98.7%.