β-萘酚稀溶液的络合萃取

Extraction of b -Naphthol with Tributyl Phosphate Based on Chemical Complexation

利用磷酸三丁酯(TBP)、三烷基胺(7301)为络合剂,分别采用苯、甲苯、正辛醇、煤油作为稀释剂对b-萘酚稀溶液进行络合萃取。实验结果表明,采用磷酸三丁酯-甲苯混合溶剂对b -萘酚稀溶液进行萃取,具有相当高的分配系数。同时考察了有机相中络合剂浓度、b -萘酚溶液初始浓度、溶液pH值以及温度对络合萃取相平衡分配系数的影响,建立了分配系数与稀释剂物理参数间的经验方程。

The extractant used for the complexometric extraction process to tresat the wast water containing dilute b-naphthol aqueous solution was chosed through experiments. Finally, the mixture of tributyl phosphate (TBP) and toluene was selected as the suitible extractant according to its effectiveness, Using this extractant, the distribution ratio D can reach 328 and the regeneration of extractant can be easily done by adding NaOH solution. Furthermore, the effects of the composition of the extractant, the initial concentration of b-naphthol, the pH of the aqueous phase and the extracting temperature on the extraction equilibrium had been systemetically investigated. The distribution ratio D increases with the decrease of pH and D will reach a maximum when the initial concentration of b-naphthol lies in the range of 500~800 mgL-1. The extraction process is an exothermal reaction(ΔH =-17.7 kJmol-1). When the concentration of TBP is lower than 30% (Vol.), the distribution ratio D increases with the increase of the concentration of TBP, and when the concentration of TBP is higher than 30%(Vol.), the emulsification will occur and the D will be decreased. Experimental data indicate that during extraction the b-naphthol in TBP system will form 0.5:1 tributyl phosphate b-naphthol complex. The relationship between the distribution ratio D and the physical parameters of diluents is derived.