000000850 001__ 850
000000850 035__ $$a21965 
000000850 037__ $$aROMDOC-THESIS-2016-338
000000850 041__ $$arum
000000850 100__ $$aAlexandrescu, Lygia Ulpiana
000000850 245__ $$aContribuţii la recuperarea vanadiului din reziduurile petroliere utilizând sol-gel modificat cu liganzi 
000000850 260__ $$c2008-05-24
000000850 520__ $$aABSTRACT The main objective of this study was to assess the technical feasibility of the recovery of vanadium from petroleum boiler ash using a new method. Recovery of vanadium from ash resulting from petroleum coke combustion was studied in a two-step method involving: • a hydrometallurgical ash treatment and • a chelation step with sol gel modified ligands. Sol gels containing iminodiacetic acid, ethylenediaminetetracetic acid, imidazole and polyethylenimine as ligands were prepared and used for the adsorption-desorption studies. The ability of these ligands to bind vanadium complexes was investigated both in batch and column procedures, using atomic absorption spectroscopy for vanadium analysis. The sorption of vanadium on these modified silica gels was studied as a function of the: • pH, • concentration of vanadium ions, • ionic strength of the aqueous solution and the kinetics of vanadium removal process were also investigated. The adsorption was found to follow the Langmuir adsorption isotherm. Sol gel adsorption capacities with respect to vanadium were found to vary from 3.8 mg V / g sol gel (for iminodiacetic acid) to 6.5 mg V / g sol gel (for imidazole). A quantitative desorption varying from 82 to 100% was achieved from the vanadium loaded solgels and reuse of the gel was possible. The mass transfer coefficients computed from the column experiment data are ranging between 1.8 and 2.4 x 10-5 m/s and strongly depend on the fluid flow rates
000000850 6531_ $$aVanadiu -- Recuperare -- Deşeuri petroliere -- Teză de doctorat
000000850 6531_ $$aDeşeuri petroliere -- Tratare -- Teză de doctorat
000000850 6531_ $$aHidrometalurgie -- Teză de doctorat
000000850 8560_ $$ff_costache@library.pub.ro
000000850 8564_ $$uhttp://romdoc.upb.ro/record/850/files/$$zAccess to Fulltext
000000850 980__ $$aTHESIS