D2EHPA萃取回收Cr_的研究.pdfVIP

21 5 No.5 Vol.21 2007 10 Journal of Chemical Engineering of Chinese Universities Oct. 2007 1003-9015(2007)05-0849-04 D2EHPA Cr() , , ( , 100084) Cr()2-(D2EHPA)Cr() pH Cr()D2EHPA pH D2EHPA/Cr() pH 2 D2EHPA Cr()pH D2EHPA Cr() pH D2EHPA NaOH 10%~20%D2EHPA// Cr() 90 D2EHPA pH X788 A Recovery of Chromium() by Solvent Extraction with D2EHPA HUO Xiao-ping, QIN Wei, SUN Xiao-wei, DAI You-yuan (State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China) Abstract: In order to recover Cr(III) from wastewater, the behavior of Cr(III) extraction with di-02-ethylhexyl phosphoric acid (D2EHPA) as extractant and kerosene as solvent was studied. The effects of species of saponifier, pH of the aqueous solution, varieties of extractant modifier and D2EHPA concentration on the extraction equilibrium were investigated. It was found that when D2EHPA/kerosene are used, the extraction of Cr(III) is predominated by the pH of the solution, and the Cr(III) can hardly be extracted with D2EHPA when pH2, while a high efficiency can be achieved by using saponifier to increase the pH of the aqueous solution. Using NaOH as saponifier will have a better phase separation than that of using NH4OH. It was also found that the extraction efficiency increases with the increase of modifier concentration used, and using modifier 1-octanol with concentration of 10%~20% is appropriate. Furthermore, the efficiencies of reverse extraction of Cr(III) loaded D2EHPA with using three kinds of inorganic acids and two kinds