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Two chemical processes involving precipitation of cesium from waste solutions with iron(II)hexacyanocobaltate(III) and triphenylcyanoborate have been conducted. Various parameters have been investigated such as pH, molar ratio of Fe2+/Co(CN) 3 , molar ratio of triphenylcyanoborate to cesium and the nature of the simulated wastes. High percentage of cesium removal from different waste solutions has been achieved by using iron(II)hexacyanocobaltate(III). Precipitation of cesium with triphenylcyanoborate depends mainly on the concentration of triphenylcyanoborate and cesium as well as the molar ratio in solution. Triphenylcyanoborate can be used as a selective precipitant for cesium in both acidic and alkaline solution ofpH not more than 10.

Cesium, coprecipitated with copper ferrocyanide, can be readily removed from radioactive process waste water using sodium lauryl sulphate (NaLS), cetyl trimethyl ammonium bromide (CTAB) or gelatin (Gl) as collector. In addition to the effect of the collector type on the percentage removal and volume reduction, the effects of the pH of three distinct Cu 2 + : Fe(CN)J ~ ratios and of different ageing periods of the cesium-copper ferrocyanide-water systems have been established. With NaLS, CTAB and Gl successful removals could be achieved in the pH ranges 3-7.5, 5.0-10.5 and 5.5-9.0 respectively. The results are discussed in terms of the ionization of the active groups of the collectors and of the electrical state of the precipitate.

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KAMAL SHAKIR, KAMAL BENYAMIN, and MOURAD AZIZ. Can. J. Chem. 62, 51 (1984). Foam separation investigations over the 2.5-10.5 pH range show that U(V1) can be successfully separated from aqueous solutions by precipitation with oxine and subsequent flotation of the precipitate, either in absence or in presence of surfactant collectors. Collectors tested were: cetyl trimethyl ammonium bromide (CTAB) and sodium lauryl sulphate (NaLS). The extent of removal depends on many factors and removals as high as 98% could be achieved when uranyl oxinate precipitate was floated, under certain controlled conditions, in the presence of CTAB. Factors affecting the percentage removal were investigated and the best conditions were selected. The results obtained are discussed in terms of the hydrolytic behaviour of U(V1).KAMAL SHAKIR, KAMAL BENYAMIN et MOURAD AZIZ. Can. J . Chem. 62, 51 (1984). Des etudes sur la skparation des mousses dans l'intervalle de pH allant de 2,5 h 10,5 revdent que le U(V1) peut Stre sCpark avec succ&s des solutions aqueuses par prtcipitation avec l'oxine et une flottation subskquente du precipite en presence ou non de collecteurs surfactants. Les collecteurs CtudiCs sont: le bromure de ~CtyltrimCthylammonium (BCTA) et le sel de sodium du sulfate de lauryle (NaLS). Le taux de skparation dCpend de plusieurs facteurs et on peut rCaliser une sCparation i 98% lorsqu'on fait flotter le prCcipitt d'oxinate d'uranyle dans certaines conditions contrblkes en presence de BCTA. On a CtudiC les facteurs qui influencent le pourcentage de sCparation et on a choisi les meilleurs conditions. On discute des rksultats obtenus en fonction du comportement hydrolytique de l'U(V1).[Traduit par le journal]