Sand granule are used as a filter bed in many ground water treatment stations to remove particulate matter from untreated water. A build up of radioactivity may take place on the granules. The disposal of those granules poses a significant problem. A batch technique was used to test the possibility of removing radioactivity from actual samples of the loaded sands. The study was limited to combined radium (226Ra and228Ra). Acidity, temperature, contact time and liquid-to-solid ratio were thoroughly investigated as factors affecting the treatment process. The data obtained are discussed on the basis of the experimental results.
Treatment of an aqueous radioactive waste solution to remove radium prior to discharge was conducted at a laboratory scale. The actual solution is mainly composed of combined radium (226Ra and228Ra) with high concentrations of manganese, iron and calcium, which are present as chlorides in dilute hydrochloric acid. Direct precipitation by sulfate anions was selected to be the more viable treatment technique. Sulfate anion concentration, free acidity, temperature and aging of the sulfate precipitate in the supernate prior to filtration are factors that were investigated for their effect on the separation efficiency. The data obtained are discussed in detail.
Authors:N. Kallithrakas-Kontos and P. Maravelaki-Kalaitzaki
Energy dispersive X-ray fluorescence (EDXRF) was employed for the identification of pigments decorating Hellenistic figurines, and the assessment of the efficiency of a treatment with barium hydroxide applied to stone. Elements present in the colored areas of the figurines, as well as the treated stone was identified by EDXRF. These data together with complementary information obtained by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction analysis (XRD) led to the identification of several precious pigments. As far as the treatment efficiency is concerned, EDXRF analysis revealed that barium is unevenly distributed on the treated surface and reaches a maximum depth of 2.5 mm.
A direct curve simulation treatment has been worked out for the evaluation of the kinetic curves of heterogeneous isotope exchange. Based on the data obtained by a personal computer some considerations have been made on the transport processes in the fully and half exchanged sodium forms of crystalline zirconium phosphate.
Authors:B. Pacewska, A. Klepańska, P. Stefaniak, and D. Szychowski
Attempt was made to evaluate the usefulness of thermoanalytical methods, combined with X-ray phase analysis and chemical analyses,
for the study of thermal decomposition of waste materials to be subjected to thermal treatment.
The object of the studies were petrochemical waste materials intended to be decomposed in a rotary furnace. Results are given
of the studies of five selected waste materials.
Authors:E. Park, H. Jo, H. Kim, K. Cho, and J. Jung
In order to reduce the toxicity of both raw wastewater and effluent from a rubber products factory, γ-ray treatment was applied
at different dose levels. The γ-ray treatment did not completely removed the toxicity, suggesting that there were major toxicants
other than destroyable organic compounds. Toxicity identification evaluation (TIE phase 1) was conducted to characterize major
toxicants using Daphnia magna. The suspected toxicants in both raw wastewater and effluent were mostly filterable materials and EDTA chelatable metals
and, to some degree, non-polar organic compounds. Anion-exchange removable compounds, most likely organics, were found only
in raw wastewater. Metal analyses showed that zinc and copper concentrations were above levels causing toxicity to D. magna. After 20 kGy γ-ray treatment of raw wastewater, filtrations both at pH 3 and at the initial pH (pH 3.6) showed dramatic
change (9 to 77% and 29 to 85%, respectively) in toxicity reduction, suggesting the formation of toxic filterable materials
which are stable even at acidic conditions. Unlike raw wastewater, there was no significant change in TIE results after γ-ray
treatment at 20 kGy for rubber effluent.
Authors:N. Lahav, D. Ovadyahu, A. Gutkin, E. Mastov, T. Menjeritzki, A. Adin, L. Rubinstein, D. Tropp, and S. Yariv
A device was constructed in which a clay suspension is hermetically heated at 220°C for a few minutes. This thermal treatment
is accompanied by a pressure increase in the cell. Once the valve is opened, there is a fast release of the pressure inside
the cell and a sudden evolution of the interparticle water. This shock leads to a quasi explosion of the clay particle. This
technique was named thermal vapour pressure shock explosion (TSE). The effect of TSE treatment on the properties of palygorskite
suspensions was investigated. Palygorskite suspensions in water are rather unstable and particles smaller than 3 μm in size
are not found before a TSE treatment. Stabilization of the suspension can be obtained by TSE treatments and/or by using a
dispersing agent such as pyrophosphate, or both. As a result of TSE treatments smaller particles are obtained, the dispersiveness
of the particles is improved and electrophoretic mobility is increased. Electron microscopy scans showed that the aggregates
of needles which form the palygorskite fibres, disintegrate to separated thin needles as a result of the TSE treatment.
Transition metal montmorillonites were saturated with benzidine (BEN) and heated gradually to 200°C, in a vacuum cell supported
by KBr windows. IR spectra were recorded before and after the thermal treatment and at various temperatures during this treatment.
X-ray diffractions were recorded before and after the thermal treatment. Hg clay shows properties similar to those of Mg and
Ca clays. In the interlayer BEN is bound to Hg through a water molecule bridge, either by proton accepting (typeA) or by proton donation (typeB). Some BEN is also protonated (typeD). Initially typeA predominates, but after the thermal treatment, when the film is rehydrated, the amounts of typesB andD increase. With Mn-, Co-, Ni-, Zn- and Cd-montmorillonite a direct coordination of the benzidine by the dehydrated metallic
cation is obtained (typeC), in addition to small amounts of typesA,B andD. During the thermal treatment water is evolved and associationsA andB are completely transformed toC. At elevated temperatures the following associations were identified in trace amounts, ammonium-amine, BEN bound to non-structured
water, hydrophobic adsorbed BEN and BEN bound to the oxygen plane (typesE, F, H andJ, respectively). During the thermal treatment of Co and Cd clays some of the benzidine was oxidized, probably to semiquinone
and quinoidal cation.
Authors:W. Wolski, E. Wolska, J. Kaczmarek, and P. Piszora
Products of hydrothermal treatment of the initial amorphous system MnxFe2−2x(OH)6−4x for 0≤x1 in 0.1x intervals, and products of their further thermal treatment, were examined by chemical analysis, X-ray, IR, and DTA techniques supported by magnetic measurements. After hydrothermal growth for lowx, hematite and goethite phases occurred. Although the goethite phase was still identifiable atx=0.6, formation of a solid solution with the isostructural groutite was not found. The ferrimagnetic spinel phase, which resists heating up to 400‡C, was present at 0.5≤x≤0.9. At higher temperatures, it transformed into the rhombohedral hematite type phase or into the cubic bixbyite phase. AtT≥900‡C, a ferrimagnetic spinel structure reappeared up tox=0.8. For x=0.9, the low- and high-temperature forms of the hausmannite phase occurred, forx= 1 passing from one form into another through Mn5O8 and partritgeite.
Authors:M. Odlyha, G. Foster, S. Hackney, and J. Townsend
The use of non-aqueous deacidification procedures as a preventive conservation measure to assist in retarding the deterioration
of painting canvases has been suggested by the Conservation Department of the Tate Gallery . The reverse sides of paintings
are treated with commercially available MMC solution (methoxy magnesium methyl carbonate). The aim of this paper is to describe
how dynamic mechanical thermal analysis can be used to evaluate the effects of this treatment. Measurements are described
on modern commercially primed canvas samples  which show that the MMC treatment does cause an increase in the modulus or
stiffness of the primed canvas materials but that the effect on theTg is minimal. The response of the treated materials to variations in relative humidity has also been studied and indications
are that the response of treated canvases to variations in relative humidity differs from those of the untreated canvases.