Chromium, especially the hexavalent form, is toxic to humans. Industries like chrome plating, textile, electroplating discharge Cr(VI) in their effiuents. Wastes containing chromium are environmentally persistent and toxic, and cannot be degraded or detoxified biologically. Various techniques developed for the removal of heavy metals include chemical precipitation, ion exchange and adsorption. ...

Supercritical CO2 fluid leaching (SFL) method using supercritical CO2 fluid containing a complex of HNO3 tri-n-butyl phosphate (TBP) was applied to removal of uranium from radioactive solid wastes. Sea sands, incineration ashes and porous alumina bricks were employed as matrixes of simulated solid wastes. Real radioactive incineration ash wastes and firebrick wastes were also subjected to the S...

The adsorption potential of iron acetate coated activated alumina (IACAA) for removal of arsenic [As (III)] as arsenite by batch sorption technique is described. IACAA was characterized by XRD, FTIR, EDAX and SEM instruments. Percentage adsorption on IACAA was determined as a function of pH, contact time and adsorbent dose. The study revealed that the removal of As (III) was best achieved at pH...

Loop thermosyphon is a simple and reliable device providing several times higher heat transfer than convectional coolers used in cooling electronic. The paper deals with the cooling of power electronic component by means of this device. The main object of the paper is design and construction of the device to provide heat removal from the electronic component. Paper describes function principle ...

Alumina nanofibers were prepared by a technique that combined the sol-gel and electrospinning methods. The solution to be electrospun was prepared by mixing aluminum isopropoxide (AIP) in ethanol, which was then refluxed in the presence of an acid catalyst and polyvinylpyrolidone (PVP) in ethanol. The characterization results showed that alumina nanofibers with diameters in the range of 102 to ...

The control of particle size distribution of fabricated alumina nanoparticles from general alumina that has a large geometric standard deviation (GSD) is studied. A thermophoretic separator was used to control the GSD of the fabricated alumina nanoparticles. Unevaporated particles and primary particles were separated to yield a small GSD for fabricated alumina nanoparticles. The fabricated alum...

Alumina nanorods were prepared from chromium-containing alumina sludge, and the effects of doping elements, such as Cr, Fe, and Mg, were researched. The results show that the crystal transformation of alumina is restricted by the doped Cr and facilitated by the doped Fe and Mg, which is transformed from θ-Al2O3 to α-Al2O3 in the calcination process. Meanwhile, the crystal transformation of alum...

Structured catalysts for the simultaneous removal of soot and nitrogen oxides were prepared by means of coating cordierite monoliths with alumina-based suspensions containing Cu, Co or Fe and Cs as the catalytically active phase. Textural and chemical properties of the coated monoliths were determined by means of N2-physisorption, SEM and temperature programmed reduction. Their activity in the ...

Cr(VI) is considered to be potentially carcinogenic to humans. Removal of Cr(VI) ions from aqueous solution under different conditions was investigated using activated alumina (AA) and activated charcoal (AC) as adsorbents. Batch mode experiments were conducted to study the effects of adsorbent dose, contact time, pH, temperature and initial concentration of Cr(VI). Results showed that the adso...

We compared results for the liquid-chromatographic determination of free norepinephrine and epinephrine in urine after purifying the catechols by the following methods: (a) acid-washed alumina, (b) weak cation-exchange resin (WCX), (c) a combination of weak cation-exchange resin followed by alumina (WCX-alumina), and (d) commercially available phenylboronic acid adsorbent. We evaluated analytic...