Phosphate Sequestration from Aqueous Solutions Using a Zeolite in the Zinc form.

This work evaluated the ability of a modified zeolite to adsorb phosphates in aqueous solution. The zeolite used for this study was a modified faujasite impregnated with zinc chloride (Z-Zn) on its surface. The experiments were carried out in different stages. Adsorption was performed at different pH of the solution and the zeolitized material was found to be favorable for phosphate adsorption. The adsorption kinetics occurred after 240 minutes and reach the equilbrium, determining chemisorption reactions with a fit of the particular diffusion model (Dp) and pseudo second order, the Langmuir model was best adjusted through the isotherms. The adsorption and desorption process occurs best in the presence of HCl, the formation of residual phosphorous in the fractionation stage evidenced that the highest percentage was bound to metals such as Fe and Al.

Phosphate Sequestration From Aqueous Solutions Using A Zeolite in The Zinc Form.

This work evaluated the ability of a modified zeolite to adsorb phosphates in aqueous solution. The zeolite used for this study was a modified faujasite impregnated with zinc chloride (Z-Zn) on its surface. The experiments were carried out in different stages. Adsorption was performed at different pH of the solution and the zeolitized material was found to be favorable for phosphate adsorption. The adsorption kinetics occurred after 240 minutes and reach the equilbrium, determining chemisorption reactions with a fit of the particular diffusion model ( Dp ) and pseudo second order, the Langmuir model was best adjusted through the isotherms. The adsorption and desorption process occurs best in the presence of HCl, the formation of residual phosphorous in the fractionation stage evidenced that the highest percentage was bound to metals such as Fe and Al.

Li in minerals from the Ilimaussaq alkaline intrusion, South Greenland

Li was analysed by instrumental neutron activation analysis and Cerenkov counting in 120 mineral samples (30 species) from the Ilfmaussaq alkaline intrusion, South Greenland. More than 0.23 wt.% Li (0.5 wt.% Li2O) is found in polylithionite, neptunite, riebeckite, Na-cookeite, ephesite, arfvedsonite, gerasimovskite and astro­phyllite. Arfvedsonite (200-2500 ppm Li) carries the bulk of Li in most of the highly alkaline rocks. Li-Mg and Li-F relations indicate that the distribution of Li is con­trolled by the structure of minerals, their absolute contents of Mg and F and the fractionation stage within the intrusion. Li is probably linked with Fin the fluid state and this linkage continues into crystallising phases where Li occupies sites which also accommodate Mg. Li/Mg and Li/F ratios of Ilfmaussaq rocks and minerals are higher than in equivalent materials from the Lovozero intrusion (Kola, Russia). The Li­Mg-Fe2+ geochemical association at Ilfmaussaq (Fe2+>>Mg) and Lovozero (Fe2+>Mg) contrasts with the commercially important Li-rich but Mg-Fe2+-poor association found in certain granite pegmatites and greisenised granites.

A Process for Enhancing Selectivity and Limiting Plugging in Plasmafractionation for Apob Removal

A new process using pressure and flow pulsations was investigated in the second stage of cascade filtration for ApoB removal. Due to enhanced filtration by the pulsations, the retentate flow vanished naturally without clamping the line, which reduced albumin and ApoA1 losses. The performance of Eval 4A and cellulose PF100 filters in this case were compared with that of classical dead end mode at a plasma flux of 18 ml/(min m2). The apparent sieving coefficient for small proteins (albumin, ApoA1) under pulsed conditions increased with increasing pressure instead of dropping as in dead end mode. In both cases the ApoB sieving coefficients remained below 0.02. These encouraging results were accompanied by a slower rise of transmembrane pressure showing a decrease of membrane plugging. Thus, the recovery of albumin and ApoA1 is increased while ApoB removal remains constant, which improves the selectivity of the fractionation stage.