The applicability of Fenton and photo-Fenton processes as a pretreatment stage to combined wastewater was investigated. The wastewater was obtained from the inlet of the aeration tank in 42 Evler industrial and domestic wastewater treatment plant. The effects
of different process variables such as initial Fe2+ (c0 = 8-33 mmol L–1) and H2O2 (c0 = 65-165 mmol L–1) concentrations, pH (3-7.75) and reaction time (t = 5-180 min) were evaluated. The Fenton process was investigated which under the operating conditions
(pH 3, cFe2+ = 12 mmol L–1, cH2O2 = 130 mmol L–1) 100 % color and 44 % total organic carbon (TOC) removal were achieved. However, 71 % TOC removal was achieved at pH 7.75 by coagulation but color was poorly removed (c = 20 mmol L–1
Fe2+, c = 165 mmol L–1 H2O2). In the photo-Fenton process, 84 % TOC and 87 % color removal were achieved in 30 min reaction time (pH 3, cFe2+ = 26 mmol L–1, cH2O2 = 130 mmol L–1)
