Direct Yellow and Methylene Blue liquid-liquid extraction with alkylene carbonates.
Propylene and 1,2-butylene carbonates enable very effective extraction of Methylene Blue. The use of a more hydrophobic 1,2-butylene carbonate is preferred for practical application. Separation is enhanced by addition of an electrolyte (NaCl). Partition coefficients for solutions containing Methylene Blue and 1M NaCl are at least a hundred times higher than for Direct Yellow solutions. The recovery of Methylene Blue with propylene and 1,2-butylene carbonates is significantly better, compared with the cloud point technique. Cloud point technique yields to almost 100% only in the case of low concentrations of Methylene Blue in the feed (0.5mg dm(-3)). For higher initial concentrations (0.01-0.25 g dm(-3)) of Methylene Blue, this method of recovery provides low extraction percentages (10-40%). Alkylene carbonates are not appropriate extractants for recovery of very hydrophilic Direct Yellow.
Institute of Chemical Technology and Engineering, Poznan University of Technology, Pl. M. Sklodowskiej-Curie 2, 60-965 Poznan, Poland. magdalena.regel@put.poznan.pl
Magdalena
M
Regel-Rosocka
Jan
J
Szymanowski
D000475:Alkenes / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry / Q000302:isolation & purification*; D004396:Coloring Agents / Q000737:chemistry / Q000302:isolation & purification*; D003377:Countercurrent Distribution; D004047:Diethyl Pyrocarbonate / Q000031:analogs & derivatives / Q000737:chemistry; D008751:Methylene Blue / Q000737:chemistry / Q000302:isolation & purification*; D009281:Naphthalenes / Q000737:chemistry / Q000302:isolation & purification*; D011407:Propane / Q000031:analogs & derivatives* / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods
D000475:Alkenes; D001391:Azo Compounds; D004396:Coloring Agents; D009281:Naphthalenes; D012997:Solvents; D014874:Water Pollutants, Chemical; C502684:direct yellow; C017858:ethyl carbonate; C045990:propylene carbonate; C505760:1,2-butylene carbonate; D004047:Diethyl Pyrocarbonate; D008751:Methylene Blue; D011407:Propane