Treatment of highly polluted cosmetic wastewater

Three samples of cosmetic wastewater from the production of soaps and shampoos were treated by the following processes: coagulation with sedimentation (C/S), coagulation with dissolved air flotation (C/DAF), and the Fenton process (FP). The COD values of raw wastewater samples were 13 160, 13 580 and 9410 mg O₂/dm³. The anionic surfactants were 3000, 4500 and 4000 mg/dm³, for samples 1, 2, and 3, respectively. All three processes were effective in highly polluted cosmetic wastewater treatment. The most effective process was coagulation. In the case of sample 1, application of FeCl₃ at pH 6.0 resulted in 88.2% of COD removal and the application of aluminum based coagulants allowed for 80.1–85.3% COD removal. In the case of samples 2 and 3, the usage of Al 1019 and Al 3010 coagulants brought about a 91.6% and 82.6% decrease in COD values, respectively. C/DAF was found to be less effective than C/S. The best results with C/DAF were obtained using Al 3010 coagulant with wastewater recirculation the COD removal efficiency amounted to 82.3, 87.3 and 78.8, respectively. The lowest COD removal efficiency was observed for FP and it was equal to 64.0 and 72.7% for samples 2 and 3, respectively.