Adsorption by Liquid-Liquid Extraction of Hg(II) from Aqueous Solutions Using the 2-Butyl-imidazolium Di-(2-ethylhexyl) Phosphate as Ionic Liquid

Mohamed Amine Didi, Baghdad Medjahed, Wafaâ Benaouda

Laboratory of Separation and Purification Technology, Department of Chemistry, Faculty of Sciences, Tlemcen University, Tlemcen, Algeria.

DOI: 10.4236/ajac.2013.47A006                

Abstract

In this work, a novel room temperature ionic liquid (2-butyl-imidazolium di-(2-ethylhexyl) phosphate) ([C₄mim] [D2EHPA]) was synthesized and tested as extractant in the mercury(II) liquid-liquid extraction. The effects of parameters such as aqueous to organic phase’s volume ratio, metal concentration IL concentration, pH levels, ionic strength, and temperature were reported. For the extraction of metal, [C₄mim]₃[R.HR]₃[HgCl₂]_org and [C₄mim]₃[R.HR]₃ [HgClOH]_org species were formed where (H₂R₂) was D2EHPA. In the case of ionic strength, the results showed that the addition of sodium acetate at 0.302 mmol·L^?1 to the aqueous phase strongly increased the mercury extraction yield (R = 100%). The extracted species were investigated by a calculation program using CHEAQS V. L20.1 inorder to determine the relation between the percentages of the extracted species and the extraction yield. The results showed that the extracted species in the best conditions were HgCl₂ and HgClOH with respective percentages 80.66% and 18.29%.

Keywords

Mercury; Ionic Liquid; Solvent Extraction; Speciation; Butylimidazole; Di-(2-Ethylhexyl) Phosphoric Acid

Conflicts of Interest

The authors declare no conflicts of interest.

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