Abstract In this paper, degradation of Direct Blue 71 (DB71) by Fenton’s oxidation process was
investigated. The effect of initial pH, dosages of Fe2+ and H2O2, dye concentration and temperature
on the color and Chemical Oxygen Demand (COD) removal was studied in a batch reactor. The optimal
conditions for the decolorization and COD removal of DB71 were determined as pH = 3.0,
Fe2+= 3 mg L1 and H2O2= 125 mg L1. Under the optimal conditions 94% color and 50.7%
CODremoval efficiency of the dye in 100 mg L1 aqueous solution were achieved after 20 min of reaction.
Results indicated that the removal efficiency was strongly dependent on initial pH, initial concentration
of Fenton’s reagents, initial DB71 concentration and reaction temperature. Additionally
increasing the reaction temperature from 20 to 60 C showed a positive effect on the decolorization
efficiency of DB71. The experimental data were analyzed using the first and second-order and Behnajady–
Modirshahla–Ghanbery (BMG) kinetic models.BMGmodel provides the best correlation of the
data. The present study can provide guidance to relational industry operators and planners to effectively
treat the DB71 contaminated wastewater by Fenton’s oxidation process.