TY - GEN
T1 - Competitive sorption and desorption of phenols in surfactant-modified clays
AU - Shin, Won Sik
AU - Kim, Young Kyu
AU - Kim, Ji Hoon
AU - Kim, Young Hun
AU - Jeon, Young Woong
AU - Song, Dong Ik
PY - 2002
Y1 - 2002
N2 - Single- and bisolute competitive Sorption and desorption of phenols in natural clays modified with hexadecyltrimethylammonium (HDTMA) were investigated. Two different types of experiment were conducted: (1) single-step sorption/desorption of phenol and 4-chlorophenol (4-ChP) in HDTMA-bentonite and (2) sequential sorption/desorption of 2,4-dichlorophenol (2,4-DChP) and 2,4,5-trichlorophenol (2,4,5-TChP) in HDTMA-montmorillonite. As expected by the Kow, 4-ChP (log Kow = 2.39) exhibited higher sorption affinity and desorption-resistance than phenol (log Kow = 1.46). This is mainly attributed to stronger hydrophobic interactions between the solute and the pseudo-organic medium formed by HDTMA cation. Sorption and desorption isotherms were nearly identical indicating that sorption of phenols in organoclay mainly occurs via partitioning into the core of the pseudo-organic medium, thereby causing desorption nearly reversible, In the bisolute system, competition between the solutes reduced sorption amount of each solute. The ideal adsorbed solution theory (IAST) coupled to a single-solute Freundlich model successfully predicted the bisolute competitive sorption/desorption equilibria. Effect of pH on the sequential sorption/desorption of 2,4-DChP and 2,4,5-TChP in HDTMA-montmorillonite was investigated. For both chlorophenols, neutral species at pH 4.85 exhibited higher sorption affinity and desorption-resistance than anionic species at pH 9.15. Desorption of chlorinated phenols was nearly reversible at both pHs and strongly dependent on pH of the aqueous phase, regardless of their speciation (neutral or anionic) during sorption stage. The IAST coupled with single-solute Freundlich model successfully predicted bisolute sequential sorption and desorption equilibria.
AB - Single- and bisolute competitive Sorption and desorption of phenols in natural clays modified with hexadecyltrimethylammonium (HDTMA) were investigated. Two different types of experiment were conducted: (1) single-step sorption/desorption of phenol and 4-chlorophenol (4-ChP) in HDTMA-bentonite and (2) sequential sorption/desorption of 2,4-dichlorophenol (2,4-DChP) and 2,4,5-trichlorophenol (2,4,5-TChP) in HDTMA-montmorillonite. As expected by the Kow, 4-ChP (log Kow = 2.39) exhibited higher sorption affinity and desorption-resistance than phenol (log Kow = 1.46). This is mainly attributed to stronger hydrophobic interactions between the solute and the pseudo-organic medium formed by HDTMA cation. Sorption and desorption isotherms were nearly identical indicating that sorption of phenols in organoclay mainly occurs via partitioning into the core of the pseudo-organic medium, thereby causing desorption nearly reversible, In the bisolute system, competition between the solutes reduced sorption amount of each solute. The ideal adsorbed solution theory (IAST) coupled to a single-solute Freundlich model successfully predicted the bisolute competitive sorption/desorption equilibria. Effect of pH on the sequential sorption/desorption of 2,4-DChP and 2,4,5-TChP in HDTMA-montmorillonite was investigated. For both chlorophenols, neutral species at pH 4.85 exhibited higher sorption affinity and desorption-resistance than anionic species at pH 9.15. Desorption of chlorinated phenols was nearly reversible at both pHs and strongly dependent on pH of the aqueous phase, regardless of their speciation (neutral or anionic) during sorption stage. The IAST coupled with single-solute Freundlich model successfully predicted bisolute sequential sorption and desorption equilibria.
UR - http://www.scopus.com/inward/record.url?scp=2342444325&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:2342444325
SN - 1574771329
T3 - Proceedings of the Third International Conference on Remediation of Chlorinated and Recalcitrant Compounds
SP - 397
EP - 404
BT - Proceedings of the Third International Conference on Remediation of Chlorinated and Recalcitrant Compounds
A2 - Gavaskar, A.R.
A2 - Chen, A.S.C.
T2 - Proceedings of the Third International Conference on Remediation of Chlorinated and Recalcitrant Compounds
Y2 - 20 May 2002 through 23 May 2002
ER -