Factors Influencing the Removal of Fluoride from Groundwater by Nanofiltration

• Main Authors: Ma Wei-fang, Liu Wen-jun, Chen Guo-wei
• Format: Conference Proceeding
• Language: English
• Subjects: Biomembranes; Cleaning; Feeds; Filtration; Noise measurement; Reverse osmosis; Scanning electron microscopy; Teeth; Temperature; Water resources
• ISSN: 2151-7614; 2151-7622
• DOI: 10.1109/ICBBE.2009.5162848

The influence of co-existing chloride, sulfate, pH, and temperature to defluoridation of groundwater using nanofiltration membrane and membrane fouling were studied. The results show that nanofiltration has retention effect to all co-existing ions. When feed fluoride concentration was less than 6 mg/L, the fluoride concentration in permeated water was less than 1.2 mg/L which could reach the drinking water standard in China rural area. The fluoride retention rate decreases with the increase of feed fluoride, co-existing ions concentration or pH. The decreasing percentage of fluoride retention rate is the same when Cl - concentration increased 1 mol or SO 4 2- concentration increased 0.5 mol. The fluoride retention rate increase when feed chloride concentration exceeded 220 mg/L. But the variation had no significant change. The fluoride retention rate increases with the increasing of pH, while there is a milestone on pH 4.4. Environmental scanning electron microscope (ESEM) and its energetic chart analysis apparatus, X-ray Diffration(XRD) analysis show that the main fouling component was CaCO 3 . The fouling membrane could be recovered flux using citric acid and ammonia cleaning method.