Abstract: “A water-based paint wastewater, generated mainly during a periodic equipment-cleaning, was subjected to the combined pre-coagulation and advanced chemical treatment (H2O2/Fe2+, S2O82-/Fe2+, S2O82-/OH-, or S2O82-/H2O2 system). The results of ferric pre-coagulation trials indicated a high efficacy in wastewater treatment, resulted in 4 and 15 % residual COD and DOC, respectively, and in more than a 10-fold increase in a BOD7/COD ratio. The Fenton treatment of the pre-coagulated wastewater at the optimal COD/H2O2/Fe2+ weight ratio of 1:2:0.4 resulted in respective 14 and 31 % residual COD and DOC. The BOD7/COD ratio increase was the highest at the optimal ratio and resulted in more than 6-fold and 81-fold increase compared to the pre-coagulated and initial wastewater, respectively. The COD and DOC removal remained nearly identical in all trials with the ferrous-ions activated persulfate treatment of the pre-coagulated wastewater and did not exceed 35 and 7 %, respectively. The BOD7/COD re”

Keywords: activated persulfate, coagulation, Fenton process, oxidation, water-based paint wastewater