scholarly journals THE USE OF FLY ASH AND ZEOLITE MIXTURE AS BACKFILL MATERIAL IN THE RADIOACTIVE WASTE REPOSITORY

2010 ◽  
Vol 5 (3) ◽  
pp. 302-308
Author(s):  
Herry Poernomo ◽  
Noor Anis Kundari ◽  
Burhani J W
Keyword(s):  
Fly Ash ◽  
Radioactive Waste ◽  
Dispersion Coefficient ◽  
Nitrate Solution ◽  
Fixed Bed ◽  
Weight Ratio ◽  
Weight Percent ◽  
Backfill Material ◽  
Fly Ash Zeolite ◽  
Effective Dispersion

An investigation of the contribution of fly ash in the fly ash-zeolite mixture as the backfill material on the shallow land burial of radioactive waste has been done. The experiment objective is to know the effect of zeolite particle size and fly ash-zeolite weight ratio on physical properties such as permeability (K) and dispersion characteristic such as effective dispersion coefficient (De) in the fly ash-zeolite form as backfill material. The experiment was carried out by the fixed bed method in the column filled by the fly ash-zeolite mixture with a fly ash-to-zeolite weight percent ratio of 100/0, 80/20, 60/40, 40/60, 20/80, 0/100 in the water saturated condition flown by uranyl nitrate solution at concentration (Co) of 500 ppm. The concentration of uranium in the effluents in interval 15 minutes represented as Ct was analyzed by spectrophotometer, then using Co and Ct, data effective dispersion coefficient (De) in the backfill material were determined. The experiment data showed that -400 mesh fly ash and -70+80 mesh zeolite on fly ash-to-zeolite with weight percent ratio of 40/60 with K = 5.00x10-5cm/second and De = 1.11.10-5 cm2/second can be used as backfill material. Keywords: backfill material, fly ash, radioactive waste, zeolite

scholarly journals DISPERSION AND SORPTION CHARACTERISTICS OF URANIUM IN THE ZEOLITE-QUARTZ MIXTURE AS BACKFILL MATERIAL IN THE RADIOACTIVE WASTE REPOSITORY

2010 ◽  
Vol 6 (3) ◽  
pp. 261-267
Author(s):  
Herry Poernomo ◽  
Noor Anis Kundari
Keyword(s):  
Particle Size ◽  
Radioactive Waste ◽  
Nitrate Solution ◽  
Fixed Bed ◽  
Weight Ratio ◽  
Weight Percent ◽  
Raw Material ◽  
Radioactive Waste Repository ◽  
Backfill Material ◽  
Waste Repository

The experiment of sorption and dispersion characteristics of uranium in the zeolite-quartz mixture as candidate of raw material of backfill material in the radioactive waste repository has been performed. The objective is to know the effect of zeolite and quartz grain size on the zeolite-to-quartz weight ratio that gives porosity (ε), permeability (K), and dispersivity (α) of uranium in the zeolite-quartz mixture as backfill material. The experiment was carried out by fixed bed method in the column filled by the zeolite-quartz mixture with zeolite-to-quartz weight percent ratio of 100/0, 80/20, 60/40, 40/60, 20/80, 0/100 wt. % in the water saturated condition flowed by uranyl nitrate solution of 500 ppm concentration (Co) as uranium simulation which was leached from immobilized radioactive waste in the repository. The concentration of uranium in the effluents represented as Ct were analyzed by spectrophotometer Corning Colorimeter 253 every 15 minutes, then using Co and Ct uranium dispersivity (α) in the backfill material was determined. The experiment data shown that 0.196 mm particle size of zeolite and 0.116 mm particle size of quartz on the zeolite-to-quartz weight ratio of 60/40 wt. % with ε = 0.678, K = 3.345x10-4 cm/second, and α = 0.759 cm can be proposed as candidate of raw material of backfill material in the radioactive waste repository.   Keywords: backfill material, quartz, radioactive waste, zeolite

scholarly journals PHYSICAL CHARACTERISTICS OF FLY ASH NANO PARTICLES AS BACKFILL ON THE RADIOACTIVE WASTE REPOSITORY

2010 ◽  
Vol 9 (1) ◽  
pp. 28-36
Author(s):  
Herry Poernomo
Keyword(s):  
Fly Ash ◽  
Radioactive Waste ◽  
Migration Rate ◽  
Nitrate Solution ◽  
Fixed Bed ◽  
Nano Particles ◽  
Radioactive Waste Repository ◽  
Fly Ash Zeolite ◽  
Backfill Materials ◽  
Waste Repository

Characterization of fly ash nano particles as backfilled material candidate in the radioactive waste repository has been done. The objective of this research is to determine the permeability (K) and migration rate (Vr) of uranium in the backfilled material of fly ash, zeolite, and zeolite + fly ash mixtures. The experiment was carried out by the fixed bed method in a column contains fly ash, or zeolite, or zeolite+fly ash mixtures. It was filled with the saturated water and was flown by uranyl nitrate solution of 500 ppm as the simulated uranium. The uranium effluents was sampled in every 15 minutes and it was analyzed using spectrometer. The concentration of which represented as Ct and by using concentration profile of Co/Ct, then Vr of uranium in the backfilled material can be determined. The experiment result showed that ≤ 38 mm of fly ash particles sizes could improve the characteristic feature of 196 mm of zeolite sizes as backfilled material with the decreasing permeability values from Kzeolite = 4.06x10-3 cm/s to Kzeolite+fly ash = 5.00x10-5 cm/s and the decreasing of the migration rate from Vr zeolite = 1.65x10-4 cm/s to Vr zeolite+fly ash  = 2.91x10-6 cm/second.   Keywords: fly ash, zeolite, backfill materials, uranium migration, radioactive waste repository

scholarly journals BENTONITE-QUARTZ SAND AS THE BACKFILL MATERIALS ON THE RADIOACTIVE WASTE REPOSITORY

2010 ◽  
Vol 5 (2) ◽  
pp. 115-120
Author(s):  
Raharjo Raharjo
Keyword(s):  
Radioactive Waste ◽  
Quartz Sand ◽  
Nitrate Solution ◽  
Fixed Bed ◽  
Weight Percent ◽  
Retardation Factor ◽  
Backfill Materials ◽  
Uranium Migration ◽  
Water Saturated ◽  
Bentonite Particle

An investigation of the contribution of quartz sand in the bentonite mixture as the backfill materials on the shallow land burial of radioactive waste has been done. The experiment objective is to determine the effect of quartz sand in a bentonite mixture with bentonite particle sizes of -20+40, -40+60, and -60+80 mesh on the retardation factor and the uranium dispersion in the simulation of uranium migration in the backfill materials. The experiment was carried out by the fixed bed method in the column filled by the bentonite mixture with a bentonite-to-quartz sand weight percent ratio of 0/100, 25/75, 50/50, 75/25, and 100/0 on the water saturated condition flown by uranyl nitrate solution at concentration (Co) of 500 ppm. The concentration of uranium in the effluents in interval 15 minutes represented as Ct was analyzed by spectrophotometer, then using Co and Ct, retardation factor (R) and dispersivity () were determined. The experiment data showed that the bentonite of -60+80 mesh and the quartz sand of -20+40 mesh on bentonite-to-quartz sand with weight percent ratio of 50/50 gave the highest retardation factor and dispersivity of 18.37 and 0.0363 cm, respectively.   Keywords: bentonite, quartz sand, backfill materials, radioactive waste  

scholarly journals PRELIMINARY STUDY OF THE UTILIZATION OF THE FLY ASH FROM COAL-FIRED POWER PLANT FOR IMMOBILIZATION OF RADIOACTIVE WASTE

2011 ◽  
Vol 11 (3) ◽  
pp. 258-266 ◽  
Author(s):  
Herry Poernomo
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Power Plant ◽  
Radioactive Waste ◽  
Weight Ratio ◽  
Pozzolanic Material ◽  
Medium Level ◽  
Study Characteristics ◽  
Preliminary Study

Preliminary study of the utilization of the fly ash from coal-fired power plant for immobilizing simulated radioactive waste has been done. The objective of this research was to study characteristics of pozzolanic material of the fly ash from coal-fired power plant as substitute of compactor material for immobilizing simulated radioactive waste. The experiment was carried out by mixing of the compactor materials such as (cement + lime), (cement + fly ash), (cement + fly ash + lime), (fly ash + lime) with Na2SO4 225 g/L and KCl 4.6 g/L as simulation of evaporator concentrate according to reference waste form no. 1 on characterization of low and medium-level radioactive waste forms in the EUR 9423-EN. Each mixture of compactor materials solidified for 14 days, 21 days, and 28 days. Solidified result was monolith, and then its compressive strength, water absorption, and porosity were tested. The experiment result showed that the best of the compactor materials on the immobilizing simulated radioactive waste was cement of 30% (wt), fly ash of 20% (wt), and lime of 20% (wt) with compressive strength of monolith of 1512.7 N/cm2. The condenser substance on the weight ratio of fly ash/lime of 20/50 - 60/10 % (wt) as pozzolanic substance could be used for immobilizing simulated radioactive waste by compressive strength of monoliths of 345 - 610.4 N/cm2. Minimum compressive strength of monolith from radioactive waste cementation according to IAEA is 320 N/cm2, hence compressive strength of monoliths from this experiment can be expressed enough well.

scholarly journals SORPTION AND DISPERSION OF STRONTIUM RADIONUCLIDE IN THE BENTONITE-QUARTZ-CLAY AS BACKFILL MATERIAL CANDIDATE ON RADIOACTIVE WASTE REPOSITORY

2010 ◽  
Vol 10 (3) ◽  
pp. 276-284 ◽  
Author(s):  
Herry Poernomo
Keyword(s):  
Grain Size ◽  
Radioactive Waste ◽  
Bentonite Clay ◽  
Weight Percent ◽  
Raw Material ◽  
Dispersion Characteristics ◽  
Sorption Characteristic ◽  
Radioactive Waste Repository ◽  
Backfill Material ◽  
Waste Repository

The experiment of sorption and dispersion characteristics of strontium in the mixture of bentonite-quartz, clay-quartz, bentonite-clay-quartz as candidate of raw material for backfill material in the radioactive waste repository has been performed. The objective of this research is to know the grain size effect of bentonite, clay, and quartz on the weight percent ratio of bentonite to quartz, clay to quartz, bentonite to clay to-quartz can be gives physical characteristics of best such as bulk density (rb), effective porosity (e), permeability (K), best sorption characteristic such as distribution coefficient (Kd), and best dispersion characteristics such as dispersivity (a) and effective dispersion coefficient (De) of strontium in the backfill material candidate. The experiment was carried out in the column filled by the mixture of bentonite-quartz, clay-quartz, bentonite-clay-quartz with the weight percent ratio of bentonite to quartz, clay to quartz, bentonite to clay to quartz of 100/0, 80/20, 60/40, 40/60, 20/80, 0/100 respectively at saturated condition of water, then flowed 0.1 N Sr(NO3)2 as buffer solution with tracer of 0.05 Ci/cm3 90Sr as strontium radionuclide simulation was leached from immobilized radioactive waste in the radioactive waste repository. The concentration of 90Sr in the effluents represented as Ct were analyzed by Ortec b counter every 30 min, then by using profile concentration of Co and Ct, values of Kd, a and De of 90Sr in the backfill material was determined. The experiment data showed that the best results were -80+120 mesh grain size of bentonite, clay, quartz respectively on the weight percent ratio of bentonite to clay to quartz of 70/10/20 with physical characteristics of rb = 0.658 g/cm3, e = 0.666 cm3/cm3, and K = 1.680x10-2 cm/sec, sorption characteristic of Kd = 46.108 cm3/g, dispersion characteristics of a = 5.443 cm, and De = 1.808x10-03 cm2/sec can be proposed as candidate of raw material of backfill material in the radioactive waste repository.

Reuse of Fried Oil to Obtain Biodiesel: Zeolites Y as a Catalyst

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
A. Brito ◽  
M. E. Borges ◽  
R. Arvelo ◽  
F. Garcia ◽  
M. C. Diaz ◽  
...  
Keyword(s):  
Fixed Bed ◽  
Weight Ratio ◽  
Degree Of Conversion ◽  
Transesterification Reaction ◽  
Molar Ratio ◽  
Catalytic Reactor ◽  
Reaction Products ◽  
Waste Oil ◽  
Catalytic Effects ◽  
Fried Oil

The transesterification reaction is the most utilized process to obtain biodiesel. Fried oil transesterification reactions with methanol have been studied using several zeolites Y and interchanged with CsCl and KOH. The reaction has been carried out both in a slurry reactor and a fixed bed catalytic reactor. The catalytic effects of zeolites have been tested within a temperature range of 60-476°C, 2.5-5% catalyst/waste oil weight ratio, and 6:1 - 100:1 methanol/oil molar ratio. Cosolvents (THF, n-hexane) in the reaction feedstock effect have also been studied as well as catalyst regeneration effects. Viscosity of both the oil and the transesterification reaction products was determined as an initial guide to investigate the degree of conversion to biodiesel as well as FAME content by GC. When interchanged zeolites are used conversions are improved, getting the best yields (98% FAME) for the Y756 zeolite interchanged with KOH. Viscosities of the reaction product obtained reached values next to diesel standard ones.

Gaseous dispersion in laminar flow through a circular tube

1965 ◽  
Vol 284 (1399) ◽  
pp. 540-550 ◽  
Keyword(s):  
Circular Tube ◽  
Dispersion Coefficient ◽  
Straight Tube ◽  
Laminar Regime ◽  
Thermal Conductivity Detector ◽  
Longitudinal Dispersion Coefficient ◽  
Dispersion Coefficients ◽  
Effective Dispersion ◽  
Flow Through ◽  
Gaseous Dispersion

The dispersion of a pulse of ethylene injected into nitrogen, flowing in the laminar régime through straight and curved tubes, has been investigated at pressures of 1.0 and 4.4 atm. From the study of the concentration profiles with a thermal conductivity detector (katharometer) it is found that the experimental results for gas velocities between 1.00 and 16.00 cm/s agree well with the analytical solution to this problem for a straight tube given by Sir Geoffrey Taylor and extended by Aris. In particular, at low velocities, the effective dispersion coefficients tend to the molecular diffusivities. The presence of a bend slightly reduces the effective longitudinal dispersion coefficient and the introduction of constrictions enhances it. Data are also given on a number of other gas pairs. It is concluded that measurements of dispersion provide an accurate and simple way of studying diffusion in gas mixtures.

Effect Multiple Addition (TiO2 and Fly Ash) on Wear Behavior and Hardness of 2024 Al Alloy

2021 ◽  
Vol 1039 ◽  
pp. 201-208
Author(s):  
Ruaa A. Salman ◽  
Naser K. Zedin
Keyword(s):  
Wear Resistance ◽  
Fly Ash ◽  
Wear Rate ◽  
Wear Behavior ◽  
Weight Percent ◽  
Al Alloy ◽  
Sliding Speed ◽  
Multiple Addition

This research is devoted to study the effect of addition (2%) TiO2 with different weight percent of fly ash particulate (0, 2, 4, 6%) to 2024 Al alloy on the wear behavior and hardness. The alloy was fabricated by the liquid metallurgy method. The results founds that the wear rate decreased from 0.55 with 0% fly ash to 0.18 at addition percentage of 6% fly ash. Also, the results reveal increasing the samples wear rate with increasing the load and loaded time. The rate of wear was decreased with increasing the sliding speed. Also, the values of hardness increased from 120VH to 160VH with rising the fly ash from 0% to 6%. Keywords: Fly Ash addition, TiO2, 2024 Al Alloy, Wear Resistance, Hardness.

Dispersion in steady and oscillatory flows through a tube with reversible and irreversible wall reactions

2005 ◽  
Vol 462 (2066) ◽  
pp. 481-515 ◽  
Author(s):  
Chiu-On Ng
Keyword(s):  
Dispersion Coefficient ◽  
Tube Wall ◽  
Dispersion Model ◽  
Small Diameter ◽  
Chemical Species ◽  
Taylor Dispersion ◽  
Phase Partitioning ◽  
Dispersion Mechanism ◽  
Effective Dispersion ◽  
Number Flow

An asymptotic analysis is presented for the advection–diffusion transport of a chemical species in flow through a small-diameter tube, where the flow consists of steady and oscillatory components, and the species may undergo linear reversible (phase exchange or wall retention) and irreversible (decay or absorption) reactions at the tube wall. Both developed and transient concentrations are considered in the analysis; the former is governed by the Taylor dispersion model, while the latter is required in order to formulate proper initial data for the developed mean concentration. The various components of the effective dispersion coefficient, valid when the developed state is attained, are derived as functions of the Schmidt number, flow oscillation frequency, phase partitioning and kinetics of the two reactions. Being more general than those available in the literature, this effective dispersion coefficient incorporates the combined effects of wall retention and absorption on the otherwise classical Taylor dispersion mechanism. It is found that if the phase exchange reaction kinetics is strong enough, the dispersion coefficient is probably to be increased by orders of magnitude by changing the tube wall from being non-retentive to being just weakly retentive.

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