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Coupling reverse osmosis with electrodialysis to isolate natural organic matter from fresh waters
KOPRIVNJAK, J. F., E. M. PERDUE, AND P. H. PFROMM. Coupling reverse osmosis with electrodialysis to isolate natural organic matter from fresh waters . WATER RESEARCH. Elsevier Science Ltd, New York, NY, 40(18):3385-3392, (2006).
This study was undertaken to solve the problem of removal of sulfate and silica from solutions of natural organic matter (NOM) that have been pre-concentrated by reverse osmosis. The goal is the development of a method by which NOM can be concentrated and desalted to obtain a low-ash, freeze-dried solid material. Current practice yields solutions that, upon desalting and freeze-drying, yield NOM containing finely dispersed sulfuric acid and silicic acid. These acids will contribute to the apparent carboxylic and phenolic contents of NOM, leading to an overestimation of both. NOM may also be chemically altered by sulfuric acid, which reacts strongly with many classes of organic compounds. The sulfur content and ash content of NOM will be elevated in the presence of sulfuric acid and silicic acid. This study evaluates electrodialysis as a method for removal of sulfate and silica from concentrated synthetic river and concentrated (by reverse osmosis) river waters. Under optimal operating conditions, both sulfate and silica can be largely removed without any significant loss of NOM. The electrodialysis process is sufficiently mild that the NOM is not altered by chemical or physical conditions.
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Coupling reverse osmosis with electrodialysis to isolate natural organic matter from fresh waters Exit
Record Details:Record Type: DOCUMENT (JOURNAL/PEER REVIEWED JOURNAL)
Organization:U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
NATIONAL RISK MANAGEMENT RESEARCH LABORATORY
WATER SUPPLY AND WATER RESOURCES DIVISION
TREATMENT TECHNOLOGY EVALUATION BRANCH