کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
639203 1456188 2006 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Effect of salt mixture concentration on fractionation with NF membranes
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی تصفیه و جداسازی
پیش نمایش صفحه اول مقاله
Effect of salt mixture concentration on fractionation with NF membranes
چکیده انگلیسی

Desal-5 DK, NF 270, NF (Dow), NF 20 and ESNA-1-LF nanofiltration membranes were tested for their selectivity, when single and mixed salt solutions (NaCl, NaCl:Na2SO4 1:1 ratio) of different concentrations were filtered at a constant permeate flux. Streaming potential measurements were used to characterise the new NF 20 (Sepro) and NF (Dow) membranes.The membrane surface charge increased the retentions when dilute salt solutions were filtered. The best selectivity was generally achieved using low permeate fluxes and high salt concentrations. At higher salt concentrations the charge effects were diminished. Negative NaCl retention values were obtained for all but the ESNA-1-LF membrane, when concentrated mixed salt solutions were filtered. The use of higher permeate fluxes increased salt retentions in general. The measured isoelectric points (IP) for the NF (Dow) and the NF 20 (Sepro) membranes were 5.1 and 6.6, respectively. Owing to the close proximity of the IP of the NF 20 membrane to the filtration conditions, the effect of the surface charge on the separation was limited and salt fractionation was efficient at all tested salt concentrations. Of the studied membranes, the NF (Dow) and the Desal-5 DK showed the best selectivity. According to the salt retention data, the ESNA-1-LF membrane should not be considered a nanofiltration membrane, but rather a slightly open reverse osmosis membrane.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Membrane Science - Volume 283, Issues 1–2, 20 October 2006, Pages 57–64
نویسندگان
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