Removal of COD from Oil Recovery Industry Wastewater by the Advanced Oxidation Processes(AOP) Based on H2O2

The combinations of H2O2/Fe+2, UV/H2O2/Fe+2 and UV/H2O2 process were investigated on
treatment of oil recovery industry wastewater. Treatment of oil recovery industry wastewater,
a typical high pollution strength industrial wastewater (chemical oxygen deman (COD): 21000
mg l-1, biological oxygen demand (BOD): 8000 mg l-1, oil and grease:1140 mg l-1, total
dissolved solids (TDS): 37000 mg l-1, total suspended solids: 2580 mg l-1), was carried out by
batch oxidation processes.
The optimal mass ratio for H2O2/Fe+2 yielding the highest COD removal was found to be 8.658
corresponding to 200.52 g 1-1 H2O2 and 23.16 g l-1 Fe+2 concentrations for 60 minutes
reaction time. Fenton process gave a maximum COD reduction of 86% (from 21000 to 2980
mg l-1) and the combination of UV/H2O2 gave a COD reduction of 39% (from 21000 to 12730).
The percentage of removal, after the total reaction time (3.5h), H2O2: 8.4 g l-1 and Fe+2: 0.05g
l-1, in the photo Fenton process, corresponded to 81 % of the total initial COD (4200 mg l-1).
The oxidative ability of the UV/Fe+2/H2O2 process (81%) was greater than that of the UV/H2O2
process (55%) for 80% diluted wastewater. COD removal efficiency for UV/H2O2 process
(COD/H2O2=1/2 (w/w)) was 90%, 55%, and 39 when initial COD was 1050, 4200, and 21000
mg l-1, respectively, whereas COD removal was 943, 2320, and 8270 mg l-1, respectively.