Extraction of Azo Dyes from Aqueous Solutions with Room Temperature Ionic Liquids

In this work, ionic liquids/water distribution ratios (D) of azo dyes, including 1-(phenylazo)-2-naphthol, 1-(2-pyridylazo)-2-naphthol, 4-(nitrophenylazo)resorcinol, 4-(2-pyridylazo) resorcinol, and 2-(4-dimethylaminophenylazo) benzoic acid, have been determined experimentally. It was found that the D values are highly influenced by the pH of the water phase and the type of salts added. They increase with increasing alkyl chain length on the cations of the ionic liquids, and the anionic effect follows the order [BF4]− > [PF6]−. Possible extraction mechanism and selective separation of some azo dyes are also investigated. The results suggest that ionic liquids have potential applications in the removal and selective separation of azo dyes from water.

[1]  A. Berthod,et al.  Ionic liquids in separation techniques. , 2008, Journal of chromatography. A.

[2]  M. Valcárcel,et al.  The roles of ionic liquids in sorptive microextraction techniques , 2010 .

[3]  M. Goto,et al.  Solvent extraction and stripping of silver ions in room-temperature ionic liquids containing calixarenes. , 2004, Analytical chemistry.

[4]  C. Poole,et al.  Extraction of organic compounds with room temperature ionic liquids. , 2010, Journal of chromatography. A.

[5]  Jing Fan,et al.  Solvent extraction of selected endocrine-disrupting phenols using ionic liquids , 2008 .

[6]  Jing Fan,et al.  Factors affecting ionic liquids based removal of anionic dyes from water. , 2007, Environmental science & technology.

[7]  B. Kirchner,et al.  The role of hydrogen atoms in interactions involving imidazolium-based ionic liquids , 2010 .

[8]  G. Guebitz,et al.  Degradation of Azo Dyes by Laccase and Ultrasound Treatment , 2005, Applied and Environmental Microbiology.

[9]  A. Ball,et al.  Contributions to a better comprehension of redox-mediated decolouration and detoxification of azo dyes by a laccase produced by Streptomyces cyaneus CECT 3335. , 2010, Bioresource technology.

[10]  I. Pletnev,et al.  Solvent extraction of amino acids into a room temperature ionic liquid with dicyclohexano-18-crown-6 , 2004, Analytical and bioanalytical chemistry.

[11]  John Aurie Dean,et al.  Lange's Handbook of Chemistry , 1978 .

[12]  M. Stastna,et al.  New azo dyes as colored isoelectric point markers for isoelectric focusing in acidic pH region , 2005, Electrophoresis.

[13]  D. Macfarlane,et al.  Extraction and recovery of azo dyes into an ionic liquid. , 2006, Talanta.

[14]  D. Armstrong,et al.  Ionic liquids in separations. , 2007, Accounts of chemical research.

[15]  H. Tsunekawa,et al.  Solvation and Ion Association Studies of LiBF4−Propylenecarbonate and LiBF4−Propylenecarbonate−Trimethyl Phosphate Solutions , 2003 .

[16]  Jing-fu Liu,et al.  Ionic liquids in sample preparation , 2009, Analytical and bioanalytical chemistry.

[17]  Wenguo Xu,et al.  Study on the extraction of dyes into a room-temperature ionic liquid and their mechanisms , 2007 .

[18]  Igor V. Pletnev,et al.  Solvent extraction and extraction–voltammetric determination of phenols using room temperature ionic liquid , 2005, Analytical and bioanalytical chemistry.

[19]  Hian Kee Lee,et al.  Analysis of aromatic amines in water samples by liquid-liquid-liquid microextraction with hollow fibers and high-performance liquid chromatography. , 2002, Journal of chromatography. A.