Evaluation of Efficiency Nitrate Removal of a Nanofiltration Membrane from Drinking Water under Different Operating Conditions

• Main Authors: Ali Torabian, Mehri Shokouhi Harandi, Gholamreza Nabi Bidhendi, Aliasghar Ghadimkhani, Mehdi Safaefar
• Format: Article
• Language: English
• Published: Water and Wastewater Consulting Engineers Research Development 2007-03-01
• Series: آب و فاضلاب
• Subjects: Nanofiltration; Nitrate; Operating Pressure; Ion Compound
• Online Access: http://www.wwjournal.ir/article_1813_c59df9a087a465821363133144ebbc46.pdf
• ISSN: 1024-5936; 2383-0905

The aim of present work was to investigate effects of the water pressure and ion compound present in water to be treated on nitrate removal efficiency of a nanofiltration membrane. Experiments were performed using sodium salts (NaNO3, Na2SO4, NaF), KNO3, Ca(NO3)2, and Mg(NO3)2 added to tap water. The effects of operating pressures were investigated for a pressure range of 4-10 bars for a nitrate concentration of 150 mg.L-1(NO3-). The effects of concentration levels were studied for the levels 50, 100, 150, 200, 250 and 300 mg.L-1(NO3-). Finally,the effects of anions were investigated for concentration levels of 50, 100, 150, 200 and 250 mg.L-1 of F- and SO42-. The results showed that nitrate removal increased with increasing pressure by up to 8 bars beyond which removal goes steady. Increased nitrate salt concentrations in monovalent salts led to reduced nitrate removal but in divalent salts led to increased nitrate removal. The effect of associated cation on nitrate removal was observed to be higher in the case of NaNO3 compared to KNO3. It was further observed that increasing sulfate ion concentrations reduced nitrate removal while increasing fluoride levels increased nitrate removal.