SILVA, M. C.; http://lattes.cnpq.br/9223059047176911; SILVA, Mirele Costa da.
Resumo:
The anisotropic ceramic membranes obtained from synthetic powders are expanding
their industrial applications, mainly because the advantages that present in terms of
permeability and resistance (chemical, thermal and mechanical). The aim of this work
is to obtain anisotropic membranes with the filtering layer of alumina synthesized by
Pechini method for applications in separation processes. Membranes were prepared
in the form of discs and later with tubular geometry with the best parameters
evaluated on disk geometry. The support has been prepared with a ceramic mass
consisted by a commercial alumina and bentonite. The intermediate layer was
obtained with kaolinite clay and the filtering layer with synthesized alumina. The
ceramic masses used for obtaining the membranes were characterized by chemical
and thermal analysis, X-ray diffraction, particle size distribution and scanning electron
microscopy (SEM). Alumina was synthesized by Pechini method in ratios of 2:1, 3:1
and 4:1 of citric acid:metallic cation. It were calcined at different temperatures and
characterized by thermal analysis, X-ray diffraction, particle size distribution, and
textural analysis by BET. Each layer that composed the membrane was
characterized by SEM and optical microscopy, by intrusion mercury porosimetry and
flow analysis with desalinated water. The intermediate and filter layer were obtained
through the deposition of dispersions by dip -coating. The results showed membranes
made with success, free from defects, with permeability of 317.53 L/h m
2
Bar. The
membranes were efficient for the application in the treatment of oily water, reducing
the concentration of 70 mg/L of oil in water at 100%; for application in separation of
indigo blue the membrane reached 100% of rejectio n of solid particles of a solution
with concentration of 0.25 g/L of indigo blue; water treatment using the raw sewage
of a river the membrane reduced color, turbidity, ions present, ammonia, silica and
iron and for application in separation of casein has been reached 97.4% of rejection
in a solution with concentration 3.08 mg/mL.