Application of membrane processes for the treatment of high strength wastewaters

In the content of this PhD thesis, membrane processes, such as microfiltration, ultrafiltration and nanofiltration were applied for the treatment of cheese whey effluents and olive oil mill wastewaters. Before membrane processes, different physical and chemical pretreatment experiments were done in order to avoid membrane fouling. In this respect, this thesis is composed of two main parts. In the first part of the experimental studies, cheese whey effluents were examined. Maximum removal efficiencies were obtained by combination of physical pretreatment, microfiltration and ultrafiltration processes. 99 percent of SS reduction and 98 percent of oil and grease reduction were achieved. However, COD concentration was as high as 22000 mg/L with 66 percent removal efficiency. In the second part of this thesis, treatment of olive oil mill wastewater (OMWW) was investigated. If chemical coagulation with H2SO4 at pH=2, cartridge filter and filter cloth filtration, ultrafiltration and then nanofiltration processes were applied, 3700 mg/L, 1083 mg/L, 30 mg/L, and 40 mg/L concentrations were achieved for COD, TOC, SS, oil and grease, respectively. With another OMWW sample, application of two step pH adjustment and cartridge filter filtration, and then nanofiltration process gave 1600 mg/L, 948 mg/L, 40 mg/L, 80 mg/L concentrations for COD, TOC, SS and oil and grease parameters, respectively. The results obtained show that NF treatment is a possible and acceptable method for treatment of olive oil mill wastewater.