疏水性离子液体萃取脱色水溶性染料实验研究

Decolorization of Soluble Dyes by Extraction Using Hydrophobic Ionic Liquid [Bmim]PF_6

初步研究了疏水性离子液体[Bmim]PF6对6种水溶性染料的萃取脱色性能.结果表明,离子液体对酸性染料平均萃取脱色率超过95%,弱酸性染料64.9%,活性染料18.5%.离子液体染料萃取的pH响应模式随染料结构不同而变化,当废水pH由1.5增至12.5时酸性黄RN萃取脱色率由99.8%减至13.4%;弱酸性艳蓝RAWL萃取脱色率基本不随pH变化;活性黑KN-G2RC pH 5.5时,萃取脱色率为最佳.温度升高染料萃取脱色率随之升高.冠醚加入可提高了离子液体对活性染料的萃取脱色,活性黑KN-G2RC和活性黄M-5R分别由加入前的31.5%和5.5%提高到81.6%和82.7%.

Extraction of dyes into hydrophobic ionic liquid-[ Bmim] PF6 is investigated. The ionic liquid extraction system is successfully used in the extraction of dyes. The effects of some parameters, such as the extraction phase ratio, pH of the aqueous phase, system temperature and the addition of dicyclohexyl-18-crown-6 in organic phase are studied in detail. Acid dyes can be extracted by [Bmim]- PF6 quantitatively, the acid dyes can be extracted more than 95 percent. For reactive dyes, however, the percentage removal is 64.9 percent. When the phase ratio Vo/Vaq = 1：10, ionic liquid reaches its critical saturation point. With the pH of the aqueous phase adjusted from pH 1.50 to pH 12.5, the removal efficiency of acid yellow dye RN is reduced from 99.8 percent to 13.4 percent. The higher the system temperature, the higher becomes the removal efficiency. Moreover, the addition of dicyclohexyl-18-crown-6 （CE） can enhance the removal efficiency of reactive black KN-G2RC and reactive yellow M-SR from 31.5 percent and 5.5 percent to 81.6 percent and 82.7 percent, respectively.