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Activity Coefficients of Nitrate Uranyl and Nitric Acid in Mixed Solutions
Alexander Ochkin,
Alexey Merkushkin,
Dmitriy Gladilov
Issue:
Volume 10, Issue 1, February 2022
Pages:
1-6
Received:
10 May 2021
Accepted:
3 June 2021
Published:
12 January 2022
Abstract: Aqueous solutions are frequently used in chemical technology. So numerous reference books contain basic data on major properties of binary electrolyte solutions. Usually they include densities, molar or molal concentrations, activity coefficients, water activities and sometimes osmotic coefficients. Unfortunately, most solutions are mixed ones. Therefore, it is necessary to use data of binary solutions in order to calculate thermodynamic properties of mixed solutions. For example, the aqueous phase in extraction reprocessing of nuclear reactor fuel can be considered as mixed solution of nitric acid and uranyl nitrate in first approximation. Thus, in order to calculate equilibrium during extraction of uranium with TBP it is necessary to create calculations algorithm of activity coefficients of uranyl nitrate and nitric acid with different ratios of their concentrations. Usually the integration of Gibbs-Duhem equation with some conditions is used. The first ones to offer this approach were Mc Kay and Perring in 1953. Practical implementation shows that it is recommended to integrate the equation under isopiestic conditions, meaning under constant osmotic coefficients. Zdanoskiy’s rule states, that the sum of ratios of molal concentrations in mixed solution to molal concentrations in binary solutions is equal to 1. Mikulin’s equations for the systems that abide by Zdanovskiy’s rule allow calculations of molal coefficients of activity for such systems. Molal activity coefficients of nitrate uranyl (0.1-2.0 mole/kg) and nitric acid (0-5.0 mole/kg) in mixed solutions have been calculated using Zdanovskiy’s rule and Mikulin·s equations. Analytical equations were found in order to calculate these values under different concentrations. Literature data of activity coefficients for binary solutions can be combined with calculation results from equations.
Abstract: Aqueous solutions are frequently used in chemical technology. So numerous reference books contain basic data on major properties of binary electrolyte solutions. Usually they include densities, molar or molal concentrations, activity coefficients, water activities and sometimes osmotic coefficients. Unfortunately, most solutions are mixed ones. The...
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Modelling and Optimization of Biodiesel Production Process Parameters from Jansa Seed Oil (Cussonia bateri) Using Artificial Neural Network
Chinwe Priscilla Okonkwo,
Vincent Ishmael Egbulefu Ajiwe,
Ebuka Chidiebere Mmaduakor,
Njideka Veronica Nwankwo
Issue:
Volume 10, Issue 1, February 2022
Pages:
7-14
Received:
14 January 2022
Accepted:
4 February 2022
Published:
16 February 2022
Abstract: Biodiesel has been referred to as a perfect substitute for diesel fuel due to its numerous promising properties. They are renewable, clean, increases energy security, improves the environment and air quality and also provides some good safety benefits. This study is focused on the investigation of the use of natural heterogeneous catalysts for production of biodiesel from jansa seed oil, as well as the implementation of artificial neural network (ANN) for the prediction of biofuel yield and process parameters. The biodiesel was produced through transesterification reaction by reacting jansa seed oil (FFA) with methanol (alcohol) to yield methyl ester. Waste periwinkle shell was prepared in 3 different forms; raw, calcined and acidified. The percentage yield of the methyl ester obtained were calculated and tabulated. The process parameters considered were methanol-oil mole ratio, catalyst concentration, agitation speed, reaction temperature and reaction time. The results of this research work revealed that the calcined periwinkle shell catalyst produced higher yield of biodiesel, compared to the yield obtained from the raw and acidified catalyzed process. The properties of the fatty acid methyl esters were within the standard range. The experimental and predicted yield were marginally the same. Hence, the model accurately predicted the yield with acceptable coefficient of determination and low mean squared error (MSE). The results demonstrate the flexibility of ANN model and the improvement of the model in terms of performance prediction when solving problems with stochastic dataset, especially the transesterification of biodiesel.
Abstract: Biodiesel has been referred to as a perfect substitute for diesel fuel due to its numerous promising properties. They are renewable, clean, increases energy security, improves the environment and air quality and also provides some good safety benefits. This study is focused on the investigation of the use of natural heterogeneous catalysts for prod...
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Ranges and Fitting Ratios of Natural Aggregates for a Sustainable and Effective Fe°/Sand/Pozzolan Ternary Device Using Orange Methyl
Suzanne Makota S. N.,
Nguemo Wekam Eleonore Armele,
Dipita Kolye Ernest Yves Herliche,
Nassi Achille
Issue:
Volume 10, Issue 1, February 2022
Pages:
15-27
Received:
24 January 2022
Accepted:
10 February 2022
Published:
25 February 2022
Abstract: The remediation effectiveness of a Fe°/Sand/Pozzolan (Fe°/S/Pz) ternary device using an azo-dye for characterization is demonstrated herein. Optimal operating conditions, which specify the proportions of solid materials, such as iron (Fe°), sand (S), and pozzolan (Pz), in the reactive zone (RZ), are essential factors for the performance of such heterogeneous devices. Thus, the operative indicator orange methyl (OM) of 2 mg/L was used. Performance parameters such as pH, released iron of the collected water, flow rate, and fading power were measured using filter devices containing (1) 100% Fe°, (2) 25%/75% Fe°/S, (3) 25%/75% Fe°/Pz, (4) 25%/0%/75% Fe°/S/Pz, (5) 25%/25%/50% Fe°/S/Pz and (6) 25%/50%/25% Fe°/S/Pz for a correlation of proportions, reactivity, and performance. The experiments lasted thirty (30) days per device. It turns out that ranges of 25% ≤ % Fe° ≤ 60%, 25% ≤ %S ≤ 50%, and 25% ≤ %Pz ≤ 50% are quite enough. The ternary device, in ratios of 25%/50%/25% Fe°/S/PZ, is an excellent decontaminant of orange methyl OM, with regulation of pH and residual iron levels, for acceptable flows. There are therefore beneficial effects of the association of a non-expansive porous material with Fe°-based filters to delay clogging by collecting corrosion products (CPs). 25%/50%/25% Fe°/S/PZ device allow to reduce greatly the proportion of iron in the reactive zone (RZ) since pure iron devices are not recommended due to clogging. 25% ≤ % Fe° ≤ 60%, 25% ≤ %S ≤ 50%, and 25% ≤ %Pz ≤ 50% could provide a necessary framework for all Fe°-bed filters.
Abstract: The remediation effectiveness of a Fe°/Sand/Pozzolan (Fe°/S/Pz) ternary device using an azo-dye for characterization is demonstrated herein. Optimal operating conditions, which specify the proportions of solid materials, such as iron (Fe°), sand (S), and pozzolan (Pz), in the reactive zone (RZ), are essential factors for the performance of such het...
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Natural Charcoal in Water Treatment Through Metal Bed Filters Fe°/S/Pz/C: The Concept of Wood-Energy-Sanitation
Dipita Kolye Ernest Yves Herliche,
Suzanne Makota S. N.,
Mbarga Landry Valère,
Mintang Fongang Ulrich Armel,
Dika Manga Joseph Marchand,
Nassi Achille
Issue:
Volume 10, Issue 1, February 2022
Pages:
28-37
Received:
1 February 2022
Accepted:
16 February 2022
Published:
28 February 2022
Abstract: The concept of the W.E.S (Wood-Energy-Sanitation) for raising awareness among populations far from the distribution networks of drinking water is established. The process of decontaminating filter columns made up of natural charcoal (NC) as porous non-expansive absorbent/adsorbent materials such as pozzolan (Pz) is experienced. The contribution of the NC to the filtering power of the Fe°-based filters, whose decontamination involves the electrochemical oxidation processes of Fe°, and corrosion products (CPs) that can cause a blockage of the reactive surface is studied. To do this, seven systems were tested with reactive zones (RZ) respectively consisting of (1) C (pure NC), (2) Pz (pure Pozzolan), (3) Fe°/C (iron/NC), (4) Fe°/Pz (iron/Pozzolan), (5) Fe°/S/C (Iron/Sand/NC), (6) Fe°/S/Pz (Iron/Sand/Pozzolan), (7) Fe°/S/Pz/C (Iron/Sand/Pozzolan/NC). OM (orange methyl) of 2 mg/L concentration was used as operative indicator. The experiments lasted 40 days per device. Performance parameters such as pH, residual iron, OM discoloration and flow rate were measured. As a result, it appears that the NC alone or associated in the Fe°/C, Fe°/S/C devices has a better filtering power than the Pz. The combination of NC and Pz in the same Fe°/S/Pz/C device improves strikingly the results, such as Fe°/S/Pz/C > Fe°/S/C > Fe°/S/Pz > Fe°/C > Fe°/Pz > C > Pz. Combining two non-expansive porous materials in the RZ stabilizes the Fe°/S/Pz/C-filter and improves its lifespan.
Abstract: The concept of the W.E.S (Wood-Energy-Sanitation) for raising awareness among populations far from the distribution networks of drinking water is established. The process of decontaminating filter columns made up of natural charcoal (NC) as porous non-expansive absorbent/adsorbent materials such as pozzolan (Pz) is experienced. The contribution of ...
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