Investigation of different treatment strategies such as membrane filtration and Fenton processes in the treatment of dairy industry wastewater

This study investigated the treatability of dairy industry wastewaters by using the Fenton process and membrane bioreactors. Firstly, the effects of the Fenton process on the reaction time, pH, Fe2+ and H2O2 concentrations on chemical oxygen demand (COD) and total organic carbon (TOC) removal were determined to evaluate the treatment of dairy industry wastewater. According to the results obtained, the optimum reaction time, pH, Fe2+ and H2O2 concentrations were found to be 60 min, pH 3, 1 g/L, 1.5 g/L, respectively, while the COD and TOC removal efficiencies were 87% and 75%. Secondly, biological treatability of wastewater in membrane bioreactors was investigated. The input water COD concentrations of 0.6–2 g/L, sludge age values of 3 h to 10 d and different hydraulic waiting processes were studied. Loading was made to the system at 5 kg COD/m3d, and later, loading was increased up to 17 kg COD/m3d based on the input water COD values. After treatment with membrane bioreactors, the COD removal efficiency varied between 95%–98%. As the output water concentrations obtained as a result of the study satisfied the discharge limits, the applied biological treatment and advanced oxidation methods were completed successfully.