Application of Tetraphenyl- and Ethyltriphenylphosphonium Salts for Separation of Reactive Dyes from Aqueous Solution

Abstract

The decolorization efficiency of four anionic dyes dissolved in aqueous solution using two quaternary phosphonium salts, ethyltriphenylphosphonium bromide, and tetraphenylphosphonium bromide, has been investigated by spectroscopic measurements in neutral, acidic and basic media. The NMR studies suggest possible formation of ion pairs of tetrasubstituted phosphonium salts with the reactive dyes. According to the results, the tetraphenylphosphonium bromide, which contains a more hydrophobic and bulky cation, exhibited a stronger tendency to associate with the dyes.

Keywords:

• ¹H and ³¹P NMR spectroscopy
• anionic dye
• cationic surfactant
• precipitation
• wastewater treatment

ACKNOWLEDGEMENTS

This work was supported by the Technology Agency of the Czech Republic (Grant No. TA01010606) and Ministry of Education, Youth, and Sports of the Czech Republic (project No. MSM 0021627502).

Notes

*The spectra are calibrated on H₃PO₄ as an external standard δ(H₃PO₄) = 0 ppm.