Adsorber resin

Gaseous and particulate pollutants are withdrawn isoldnetically from an emission source and collected in a multicomponent sampling train. Principal components of the train include a high-efficiency glass- or quartz-fiber filter and a packed bed of porous polymeric adsorbent resin (typically XAD-2 or polyurethane foam for PCBs). The filter is used to collect organic-laden particulate materials and the porous polymeric resin to adsorb semivolatile organic species (com-... 

Three external MSA s are considered for removing ammonia from water, air (Si), activated carbon (S2) and an adsorbing resin (S3). The data for the candidate MSA s are given in Table 4.1. The equilibrium data for the transfer of the pollutant from the waste stream to the jth MSA is given by. 

Suspension Model of Interaction of Asphaltene and Oil This model is based upon the concept that asphaltenes exist as particles suspended in oil. Their suspension is assisted by resins (heavy and mostly aromatic molecules) adsorbed to the surface of asphaltenes and keeping them afloat because of the repulsive forces between resin molecules in the solution and the adsorbed resins on the asphaltene surface (see Figure 4). Stability of such a suspension is considered to be a function of the concentration of resins in solution, the fraction of asphaltene surface sites occupied by resin molecules, and the equilibrium conditions between the resins in solution and on the asphaltene surface. Utilization of this model requires the following (12) 1. Resin chemical potential calculation based on the statistical mechanical theory of polymer solutions. 2. Studies regarding resin adsorption on asphaltene particle surface and... 

Figure 4. Asphaltene particle peptization effected by adsorbed resin molecules. This physical model is the basis of our asphaltene Thermodynamic-Colloidal Model.

Vicenzi, J.T., Zmijewski, M.J., Reinhard, M.R. et al. (1997) Large-scale stereoselective enzymatic ketone reduction with in-situ product removal via polymeric adsorbent resins. Enzyme and Microbial Technology, 20, 494-499. 

The urine of people who are heavy smokers contains mutagenic chemicals, chemicals that cause mutations in biological cells. Bioanalytical laboratories can analyze urine samples for these chemicals, but the samples must be cleaned up first prior to extraction with methylene chloride. The procedure for this cleanup utilizes an open column chromatography. Columns several inches tall and about an inch wide are prepared by packing them with an adsorbing resin that has been treated with methyl alcohol. The urine samples are passed through these columns as part of the sample preparation scheme. 

XAD-16 adsorber resin (16 g) (Rohm and Haas France S.A.S., Lauterbourg, France) isopropanol (2 L) ethyl acetate (4.4 L) saturated NaCl solution (800 mL)... 

The purification of bacterial constituents usually starts in a very conventional way with an extraction step of the crude broth at neutral or slightly acidic pH. Mycelium-forming organisms are separated by filtration, and the cell mass and the filtrate are extracted separately. For the liquid phase, adsorber resins allow high recovery rates of metabolites and low process costs due to repeated use of the resins. If liquid-liquid extraction has to be applied, medium or highly polar solvents are favored. Ethyl acetate is the solvent of choice, and only in few cases is butanol superior. To extract the moist cell material, ethyl acetate, acetone or dichloromethane/methanol can be used. 

Rohm and Flaas Company has developed Amberlite polymeric adsorbent resins that can be used to remove organic compounds from contaminated groundwater, aqueous wastes, and vapor-phase wastes. Amberlite XAD-4 is a crosslinked polystyrene-type polymer. It is hydrophobic and has no ionic functional groups incorporated into its resin structure. The material is most useful in removing low-molecular-weight organic substances from aqueous systems. Amberlite XAD-4 has been commercially available since the 1970s. 

Haemodialysis and haemoperfusion which is a passage of blood through a charcoal or adsorbent resin column may be instituted, depending upon the patient s condition. 

Nollensteyn (1924) originally proposed that asphaltenes present in a hydrocarbon medium associated into micelles, with adsorbed resins acting... 

Sample pretreatment is necessary if the sample contains color and various organic compounds. To remove such interference, pass the sample through a purified, solvent-washed adsorbent resin bed. 

To 100 mL sample or pretreated sample eluant eluted through the adsorbent resin, add a few drops of HN03 to bring down the pH to 2. Add 5 mL ferric nitrate solution and mix. Fill a 5 cm cell and measure absorbance against a reagent blank at 460 nm. 

Immobilization. We have worked with different carriers for immobilization. Active immobilized preparations have been obtained by adsorption on macroporous, weakly basic anion exchange resins, and on nonionic adsorbent resins. Resins of both acrylic and phenol-formaldehyde have been used (8). In the following examples we have used lipase immobilized on nonionic adsorbent acrylic resin. 

Lipases A and B have been immobilized on nonionic adsorbent resins. Comparisons have been carried out with a similar immobilization of the crude C. antarctica enzyme. 

Water softeners in action (Experiment 126) Sequestering a detergent by adsorbing resins (Experiment 128)... 

Separation of a dye stuff from effluent water by means of adsorbing resins (Experiment 111)... 

Determining the molecular weights of asphaltenes is a problem because they have a low solubility in the liquids often used for determination. Also, adsorbed resins lead to discrepancies in molecular-weight determination, and precipitated asphaltenes should be reprecipitated several times prior to the determination (12). Thus, careful precipitation and careful choice of the determination method are both very important for obtaining meaningful results. 

Polymeric adsorption resins — A series of polymeric adsorbents has recently been developed that can adsorb hydrocarbons from aqueous systems. They derive their adsorptive properties from a combination of macroreticular porosity, pore size distribution, high surface area, and the aliphatic nature of their structure. Adsorbent resins can produce water containing less than 1 ppm oil. 

Solvent or no solvent. For tar sampling from updraft gasifier producer gases, a solvent is needed because direct condensation of the tars without diluting media can result in further reactions (polymerisation). The reactivity is suppressed by using a diluent like an absorbing liquid or an adsorbent resin. 

Treatment of Fruit Juices with Adsorber Resins... 

Adsorber resin treatment can remove certain undesired substances from juices and can be used to improve colour and taste. 

The type of resin has to be specifically determined for the desired application. These adsorber resins must not mistakenly be compared with ion exchange resins. Adsorber resins only adsorb certain molecules but otherwise do not have ion exchange properties. The working principle is similar to that of active charcoal. 

Early (not quite mature) citrus juices, lemon, Hamlin and Navel juices can develop the so-called limonin-bittemess. Additionally, there can also be a flavonoid-induced bitterness, like naringin in grapefruit juice. Adsorber resin treatment can successfully eliminate this bitterness below the detectable limit. See also [20]. 

Polystyrene-divinylbenzene cross-linked copolymer adsorbent resins removed effectively both limonin and naringin from citrus juices (44). Over 85% of limonin was adsorbed from about 50 bed volume juices of grapefruit, navel orange, lemon and tangerine. Up to 70% of naringin was also removed from grapefruit juice. 

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