Application of nanofiltration for reuse of wastewater

The present research is a part of efforts to reuse wastewater by applying nanofiltration (NF) method for the secondary treatment of bio-treated wastewater and to check the quality of product water as irrigation water by using various analytical methods. For this, the performances of three different NF membranes (CK, GE-Osmonics; NF-270 and NF-90, Dow-FilmTech) were investigated using a cross-flow flat-sheet membrane test unit (SEPA CF-II, GE). The bio-treated wastewater obtained from ITOB-OSB Wastewater Treatment Plant, Izmir where membrane bioreactor (MBR) technology is employed as a treatment process has a high salinity and a high conductivity which make the treated water unsuitable for irrigation purposes. After applying NF separation for the three membranes at 10 bar as operating pressure, it was concluded that NF-90 gave the best quality of product water for almost all analysed parameters such as salinity calcium, magnesium, sodium, potassium, bicarbonate, chloride, sulphate, phosphate-phosphorous, nitrate-nitrogen, and conductivity.