Phosphate, sulfate adsorption

Feldspar, among many natural substances such as termite mount-clay, saw dust, kaolinite, and dolomite, offers significant removal ability for phosphate, sulfate, and color colloids. Optimization laboratory tests of parameters such as solution pH and flow rate, resulted in a maximum efficiency for removal of phosphate (42%), sulfate (52%), and color colloids (73%), x-ray diffraction, adsorption isotherms test, and recovery studies suggest that the removal process of anions occurs via ion exchange in conjunction with surface adsorption. Furthermore, reaction rate studies indicated that the removal of these pollutants by feldspar follows first-order kinetics. Percent removal efficiencies, even under optimized conditions, will be expected to be somewhat less for industrial effluents in actual operations due to the effects of interfering substances [58]. 

Parfitt, R.L. Smart, R.S.C. (1977) Infrared spectra from binuclear bridging complexes of sulphate adsorbed on goethite (a-FeOOH). J. Chem. Soc. Faraday Trans. I. 73 796-802 Parfitt, R.L. Smart, R.S.C. (1978) The mechanism of sulfate adsorption on iron oxides. Soil Sci. Soc. Am. J. 42 48-50 Parfitt, R.L. (1980) Chemical properties of variable charge soils. In Theng, B.K. (ed.) Soils with variable charge. N. Z. Soc. Soil Sci., Lower Hutt. N. Z., 167-194 Parfitt, R.L. (1982) Competitive adsorption of phosphate and sulphate on goethite (a-FeOOH) A note. New Zealand J. Sci. 25 147-148... 

The commonly recognized adjuvants are remarkable for their diversities. Soluble immunogens can be adsorbed onto the following kinds of inorganic suspensions alumina cream, aluminum phosphate, and aluminum sulfate. Adsorption onto organic carriers such as blood, charcoal, calcium alginate, or polyacrylamide gels has also enhanced responses. A Maalox... 

A much purer preparation of acid phosphatase from horse erythrocytes was obtained by Ito et al. (12) by adding the DEAE-chromatography procedure to the method of Tsuboi and Hudson (T2). Since this procedure may be applicable to human erythrocytes, it will be mentioned briefly. One liter of horse erythrocytes was washed and lysed by the addition of 4 liters of distilled water. One liter of calcium phosphate gel suspension was added to the hemolysate to remove most of the nonenzymatic protein, and the mixture was centrifuged. Five liters of the gel suspension were added to the supernatant, resulting in the adsorption of the enzyme. The enzyme was eluted with citrate-acetate buffer, pH 4.5, and solid ammonium sulfate was added to the eluate up to 60% saturation. The precipitate was collected, dissolved in 40 ml of water, dialyzed against water at 5°C for 10 hours, and again subjected to calcium phosphate gel adsorption, elution, and precipitation with solid ammonium sulfate to 60% saturation. 

Geelhoed, J.S., Hiemstra. T, and van Riemsdijk, W.H., Phosphate and sulfate adsorption on goethite Single anion and competitive adsorption, Geochim. Cosmochim. Acta, 61, 2389, 1997. 

It has long been evident that the separation of serum protein components effected by Howe s method is exceedingly crude due to overlapping of precipitation limits of individual proteins, incomplete precipitation at the specified concentrations of sodium sulfate, adsorption of proteins in solution upon protein precipitates, and other causes. Butler and associates (37, 38), Majoor (229), and others have not been able to confirm the precipitation breaks in the solubility curves at the sodium sulfate concentrations indicated by Howe, either directly by precipitation of normal human serum or plasma with increasing concentrations of sodium sulfate, or by comparison with solubility curves obtained with potassium phosphate. Moreover, electrophoretic analysis... 

Graded Adsorbents and Solvents. Materials used in columns for adsorption chromatography are grouped in Table 12 in an approximate order of effectiveness. Other adsorbents sometimes used include barium carbonate, calcium sulfate, calcium phosphate, charcoal (usually mixed with Kieselguhr or other form of diatomaceous earth, for example, the filter aid Celite) and cellulose. The alumina can be prepared in several grades of activity (see below). 

Biosorption is a rather complex process affected by several factors that include different binding mechanisms (Figure 10.4). Most of the functional groups responsible for metal binding are found in cell walls and include carboxyl, hydroxyl, sulfate, sulfhydryl, phosphate, amino, amide, imine, and imidazol moieties.4 90 The cell wall of plant biomass has proteins, lipids, carbohydrate polymers (cellulose, xylane, mannan, etc.), and inorganic ions of Ca(II), Mg(II), and so on. The carboxylic and phosphate groups in the cell wall are the main acidic functional groups that affect directly the adsorption capacity of the biomass.101... 

Haywood and Riley [14] have described a spectrophotometric method for the determination of arsenic in seawater. Adsorption colloid flotation has been employed to separate phosphate and arsenate from seawater [15]. These two anions, in 500 ml filtered seawater, are brought to the surface in less than 5 min, by use of ferric hydroxide (added as 0.1 M FeC 2 ml) as collector, at pH 4, in the presence of sodium dodecyl sulfate [added as 0.05% ethanolic solution (4 ml)] and a stream of nitrogen (15 ml/minutes). The foam is then removed and phosphate and arsenate are determined spectrophotometrically [16]. Recoveries of arsenate and arsenite exceeding 90% were obtained by this procedure. 

Yoshimura et al. [193] carried out microdeterminations of phosphate by gel-phase colorimetry with molybdenum blue. In this method phosphate reacted with molybdate in acidic conditions to produce 12-phosphomolybdate. The blue species of phosphomolybdate were reduced by ascorbic acid in the presence of antimonyl ions and adsorbed on to Sephadex G-25 gel beads. Attenuation at 836 and 416 nm (adsorption maximum and minimum wavelengths) was measured, and the difference was used to determine trace levels of phosphate. The effect of nitrate, sulfate, silicic acid, arsenate, aluminium, titanium, iron, manganese, copper, and humic acid on the determination were examined. 

The application of the activity of the surfactant has been examined also for the surface tension and adsorption of disodlum alkyl phosphate(6,7), sodium dodecyl sulfate(37), alkyl trimethylammonium bromide(35 ), and sodium perfluorooctanoate(13) solutions. These studies show that the surface tension and theadsorption amount are controlled by the activity of surfactant, irrespective of the added electrolyte concentration. 

Anion adsorption by goethite and gibbsite. II. Desorption of anions from hydrous oxide surfaces. J. Soil Sci. 25 16-26 Hiradate, S. Inoue, K. (1998) Interaction of mugineic acid with iron (hydr)oxides Sulfate and phosphate influences. Soil Sci. Soc. 

Competitive adsorption of sulfate and oxalate on goethite in the absence or presence of phosphate. Soil Sci. 164 180-189... 

For anionic monolayers, the reversal of the tt-A isotherms can be explained in terms of a competition between the anionic head groups and the alkali metal cations for molecules of water. If a modified Stern-type model of the plane interface is assumed, this interface will be composed of distinct adsorption sites, with counterions (cations) of finite size that can adsorb on these sites if the standard free energies of adsorption are favorable. If the anionic head group is more polarizable than water, as with carboxylic acids or phosphates, the hydration shell of the cation is incompletely filled, and the order of cation sizes near the interface is K+ > Na+ > Li+. When the polarizability of the anionic group is less than that of water, as with the sulfates, the lithium cation becomes the most hydrated one, and the order of cation sizes becomes Li+ > Na+ > K+. 

Selective adsorption on glass Ammonium sulfate fractionation Ammonium sulfate fractionation Ethanol precipitation Sonic disintegration Selective adsorption on cellulose phosphate CM-cellulose chromatography Acetone precipitation Ammonium sulfate fractionation Ethanol precipitation Selective adsorption on cellulose phosphate Ammonium sulfate fractionation Lysozyme and trypsin digestion Ammonium sulfate fractionation DEAE-cellulose chromatography Ammonium sulfate fractionation... 

A strong adsorption of dyes observed in IC columns was not encountered in CE when analyzing chloride, sulfate and phosphate in sulfonated dyes [52]. Proteins need not be removed prior to CE analysis and do not interfere with low-molecular-mass ions as is the case in IC [53]. 

Manganese oxides As(lll) and As(V) removal by Mn02(s) is similar, up to 5 mmol As mol-1 Mn at micromolar As equilibrium solution concentrations. Freundlich isotherm obeyed. As(lll) oxidized to As(V). Rapid oxidation (minutes) and adsorption of As(lll). Monitored Mn release and effect of pH, Ca, phosphate, and sulfate Driehaus, Seith and Jekel (1995)... 

Haussmann, D.D. and Anderson, M.A., 1985. Using electrophoresis in modelling sulfate, salinity and phosphate adsorption on to goethite. Environmental Science and Technology, 19 544-551. 

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