The uptake of plutonium from model solution of boric acid labelled with239Pu by natural sorbents was studied. The range of pH of solution was from 5.1 to 8. For the uptake of Pu were used different
natural and chemically modified natural sorbents of different mineralogical composition and from different deposits. The distribution
coefficients for plutonium uptake were calculated and the best conditions for uptake were evaluated.
Summary An attempt was made to obtain mineral-carbon sorbents from waste products of petrochemical industry: lime from the decarbonization of river water to be used in technology and hydrocarbon wastes obtained in the treatment of industrial waste waters. The sorbents were prepared by thermal decomposition of mixtures of the mineral and carbon components. In order to optimize the preparation conditions, physicochemical studies were performed of both the mineral matrix and the mineral-carbon sorbents. Adsorption measurements involving nitrogen, water, and benzene as adsorbates were used for determining the parameters of porous structure of the obtained materials and their hydrophilic-hydrophobic properties. The properties influencing the sorptive properties of the organic compounds present in the petrochemical wastes were pointed out.
Authors:J. Narbutt, J. Siwiński, B. Bartoś, and A. Bilewicz
Recent work directed towards synthesizing and exploring new effective sorbents for radiocesium removal from primary coolants of pressurized water nuclear reactors of the WWER type is presented. Various sorbents synthesized on the basis of titanium hexacyanoferrate are compared with one another from the point of view of their sorption efficiency and stability. The uptake of137Cs from solutions containing boric acid and millimolar quantities of ammonium and potassium ions was studied under conditions simulating the process of purification of the coolant bled from the primary circuit of the reactor. A composite-type sorbent was selected of good mechanical properties and negligible solubility, efficiently decontamining large amounts of the solution (considerably exceeding 104 bed volumes) in the course of the column process.
Authors:F. Šebesta, V. Jirásek, J. Rais, and P. Selucký
The preparation of sorbents composed of polyethylene glycol and metal(II) salts of heteropolyacids has been described. It
has been found that the calcium salt of phosphomolybdic acid of the type Ca3(PMo12O40)2 is precipitated in the presence of polyethylene glycol (m.wt. 1000). In this precipitate one calcium cation combines approximately
with 10.9 ethylene oxide units of polyethylene glycol. The solubility of the sorbents has been found to be several tenths
of a gram per litre of water or 0.1M hydrochloric acid. The sorption of radium has been studied as a function of the composition
of the sorbents. High distribution ratios (KD∼103∼104) have been reached using 0.1M hydrochloric acid solution.
The present work is an attempt to use the waste water stream, containing considerable amounts of aluminium chloride, for the
manufacture of mineral–carbon sorbents. The use of the wastewater has given a possibility of obtaining a suitable mineral
matrix of aluminium hydroxide for the sorbents. Atactic poly(propylene) (APP) have been used as the necessary carbon raw material.
The modification of aluminium hydroxide was attained by preliminary mixing with the organic component, followed by carbonisation.
Optimum conditions for obtaining Al(OH)3 have been determined and the effect of the amount of carbon matter on the properties of the materials obtained has been evaluated.
The studies have enabled to trace the changes in the structure and properties of the sorbents obtained.
Authors:M. Mallah, M. Ghannadi Maragheh, A. Badiei, and R. Habibzadeh Sbo
In the present work, results of γ-irradiation on normal and functionalized SBA-15 by aurintricarboxylic acid have been reported.
Characterization of normal and functionalized SBA-15 particles before and after γ-irradiation was carried out using Fourier-transform
infrared technique. Aurintricarboxylic acid ligand connected to SBA-15 was also analyzed using UV/Vis spectrophotometer. The
modified sorbent was then used as a new sorbent for separation of trace amounts of praseodymium and lutetium ions from nuclear
waste waters in batch techniques. Based on the results of distribution coefficients determination, and investigation of sorption
process in various conditions, the parameters were optimized for separation lanthanides. It can be concluded that the functionalized
SBA-15 is a promising sorbent for praseodymium and lutetium cations.
Authors:B. Pacewska, D. Szychowski, A. Klepańska, and P. Stefaniak
In the present work an attempt was made to obtain mineral-carbon sorbents by thermal decomposition of solid waste materials
containing, besides to mineral components, solid petroleum derivatives. The amount and the homogeneity of distribution of
coal product formed in decomposition of organic matter on the surface of the mineral matrix, as well as the porous structure
of the sorbents obtained depend largely on the conditions of calcination of the wastes used. The aim of this work was to find
optimum conditions of the process. The sorptive properties of the obtained material were checked in the process of reduction
of pollutants contained in industrial wastes.
Authors:N. Mann, T. Todd, T. Tranter, and F. Šebesta
A novel approach to preparing granular sorbents for the separation of actinides has been developed, where the extractant is directly immobilized in an inert matrix. This allows substantially higher extractant loadings in the sorbent than for conventional extraction chromatography resins. This approach utilizes polyacrylonitrile (PAN) as the inert matrix material. The well-known actinide extractant octyl (phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) has been loaded into sorbent granules at extractant loadings from 20 to 33 wt.% CMPO. The porosity of the PAN matrix allows the active material to have rapid and complete access to the solution containing the impurities, resulting in improved kinetics and higher sorption capacities. Sorbents containing CMPO were prepared using PAN as a binding matrix, and tested against commercially available actinide extraction chromatography resins. Direct comparative batch contact tests performed with TRU-ResinÒ and CMPO-PAN using an INEEL tank waste simulant, resulting in distribution coefficient (Kd) values for Am approximately 2-90 times higher for CMPO-PAN than for TRU-Resin. Batch distribution coefficient (Kd) values for Pu were approximately 60-150 times higher for CMPO-PAN than for the TRU-Resin. Acid dependency curves were generated for Am and Pu with CMPO-PAN over a concentration range of 1 mM to 5M HNO3.
Activated charcoals were analyzed by neutron activation analysis to test their applicability as sorbents for some volatile trace elements in volcanic exhalations. A high temperature volatilization process was applied, which reduces the concentrations of some trace elements, in particular Br, Hg, Sb and Zn.
In the presence of trace amounts of hydrazinium or amidosulfate ion, sufficiently high values were observed for the distribution coefficients of cesium on several insoluble ferrocyanide sorbents in a concentrated solution of nitric acid, in contrast to considerably lower values in their absence. The results indicate an inhibitory action of the above agents on the oxidation of ferrocyanide to ferricyanide with nitric acid.