Activated alumina

About: Activated alumina is a research topic. Over the lifetime, 1430 publications have been published within this topic receiving 31090 citations.

Adsorption methods for treating organically coloured upland waters

Abstract: Conventional methods for treating highly coloured upland raw waters for potable water supply are relatively inefficient. Adsorption of organic colour either by activated carbon, activated alumina or bone char, particularly after preozonation of the raw water, is a possible alternative method that may be more cost‐effective. This paper summarises the properties of each adsorbent and discusses their relative performance and suitability as methods for removing organic colour from highly coloured raw waters.

Comparative study of selenite adsorption on carbon based adsorbents and activated alumina.

Abstract: The Sorption characteristics of carbon‐based adsorbents such as activated carbon and chitin for the removal of selenite, Se (IV), an anionic, hazardous contaminant, are compared with those of a and y alumina. Batch experiments were conducted to determine the influence of pH, concentration of adsorbate, adsorbent loading and temperature on the sorption characteristics of the adsorbents. Generally, low pH of the solution resulted in favorable selenium removal. With the exception of activated carbon, uptakes decreased with increase in temperature. In comparison, chitin was found to be far less effective for the removal of Se (IV) from aqueous solutions. The data also showed that y alumina provided higher selenium removal percentages (99%) compared to α alumina (94%), activated carbon (87%) and chitin (49%). The selenite removal was found to decrease with increasing initial Se (IV) concentration in the solution. Adsorption capacities of the adsorbents are reported in terms of their Langmuir adsorptio...

Optical recording medium

Abstract: PURPOSE:To greatly enhance heat resistance and light resistance of an optical recording medium at the time of projecting laser light onto the medium for reproduction and increase the number of times the medium can be used, by providing an active metallic oxide layer on a substrate to be coated, and allowing a light-absorbing material to be contained in micropores in the layer. CONSTITUTION:For an active metallic oxide layer provided on a substrate to be coated, a transparent metallic oxide such as activated alumina and activated silica is used. The transparent active metallic oxide layer is provided by, for example, applying a composition having favorable application properties, such as an alumina sol and a silica sol, to the substrate to be coated, and then drying and baking the applied material. A light-absorbing material is allowed to be contained in micropores in the metallic oxide layer. An organic coloring matter having absorptivity at the wavelength of a semiconductor laser and capable of being adsorbed on the metallic oxide layer can be used as the light- absorbing material. Particularly, naphthoquinone, anthraquinone and phthalocyanine coloring matters are effective.

A comparative adsorption for the removal of p-cresol from aqueous solution onto granular activated charcoal and granular activated alumina

Abstract: this study, the adsorption of p-cresol onto granular activated alumina (AA) was investigated in batch mode and the obtained results were compared to granular activated charcoal (AC). Experiments were carried out as a function of pH, adsorbent dosage, contact time, initial concentration, temperature and ionic strength. The experimental results indicate that, the adsorption yield increases with an increase in the adsorbent dosage. Results from the effect of pH indicate that p-cresol is preferentially adsorbed from its neutral form. Kinetics data were properly fitted with the pseudo-first-order kinetic model. The adsorption yield decreases with an increase in solution temperature. The addition of NaNO3 decreases distinctly the adsorption of p-cresol by the two adsorbents. The equilibrium uptake was increased with an increase in the initial concentration in solution. The equilibrium data fitted well to the Langmuir model with a maximum monolayer adsorption capacity of 55.80 and 56.61 mg/g, respectively for granular activated alumina and granular activated charcoal.