The Adsorption and Sedimentation of Clean, Carrier-Free, Yttrium Solutions

Abstract

Zusammenfassung BesumeExperiments on the adsorption and Sedimentation of yttrium solutions have been carried out with solutions containing minimal suspended matter. It has been shown that such clean solutions of 'carrierfree' yttrium can be kept in polystyrene vessels, even at pH = 8 or more, with no Sedimentation taking place, and only a small amount of adsorption on to the vessel walls. It has also been shown that addition of 'Analar' water to such solutions converts the yttrium to a centrifugable form. It is suggested that the 'radiocoUoidal' properties of yttrium reported in the literature are due to ion exchange adsorption of yttrium ions on to suspended particulate matter and on to surfaces. Versuche über Adsorption und Sedimentation von gelöstem Yttrium wurden in Lösungen ausgeführt, die nur minimale Mengen suspendierten Materials enthalten. Es zeigte sich, daß solche reinen Lösungen "trägerfreien" Yttriums in Polystyrolgefäßen sogar bei pH 8 und mehr aufbewahrt werden können, wobei keine Sedimentation und nur wenig Adsorption an den Gefäßwänden auftritt. Bei Zusatz von "Analar"-Wasser wird das Yttrium zentrifugierbar. Wir glauben, daß die in der Literatur beschriebenen ,,radiokolloidalen" Eigenschaften des Yttriums von einer Austauschadsorption der Yttriumionen an suspendierte Partikelchen und an Oberflächen herrühren.Nous avons exp6riment6 sur l'adsorption et la Sedimentation d'yttrium dans des solutions ne contenant que des quantit^s minimales de matiere en suspension. Oes solutions pures d'yttrium sans entrameur peuvent etre conserv^es dans des r6cipients en polystyrene, meme ä pH 8 et au-dessus, sans Sedimentation et seulement une faible adsorption sur les parois. Par addition d'eau «Analar» l'yttrium prend une forme centrifugeable. Nous proposons d'expliquer les propriet^s radio-colloidales decrites dans la litterature par une absorption des ions d'yttrium par 6change sur les particules en suspension et les surfaces.

Sorption of Radionuclides by Surface Coatings

“…Samples were re-immersed for further times as required. Removal and replacement of the samples did not significantly affect the sorption isotherms, and it was found also that adsorption on the vessel-walls was always less than 1 per cent (this agrees with the observations of MELLISH et al [9]). …”

Radiological environmental impact of high‐energy accelerators

“…76 The molecular species of 7 Be formed in water surrounding the accelerator tunnel will be in the form of a strongly hydrolyzed ion, similar to the radiocolloid described by Mellish et al 78 In particular, 7 Be has been recognized as being a species which is very strongly absorbed onto surfaces from carrier-free solution; indeed, in solution in which the Be content is considerably less than the solubility product for the hydrolyzed cation, separations of carrier-free 7 Be may be made by a simple filtration. 79 -80 Therefore, it would follow that this known sorption of tracer beryllium might result in holdup in the wet rock for periods sufficient to allow significant decay to occur and to reduce concentrations in ground water due to low leach rates from the regions of greatest yields from around the accelerator ring.…”

A Radiotracer Study of Gold Adsorption on Polyethylene from Very Dilute Aqueous Solutions

“…Indeed, this double layer was proved to exist on the surface of teflon at pa values higher than 3 [20], However, it has been shown that its capacity is very small. Some authors have also pointed out the possibility of explaining adsorption phenomena by the ion exchange properties of either foreign impurities in the adsorbent or of some groups formed by a surface oxidation of polymer [3,21,22].…”

“…6 it also follows that indifferent electrolytes strongly affect the adsorption kinetics, probably due to their influence on the formation of adsorbable gold species. One might suggest that such electrolytes might either desorb the gold traces from the colloidal impurities, ever present in solution [22,23], or affect the equilibrium between various gold species due to the change in ionic strength of the solution.…”

“…It might reflect the fact that in this pa range gold is partially adsorbed in form of pseudocolloids, since the desorption of metallic gold should be independent of the pa of the desorbing solution. As known, pseudocolloids are formed due to the adsorption of trace elements on colloid impurities in solution, which are mostly of the Si0 2 type [22,23]. Since this adsorption has an ion exchange character, it depends on the pu.…”