Experimental Studies Concerning the Semipermeable Membrane Separation Efficiency for 134Cs, 137Cs, 57Co, 58Co, 60Co, 54Mn in Liquid Radioactive Waste I. Treatment of secondary waste from POD decontamination procedure

2008 ◽  
Vol 59 (5) ◽  
Author(s):  
Mirela Dulama ◽  
Nicoleta Deneanu ◽  
Cristian Dulama ◽  
Margarit Pavelescu
Keyword(s):  
Membrane Separation ◽  
Separation Efficiency ◽  
Liquid Radioactive Waste ◽  
Experimental Studies ◽  
Experimental Tests ◽  
Suspended Solid ◽  
Process Efficiency ◽  
Active Charcoal ◽  
Precipitation Process ◽  
Pre Treatment

The paper presents the experimental tests concerning the treatment by membrane techniques of radioactive aqueous waste. Solutions, which have been treated by using the bench-scale installation, were radioactive simulated secondary wastes from the decontamination process with modified POD. Generally, an increasing of the retention is observed for most of the contaminants in the reverse osmosis experiments with pre-treatment steps. The main reason for taking a chemical treatment approach was to selectively remove soluble contaminants from the waste. In the optimization part of the precipitation step, several precipitation processes were compared. Based on this comparison, mixed [Fe(CN)6]4-/Al3+/Fe2+ was selected as a precipitation process applicable for precipitation of radionuclides and flocculation of suspended solid. Increased efficiencies for cesium radionuclides removal were obtained in natural zeolite adsorption pre-treatment stages and this was due to the fact that volcanic tuff used has a special affinity for this element. Usually, the addition of powdered active charcoal serves as an advanced purifying method used to remove organic compounds and residual radionuclides; thus by analyzing the experimental data (for POD wastes) one can observe a decreasing of about 50% for cobalt isotopes subsequently to the active charcoal adsorption.. The semipermeable membranes were used, which were prepared by the researchers from the Research Center for Macromolecular Materials and Membranes, Bucharest. The process efficiency was monitored by gamma spectrometry.

scholarly journals Theoretical and Experimental Studies of Uneven Dust Suction from a Multi-Cyclone Settling Tank in a Two-Stage Air Filter

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8396
Author(s):  
Tadeusz Dziubak
Keyword(s):  
Internal Structure ◽  
Separation Efficiency ◽  
Settling Tank ◽  
Experimental Studies ◽  
Experimental Tests ◽  
Air Filter ◽  
Pressure Drops ◽  
Dust Trap ◽  
Air Stream ◽  
Before And After

In this paper, the uneven air stream distribution problem of individual cyclones is studied in the multi-cyclones of intake air filters in special vehicles’ engines. This problem increases in multi-cyclones, in which several dozen cyclones have a common dust trap from which the collected dust is continuously removed by ejection suction. The aim of this study is the recognition of the theoretical and experimental possibility of reducing the streams’ unevenness, which should result in an efficiency increase in multi-cyclone separation. The methods that led to obtaining a relative stream uniformity from the suction of individual cyclones was analyzed. The method for creating equal pressure drops between the suction streams in the channels was used to achieve this goal. For this purpose, the internal structure of the multi-cyclone settler was changed. The multi-cyclone settling tank space was divided by vertical partitions into independent segments. The settling tank segment was then divided with horizontal shelves into suction channels of different heights, which were assigned a specific number of individual cyclones. The suction channels’ height was theoretically selected in terms of the equal resistance to air stream flow through the channels. For this purpose, the multi-cyclone dust settler segment model was developed. The theoretically determined suction channel’s height was verified by performing experimental flow tests in four (A, B, C, D) dust settler variants. Suction streams of satisfactory uniformity from the cyclones of the variant D settling tank were obtained at a level of 5%. In the next stage, experimental tests of the segment cyclones were carried out with dust before and after the division into suction channels of variant D for the settling tank. A significant increase was achieved from 93.73% to 96.08% in the cyclones’ separation efficiency, which were located as far away from the suction stub as possible and led to a reduction in the non-uniformity of cyclone efficiency in the segment. It follows that the multi-cyclone dust settling segment’s internal structure change gave the expected results.

Efficiency of X-ray radiometric separation in preliminary concentration of ore

2020 ◽  
pp. 431-442
Author(s):  
E. F. Tsypin ◽  
T. Yu. Ovchinnikova ◽  
T. A. Efremova
Keyword(s):  
Separation Efficiency ◽  
Physical And Mechanical Properties ◽  
Size Composition ◽  
Raw Material ◽  
Process Efficiency ◽  
Separation Plant ◽  
Processing Technologies ◽  
X Ray ◽  
Degree Of Dissociation ◽  
Pre Treatment

One of the efficient approaches to improvement of mineral processing technologies is the enhancement of ore pre-treatment with preliminary concentration. A promising dressing technique is X-ray fluorescent separation applied to various minerals to date. This process efficiency depends on various factors connected with characteristics of minerals to be processed, dressability of minerals in the preliminary concentration, geological characteristics, physical and mechanical properties of minerals, specifics of the pre-treatment circuits and modes, as well as with features of X-ray fluorescent separation. The research is aimed to study the influence of the factors which govern expediency and application condition of X-ray fluorescent separation for the preliminary concentration of mineral raw materials. The research methods were modeling of hypothetical ore grading with respect to the content of ore components with plotting of limit curves of separation, testing on X-ray fluorescent separator SRF-100L, theoretical analysis of formulas for calculating ultimate dressability indices as well as analytical calculations of particle size distribution and quality of complex ore separation by the ore separation plant circuit. The research has found that efficiency of the preliminary concentration grows with the lower content of useful component in raw material and with higher degree of dissociation of this component. Efficiency of using ore separation plant circuit in the preliminary concentration depends on the ore hardness and on drilling-and-blasting design, as well as on the circuit and modes of crushing and screening at the ore separation plant, including the number of the machine sorting classes accepted in the circuit. The preliminary concentration technologies with X-ray fluorescent separation should be developed with regard to the influence exerted on the ore separation efficiency by the material constitution of ore and dissociation of mineral phases to sizes suitable for the preliminary concentration, grain size composition of the material before separation, which depends on the parameters of mining, drilling-and-blasting and pre-treatment with crushing and screening, as well as on the ore separation plant circuit and machine sorting classes. The research results are applicable to development of the preliminary ore concentration technologies with X-ray fluorescent separation

scholarly journals Дослідження впливу ультразвукової обробки води на проростання насіння цукрового буряку

2013 ◽  
pp. 30-31
Author(s):  
О. В. Ківа ◽  
В. В. Грибініченко
Keyword(s):  
Comparative Analysis ◽  
Seed Germination ◽  
Sugar Beet ◽  
Water Supply ◽  
Ultrasonic Treatment ◽  
Experimental Studies ◽  
Experimental Tests ◽  
Plain Water ◽  
Municipal Water Supply ◽  
Pre Treatment

Були проведені експериментальні дослідження для визначення впливу попередньої ультразвукової обробки води на схожість та енерґію проростання насіння цук-рового буряка. Крім того проводились експеримента-льні дослідження із вивчення впливу тривалості уль-тразвукової обробки на енерґію проростання. Пода-ються результати проведених експериментальних випробувань та одержані характеристики процесу проростання насіння в звичайній воді з міського водо-гону та у воді, яку попередньо піддавали ультразву-ковій обробці, проводиться їх порівняльний аналіз. Experimental studies have been conducted to determine the effect of ultrasonic pre-treatment of water on germination and vigor of seeds of sugar beet. Experimental studies have been conducted to determine the effect of duration of ultrasonic treatment on vigor. Served results of experimental tests and obtained characteristics of the process of seed germination of plain water from the municipal water supply and water that previously was subjected to ultrasonic treatment and a comparative analysis are conducted.

scholarly journals Purification of Dairy Wastewaters by Advanced Oxidation Processes and Membrane Filtration

2017 ◽  
Vol 11 (1) ◽  
pp. 32-38
Author(s):  
Mihály Zakar ◽  
Erika Lakatos ◽  
Gábor Keszthelyi-Szabó ◽  
Zsuzsanna László
Keyword(s):  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Separation ◽  
Separation Efficiency ◽  
Scale Up ◽  
Separation Processes ◽  
Physicochemical Changes ◽  
Current Trends ◽  
Pre Treatment ◽  
Cost Efficient

Membrane separation processes are space and cost-efficient, easy to scale-up operations, which have proved to treat food industrial wastewaters efficiently. Beside the advantages like high separation efficiency without any chemical changes and low energy-intensity, membrane filtration also has drawbacks, like decreased operational efficiency caused by flux decile resulting from fouling and concentration polarization. Combination of oxidation pre-treatment and membrane filtration is a promising method for decreasing fouling due to the physicochemical changes caused by pre-oxidation of the wastewater in structure of colloidal pollutants and in the interactions between the foulants and the membrane material. The aim of this work is to identify the parameters affecting the membrane fouling during treatment of dairy wastewaters, and present the current trends of research in this field.

Influence of the Addition of Inorganic Salt in Obtaining Hybrid Membranes

2016 ◽  
Vol 869 ◽  
pp. 803-808 ◽  
Author(s):  
Keila Machado Medeiros ◽  
Diego Farias Lima ◽  
Carlos Antônio Pereira de Lima ◽  
Edcleide Maria Araújo ◽  
Hélio Lucena Lira ◽  
...  
Keyword(s):  
Inorganic Salt ◽  
Membrane Separation ◽  
Separation Efficiency ◽  
Bentonite Clay ◽  
Precipitation Process ◽  
Hybrid Membranes ◽  
X Ray Diffraction ◽  
Separation Processes ◽  
X Ray ◽  
Phase Inversion Technique

The membrane separation processes have low power consumption, higher separation efficiency, simplicity of operation and high quality end product. In this work, hybrid membranes of polyamide6 with bentonite clay were obtained by adding an inorganic salt. The hybrids were obtained by the melt intercalation method. The membranes were prepared by phase inversion technique by varying the percentage of inorganic salt and the time of exposure of the membranes during the immersion-precipitation process. The hybrid and hybrid membranes with and without the addition of the inorganic salt were characterized by X-ray diffraction (XRD). The results from XRD showed that the hybrid and hybrid membranes with and without inorganic salt presented an exfoliated and/or partially exfoliated structure. The addition of the inorganic salt did not cause significant changes with respect to the crystalline behavior of the polymer under study.

Separation of Biologically Active Compounds by Membrane Operations

2017 ◽  
Vol 23 (2) ◽  
pp. 218-230 ◽  
Author(s):  
Xiaoying Zhu ◽  
Renbi Bai
Keyword(s):  
Energy Consumption ◽  
Bioactive Compounds ◽  
Membrane Fouling ◽  
Membrane Separation ◽  
Separation Efficiency ◽  
High Energy ◽  
Separation Processes ◽  
Membrane Processes ◽  
Separation Technology ◽  
Pressure Driven

Background: Bioactive compounds from various natural sources have been attracting more and more attention, owing to their broad diversity of functionalities and availabilities. However, many of the bioactive compounds often exist at an extremely low concentration in a mixture so that massive harvesting is needed to obtain sufficient amounts for their practical usage. Thus, effective fractionation or separation technologies are essential for the screening and production of the bioactive compound products. The applicatons of conventional processes such as extraction, distillation and lyophilisation, etc. may be tedious, have high energy consumption or cause denature or degradation of the bioactive compounds. Membrane separation processes operate at ambient temperature, without the need for heating and therefore with less energy consumption. The “cold” separation technology also prevents the possible degradation of the bioactive compounds. The separation process is mainly physical and both fractions (permeate and retentate) of the membrane processes may be recovered. Thus, using membrane separation technology is a promising approach to concentrate and separate bioactive compounds. Methods: A comprehensive survey of membrane operations used for the separation of bioactive compounds is conducted. The available and established membrane separation processes are introduced and reviewed. Results: The most frequently used membrane processes are the pressure driven ones, including microfiltration (MF), ultrafiltration (UF) and nanofiltration (NF). They are applied either individually as a single sieve or in combination as an integrated membrane array to meet the different requirements in the separation of bioactive compounds. Other new membrane processes with multiple functions have also been developed and employed for the separation or fractionation of bioactive compounds. The hybrid electrodialysis (ED)-UF membrane process, for example has been used to provide a solution for the separation of biomolecules with similar molecular weights but different surface electrical properties. In contrast, the affinity membrane technology is shown to have the advantages of increasing the separation efficiency at low operational pressures through selectively adsorbing bioactive compounds during the filtration process. Conclusion: Individual membranes or membrane arrays are effectively used to separate bioactive compounds or achieve multiple fractionation of them with different molecule weights or sizes. Pressure driven membrane processes are highly efficient and widely used. Membrane fouling, especially irreversible organic and biological fouling, is the inevitable problem. Multifunctional membranes and affinity membranes provide the possibility of effectively separating bioactive compounds that are similar in sizes but different in other physical and chemical properties. Surface modification methods are of great potential to increase membrane separation efficiency as well as reduce the problem of membrane fouling. Developing membranes and optimizing the operational parameters specifically for the applications of separation of various bioactive compounds should be taken as an important part of ongoing or future membrane research in this field.

scholarly journals Experimental and Numerical Investigation on the Perforation Resistance of Double-Layered Metal Shield under High-Velocity Impact of Armor-Piercing Projectiles

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 626
Author(s):  
Riccardo Scazzosi ◽  
Marco Giglio ◽  
Andrea Manes
Keyword(s):  
High Strength Steel ◽  
Steel Plate ◽  
Experimental Studies ◽  
Practical Interest ◽  
High Strength ◽  
Experimental Tests ◽  
Element Model ◽  
Transportation Systems ◽  
Metal Shield ◽  
Softening Parameter

In the case of protection of transportation systems, the optimization of the shield is of practical interest to reduce the weight of such components and thus increase the payload or reduce the fuel consumption. As far as metal shields are concerned, some investigations based on numerical simulations showed that a multi-layered configuration made of layers of different metals could be a promising solution to reduce the weight of the shield. However, only a few experimental studies on this subject are available. The aim of this study is therefore to discuss whether or not a monolithic shield can be substituted by a double-layered configuration manufactured from two different metals and if such a configuration can guarantee the same perforation resistance at a lower weight. In order to answer this question, the performance of a ballistic shield constituted of a layer of high-strength steel and a layer of an aluminum alloy impacted by an armor piercing projectile was investigated in experimental tests. Furthermore, an axisymmetric finite element model was developed. The effect of the strain rate hardening parameter C and the thermal softening parameter m of the Johnson–Cook constitutive model was investigated. The numerical model was used to understand the perforation process and the energy dissipation mechanism inside the target. It was found that if the high-strength steel plate is used as a front layer, the specific ballistic energy increases by 54% with respect to the monolithic high-strength steel plate. On the other hand, the specific ballistic energy decreases if the aluminum plate is used as the front layer.

scholarly journals Thermal Inertia Characterization of Multilayer Lightweight Walls: Numerical Analysis and Experimental Validation

2021 ◽  
Vol 11 (11) ◽  
pp. 5008
Author(s):  
Juan José del Coz-Díaz ◽  
Felipe Pedro Álvarez-Rabanal ◽  
Mar Alonso-Martínez ◽  
Juan Enrique Martínez-Martínez
Keyword(s):  
Lightweight Concrete ◽  
Thermal Flux ◽  
Experimental Studies ◽  
Thermal Inertia ◽  
Transient State ◽  
Experimental Tests ◽  
Building Design ◽  
Experimental Methodology ◽  
Improve Energy Efficiency ◽  
Concrete Blocks

The thermal inertia properties of construction elements have gained a great deal of importance in building design over the last few years. Many investigations have shown that this is the key factor to improve energy efficiency and obtain optimal comfort conditions in buildings. However, experimental tests are expensive and time consuming and the development of new products requires shorter analysis times. In this sense, the goal of this research is to analyze the thermal behavior of a wall made up of lightweight concrete blocks covered with layers of insulating materials in steady- and transient-state conditions. For this, numerical and experimental studies were done, taking outdoor temperature and relative humidity as a function of time into account. Furthermore, multi-criteria optimization based on the design of the experimental methodology is used to minimize errors in thermal material properties and to understand the main parameters that influence the numerical simulation of thermal inertia. Numerical Finite Element Models (FEM) will take conduction, convection and radiation phenomena in the recesses of lightweight concrete blocks into account, as well as the film conditions established in the UNE-EN ISO 6946 standard. Finally, the numerical ISO-13786 standard and the experimental results are compared in terms of wall thermal transmittance, thermal flux, and temperature evolution, as well as the dynamic thermal inertia parameters, showing a good agreement in some cases, allowing builders, architects, and engineers to develop new construction elements in a short time with the new proposed methodology.

scholarly journals Improvement of Biogas Quality and Quantity for Small-Scale Biogas-Electricity Generation Application in off-Grid Settings: A Field-Based Study

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3088
Author(s):  
Henry Wasajja ◽  
Saqr A. A. Al-Muraisy ◽  
Antonella L. Piaggio ◽  
Pamela Ceron-Chafla ◽  
Purushothaman Vellayani Aravind ◽  
...  
Keyword(s):  
Electricity Generation ◽  
Relevant Literature ◽  
Electrical Power ◽  
Process Efficiency ◽  
Electricity Production ◽  
Small Scale ◽  
Buffer System ◽  
Biogas Plants ◽  
Operational Practices ◽  
Pre Treatment

Small-scale electrical power generation (<100 kW) from biogas plants to provide off-grid electricity is of growing interest. Currently, gas engines are used to meet this demand. Alternatively, more efficient small-scale solid oxide fuel cells (SOFCs) can be used to enhance electricity generation from small-scale biogas plants. Most electricity generators require a constant gas supply and high gas quality in terms of absence of impurities like H2S. Therefore, to efficiently use the biogas from existing decentralized anaerobic digesters for electricity production, higher quality and stable biogas flow must be guaranteed. The installation of a biogas upgrading and buffer system could be considered; however, the cost implication could be high at a small scale as compared to locally available alternatives such as co-digestion and improved digester operation. Therefore, this study initially describes relevant literature related to feedstock pre-treatment, co-digestion and user operational practices of small-scale digesters, which theoretically could lead to major improvements of anaerobic digestion process efficiency. The theoretical preamble is then coupled to the results of a field study, which demonstrated that many locally available resources and user practices constitute frugal innovations with potential to improve biogas quality and digester performance in off-grid settings.

Pre-Treatment Experimental Study of Organic Acid: An Alternative Means to Overcome Inorganic Scale Build-Up Problem in Deep Well

2021 ◽  
Author(s):  
Bagus Muliadi Nasution ◽  
Andrew Yonathan ◽  
Muthi Abdillah ◽  
Wang Zhen
Keyword(s):  
Hydrochloric Acid ◽  
Formic Acid ◽  
Organic Acid ◽  
Corrosion Inhibitor ◽  
Corrosion Test ◽  
Oil And Gas ◽  
Experimental Studies ◽  
Oil And Gas Industry ◽  
Scale Inhibitor ◽  
Pre Treatment

Abstract Organic acid has been widely applied for inorganic scale treatment in oil and gas industry including well stimulation and scale inhibitor. Thanks to its low corrosivity and slower reaction rate with rock, organic acid is considered to offer better performance comparing to strong acid - Hydrochloric Acid (HCl). Yet, proper treatment requires vigorous analysis and experiment in order to meet foremost expectations. Besides, mistreatment of scale could result in formation damage including clay precipitation. Pre-treatment experiments were performed on Zelda field at South East Sumatera block, that has faced with scale problem for ages. Water sample was taken from flowing Zelda A-08 well to be analyzed for mineral's saturation level. Scale was extracted from three sources including tubing, sand bailer, and Electrical Submersible Pump (ESP) of Zelda A-08. Those scale were treated in X-Ray Powder Diffraction (XRD) for mineral composition, and solubility test that utilized two types of acid system - formic acid (HCOOH) and hydrochloric acid (HCl) for comparison. Anti-swelling test and corrosion test were performed to examine the effectiveness of clay stabilizer and corrosion inhibitor. As for carbonate analysis, both formic acid 9% and HCl 15% have comparable solubility (98.17% vs 98% for tubing's scale, 91.86% vs 82.79% for ESP's scale, and 70.30% vs 68.07% for sand bailer's scale). Yet, longer reaction is carried out by formic acid 9% (1 hour) comparing to HCl 15% (18 minutes). For silicate analysis, HF-formic acid provided the higher solubility than HF-HCl (8.34% vs 5.67% for ESP's scale and 30.48% vs 25.68% for sand bailer's scale). On anti-swelling test, by reducing swelling tendency up to 62.6%, it proves that examined clay stabilizer works perfectly against swelling potential of clay, despite of high swelling tendency of sand bailer's scale (25.8%). On corrosion test, adding on corrosion inhibitor (pyridine-based) into solution results in regular HCl 15% has corrosion rate 26.279 g/m2.h which is much higher (300%) than HF-HCl (7.977 g/m2.h) and HF-formic acid (8.229 g/m2.h). Based on pre-treatment test, formic acid 9% together with examined corrosion inhibitor and clay stabilizer, can be used as an alternative to regular HCl 15% for stimulation purpose where more areas will be covered that previously left unreachable by regular acid 15%. In addition, potentially more effective squeezed scale inhibitor using organic acid can also be achieved by performing further experiments. The method presented in this paper for pre-treatment experimental studies of organic acid can provide engineers with intensive guide to meet the best result of organic acid treatment.

Sign in / Sign up

Export Citation Format

Share Document