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A simple sulfuric acid pretreatment method to improve the adsorption of Cr(VI) by chitosan
Author(s) -
Lasko C. L.,
Adams K. H.,
DeBenedet E. M.,
West P. A.
Publication year - 2004
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.20829
Subject(s) - chitosan , sulfuric acid , adsorption , chemistry , chromium , nuclear chemistry , effluent , chromatography , inorganic chemistry , organic chemistry , environmental engineering , engineering
An optimum pH of 5.0 for the adsorption of Cr 6+ by chitosan was determined by using a stirred‐batch reactor method at constant pH. When a column containing chitosan was used to bind Cr 6+ in a situation where pH could not be held constant because of pH changes caused by the chitosan itself, significant binding occurred only at solution pH 1 and 2. When chitosan was pretreated with sulfuric acid in a range of 7–70 mol % sulfuric acid : moles glucosamine residue, maximum binding occurred at pH 6.0. Under these conditions, a column containing 0.500 g acid‐treated chitosan (35% mole ratio) reduced the concentration of Cr 6+ in 713 bed volumes of 25 ppm Cr 6+ solution to ≤5 ppm in the effluent. A similar column of pretreated chitosan reduced Cr 6+ concentration in 1042 bed volumes of industrial chromium plating rinse water initially containing 18 ppm Cr 6+ to ≤5 ppm. Capacity experiment results indicated 60 mg chromium bound per gram of treated chitosan at pH 6.0. Commercial resin IRA‐67 was also investigated as a Cr 6+ binding agent. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2808–2814, 2004