کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
643393 884370 2009 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
In-line coagulation/ultrafiltration for silica removal from brackish water as RO membrane pretreatment
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی تصفیه و جداسازی
پیش نمایش صفحه اول مقاله
In-line coagulation/ultrafiltration for silica removal from brackish water as RO membrane pretreatment
چکیده انگلیسی
Brackish water with a silica concentration of 30 mg/L as SiO2 was studied for silica removal using in-line coagulation/ultrafiltration (UF) processes to prevent scaling problems in a reverse osmosis (RO) membrane treatment plant. Other than pH and coagulant dosage, mixing intensity and velocity gradient are also a critical factor with respect to silica removal. Different velocity gradient (G), pH and alum dose were experimented and contour plots were used to determine the optimum silica removal. The optimum silica removal of 65% was achieved with G = 2000 s−1, pH = 7.1 and alum dosage = 30 mg/L as Al2O3, corresponding to a maximum of 87% recovery for the RO membrane plant. Silica was removed by co-precipitation of aluminum hydroxide, supported by the results of turbidity and silica measurement. Although the optimum G value to reduce the membrane fouling potential was 1000 s−1, G value of 2000 s−1 can serve the purposes of silica removal with lower fouling potential for this UF membrane. Streaming potential by electrokinetic analyzer was used to analyze the UF membrane before and after filtration, and a slight reduction of negative charge was observed at medium pH, resulting from the adsorption of positively charged coagulated particles on the negatively charged UF membrane surface. energy dispersive X-ray spectroscopy also showed a slight aluminum and silica signal on the used UF membrane surface.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Separation and Purification Technology - Volume 70, Issue 1, 19 November 2009, Pages 112-117
نویسندگان
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