scholarly journals EXPERIMENTAL STUDY ON RADIOACTIVE WASTE IMMOBILIZATION IN LOW-TEMPERATURE MAGNESIUMPOTASSIUM PHOSPHATE CERAMIC MATRIX

2020 ◽  
pp. 103-113
Author(s):  
S.Yu. Sayenko ◽  
V.A. Shkuropatenko ◽  
A.V. Pylypenko ◽  
A.V. Zykova ◽  
S.A. Karsim ◽  
...  
Keyword(s):  
Salt Content ◽  
Potassium Phosphate ◽  
Radiation Stability ◽  
Activity Level ◽  
Highly Active ◽  
Radioactive Waste Immobilization ◽  
High Salt Content ◽  
Active Waste ◽  
Ceramic Compounds ◽  
Ceramic Matrices

Results of the studies carried out in NSC KIPT on application of magnesium-potassium phosphate ceramic matrices for immobilization of cesium, clinoptilolite with a cesium and solidified simulators of highly-active waste with high salt content are presented. The high radiation stability and corrosion resistance of the magnesiumpotassium phosphate ceramic matrices to leaching of radionuclide simulators, as well as basic components of solidified ceramic compounds were determined. It was shown that magnesium-potassium phosphate matrices for the solidification of liquid radioactive wastes of low and middle activity level, including waste with increased salt content, can be used in Ukrainian NPPs.

scholarly journals The Use of MgO Obtained from Serpentinite in the Synthesis of a Magnesium Potassium Phosphate Matrix for Radioactive Waste Immobilization

2020 ◽  
Vol 11 (1) ◽  
pp. 220
Author(s):  
Svetlana A. Kulikova ◽  
Sergey E. Vinokurov ◽  
Ruslan K. Khamizov ◽  
Natal’ya S. Vlasovskikh ◽  
Kseniya Y. Belova ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Hydrolytic Stability ◽  
Potassium Phosphate ◽  
Aggregate Size ◽  
Particle Morphology ◽  
Average Crystallite Size ◽  
Cost Effective ◽  
Binding Agent ◽  
Ultrasonic Dispersion ◽  
Radioactive Waste Immobilization

Magnesium oxide is a necessary binding agent for the synthesis of a magnesium potassium phosphate (MPP) matrix based on MgKPO4 × 6H2O, which is promising for the solidification of radioactive waste (RW) on an industrial scale. The performed research is devoted to finding a cost-effective approach to the synthesis of MPP matrix by using MgO with an optimal ratio of the quality of the binding agent and the cost of its production. A method for obtaining MgO from the widely available natural mineral serpentinite was proposed. The phase composition, particle morphology, and granulometric composition of MgO were studied. It was found that the obtained MgO sample, in addition to the target periclase phase, also contains impurities of brucite and hydromagnesite; however, after calcining at 1300 °C for 3 h, MgO transforms into a monophase state with a periclase structure with an average crystallite size of 62 nm. The aggregate size of the calcined MgO powder in an aqueous medium was about 55 μm (about 30 μm after ultrasonic dispersion), and the specific surface area was 5.4 m2/g. This powder was used to prepare samples of the MPP matrix, the compressive strength of which was about 6 MPa. The high hydrolytic stability of the MPP matrix was shown: the differential leaching rate of magnesium, potassium, and phosphorus from the sample on the 91st day of its contact with water does not exceed 1.6 × 10−5, 4.7 × 10−4 и 8.9 × 10−5 g/(cm2·day), respectively. Thus, it was confirmed that the obtained MPP matrix possesses the necessary quality indicators for RW immobilization.

Effect of Sodium Nitrite on Growth of Shigella flexneri

1991 ◽  
Vol 54 (6) ◽  
pp. 424-428 ◽  
Author(s):  
LAURA L. ZAIKA ◽  
ANNA H. KIM ◽  
LOUISE FORD
Keyword(s):  
Exponential Growth ◽  
Shigella Flexneri ◽  
Salt Content ◽  
Brain Heart Infusion ◽  
Growth Curves ◽  
Inhibitory Effect ◽  
Plate Count ◽  
Generation Times ◽  
High Salt Content ◽  
Lag Times

A partial factorial design study of the effect of NaNO2 (0, 100, 200, 1000 ppm) in combination with NaCl (0.5, 2.5, 4.0%), pH (7.5, 6.5, 5.5), and temperature (37, 28, 19°C) on growth of Shigella flexneri is reported. Experiments were done aerobically in brain-heart infusion medium, using an inoculum of 1 × 103 CFU/ml. Growth curves were fitted from plate count data by the Gompertz equation; exponential growth rates, lag times, generation times, and maximum populations were derived for all variable combinations. In the absence of nitrite, the organism grew well under all test conditions at 37 and 28°C but did not grow at 19°C at pH 5.5 nor at pH 7.5 with 4% NaCl. Nitrite did not affect growth in media of pH 7.5 at 37 and 28°C. At pH 6.5 growth was inhibited by 1000 ppm NaNO2. The organism failed to grow at 19°C at all nitrite levels in the presence of 2.5 or 4.0% NaCl. The inhibitory effect of nitrite was much greater in media of pH 5.5 and increased with increasing salt levels. More inhibition was apparent at 28 than at 37°C. While lack of growth was used as a paradigm of the effect of nitrite on S. flexneri, nitrite also increased the lag and generation times and decreased the exponential growth rate. Results indicated that NaNO2 in combinations with low temperature, low pH, and high salt content can effectively inhibit the growth of S. flexneri.

Resource-saving Technologies and Some Proposals for the Creation of Automated Reclamation Systems

2021 ◽  
Vol 25 (7) ◽  
pp. 8-12
Author(s):  
Z.G. Lamerdonov ◽  
T.Yu. Khashirova ◽  
S.A. Zhaboev ◽  
L.Zh. Nastueva ◽  
A.А. Shogenov ◽  
...  
Keyword(s):  
Drip Irrigation ◽  
Salt Content ◽  
Experimental Studies ◽  
Soil Surface ◽  
Growing Season ◽  
Resource Saving ◽  
Water Savings ◽  
Irrigation Method ◽  
High Salt Content ◽  
Reclamation System

The results of experimental studies of the local subsurface irrigation method in comparison with drip irrigation carried out in the laboratory, which showed water savings due to a decrease in evaporation from the soil surface by 10–15 percent are presented. The method of irrigation in closed greenhouse farms using water with a high salt content is described. The paper proposes new patented schematic solutions for protecting plants from frost and pests, describes a multifunctional engineering and reclamation system capable of performing various operations depending on the emerging problems during the growing season.

scholarly journals SUBSTANTIATION OF CHOICE OF VEGETABLE CROPS SUITABLE FOR GROWING ON SALTED SOILS

2020 ◽  
Vol 5 (4(73)) ◽  
pp. 12-18
Author(s):  
G.T. Bekmirzaev ◽  
I.A. Begmatov ◽  
D.B. Yulchiev
Keyword(s):  
Experimental Study ◽  
New Zealand ◽  
Salt Content ◽  
Vegetable Crops ◽  
Agricultural Systems ◽  
Salt Tolerant ◽  
As Species ◽  
High Salt Content ◽  
The University ◽  
Selection Of

The purpose of the experimental study was the selection of salt tolerant crops and the search for useful horticultural species for growing them on saline lands. The experimental study was conducted at the University of Algarve, Portugal, in a greenhouse. The following vegetable crops were selected for research: lettuce (Lactuca sativaL), New Zealand spinach (Tetragonia tetragonioides) and garden purslane (Portulaca oleracea). Experimental results showed that New Zealand spinach and garden purslane have high potential as species resistant to high salt content and are therefore recommended for cultivation in order to reduce soil salinity. The above crops, mainly New Zealandspinach, are good types of garden crops with high useful qualities and productivity. Therefore, it has been shown that this method is a clean and environmentally friendly tool to prevent salinization and maintain the sustainability of agricultural systems

The Effect of High Salinity Water to the Compressive Strength of Mine Backfill Material

2018 ◽  
Vol 777 ◽  
pp. 554-558
Author(s):  
Vu Hai Dang ◽  
Manoon Masniyom
Keyword(s):  
Compressive Strength ◽  
High Salinity ◽  
Saline Water ◽  
Salt Content ◽  
High Salt ◽  
Mine Backfill ◽  
High Salinity Water ◽  
Solid Ratio ◽  
High Salt Content ◽  
Salinity Water

The effect of the high salinity water on the compressive strength of mine backfill was studied. Two types of salinity water: saturated and unsaturated brines were employed to mix with mine backfill materials, and the results were compared. The one with saturated brine had high salt content of 400 g/l while the other had 200 g/l. The results showed that compressive strength decreased with increasing salt content. The mine backfill with high salt content (saturated brine) exhibited the poorest compressive strength in which its strength decreased to approximately 50-70 % of the original strength gained from the backfill samples based on water without salt. Additionally, the optimal saline water solid ratio was 0.2.

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