Intensified reactive extraction of 4-hydroxypyridine with di(2-ethylhexyl) phosphoric acid in 1-octanol by using tributyl phosphate  

作　　者：Zhixian Chang Xiangfeng Zhou Huihua Bai Deliang Li Ling Zhang 

机构地区：[1]Henan Provincial Engineering Research Center of Green Anticorrosion Technology for Magnesium Alloys,Henan Engineering Research Center for Control and Remediation of Soil Heavy Pollution,College of Chemistry and Chemical Engineering,Henan University,Kaifeng 475004,China

出　　处：《Chinese Journal of Chemical Engineering》2023年第2期199-205,共7页中国化学工程学报（英文版）

基　　金：supported by the Science and Technology Research Project of Henan Province (192102310490 and 212102310505)。

摘　　要：The efficient separation of amphoteric organic compounds from dilute solutions is of great importance in the industrial field. In the present work, the reactive extractions of 4-hydroxypyridine(4-HP) with tributyl phosphate(TBP), di(2-ethylhexyl) phosphoric acid(D2EHPA) and TBP + D2EHPA dissolved in 1-octanol were investigated, respectively. The influences of the initial concentrations of TBP, D2EHPA and TBP + D2EHPA on distribution ratio(D) were discussed, as well as the reactive extraction mechanism were proposed. The obvious intensification effect was observed when the mixture of TBP and D2EHPA was used as extractant. The best extraction conditions were found to be of the molar ratio of D2EHPA and TBP at 2:1 and the equilibrium aqueous pH at 3.50-4.50. D values increased with the increase of the total concentration of TBP and D2EHPA in 1-octanol. Especially, the analysis on the extraction mechanisms clearly indicate(i) TBP in 1-octanol shows negligible reactive extraction toward 4-HP,(ii) D2EHPA in 1-octanol exhibits moderate extraction effect by forming 4-HP:D2EHPA(1:1) and 4-HP:2D2EHPA(1:2) type complexes, while(iii) D2EHPA in TBP/1-octanol demonstrates the maximum distribution ratio with the 4-HP:D2EHPA(1:1) type complex domination. The discussion provides new insights on the mechanism and opens a new way for the intensified extraction of amphoteric organic compounds by using the mixture of multiple extractants in the diluent.

关 键 词：4-Hydroxypyridine Di(2-ethylhexyl)phosphoric acid Tributyl phosphate Reactive extraction Intensified extraction 

分 类 号：X703[环境科学与工程—环境工程] TQ028.32[化学工程]