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Physicochemical Parameters and Trace Metal in Marine Sediment from Bargny Coast (Senegal)
Birame Ndiaye,
Momar Ndiaye,
Benita Perez Cid,
Abdoulaye Diop,
Ibrahima Diagne,
Dame Cisse,
Cheikh Tidiane Dione,
Maoudo Hane,
Mame Mor Dione,
Sitor Diouf,
Seydou Ba
Issue:
Volume 10, Issue 5, October 2022
Pages:
114-119
Received:
1 August 2022
Accepted:
19 August 2022
Published:
16 September 2022
DOI:
10.11648/j.ajac.20221005.11
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Abstract: Marine sediments samples from Bargny coast (Senegal) were analyzed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The microwave acid digestion was also employed for metals (Cd, Pb, Cr, As) determination. The physicochemical parameters (pH, temperature, salinity, electrical conductivity) measured complied with European water standards. Fine fraction (< 63 μm) of sediments was used for extraction and determination of metallic trace elements. This study shows the presence of metallic contaminants in the marine sediments of the Bargny area. The marine sediments samples analyzed show practically similar metal contents during three sampling periods. The analytical results show that content of metallic trace elements found in marine sediments was in the following order: As> Cr> Cd> Pb (µg/g). This pollution can be attributed to the two factories located in this area: a coal-fired power station factory and a cement production factory (SOCOCIM INDUSTRY). This study shows the possibility of using sediment as an indicator of pollution because of its high capacity to accumulate pollutants. The ANOVA statistical analysis of results shows significant differences between metal contents of sediments studied during different campaigns. The assessment shows that sediments of Bargny coast do not present any significant risk of toxicity for living organisms in this aquatic system.
Abstract: Marine sediments samples from Bargny coast (Senegal) were analyzed by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The microwave acid digestion was also employed for metals (Cd, Pb, Cr, As) determination. The physicochemical parameters (pH, temperature, salinity, electrical conductivity) measured complied with European water standards. Fi...
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Experimental Aspect and Theoretical Modelling of Aluminium Inhibition Corrosion by Vitamins B1, B3 and B6 in Chloric Acid Solution
Mamadou Yeo,
Mougo Andre Tigori,
M’Bouille Cisse,
Paulin Marius Niamien
Issue:
Volume 10, Issue 5, October 2022
Pages:
120-128
Received:
23 August 2022
Accepted:
6 September 2022
Published:
26 September 2022
DOI:
10.11648/j.ajac.20221005.12
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Abstract: Metal corrosion phenomenon is an important topic in many industries because of its consequences on industrial equipment. The purpose of this study was to investigate the inhibition potential of three vitamins on aluminum corrosion in 1M HCl using experimental and theoretical techniques. So, the inhibitive effect of three vitamins that are vitamin B1, B3 and B6 on aluminium corrosion in 1M hydrochloric acid solution was studied by gravimetric techniques and quantum chemical method based on density functional theory (DFT). Gravimetric proved that these compounds are excellent inhibitors in tested solution. Vitamins adsorption on aluminium surface obeys to modified Langmuir model or Villamil model. Thermodynamic adsorption parameters were determined and discussed. Kinetic study of aluminum dissolution in absence or presence of each inhibitor indicates that the addition of each vitamin in corrosive solution does not change dissolution reaction order which is zero order. Finally, it was found that quantum chemical and experimental calculations correlate and indicated that inhibition effect of investigated molecules is strongly related to EHOMO, ELUMO, and energy gap (DE).
Abstract: Metal corrosion phenomenon is an important topic in many industries because of its consequences on industrial equipment. The purpose of this study was to investigate the inhibition potential of three vitamins on aluminum corrosion in 1M HCl using experimental and theoretical techniques. So, the inhibitive effect of three vitamins that are vitamin B...
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Determination of Ternary Systems Bisphenol A-Water-Organic Solvent Interaction Parameters by Genetic Algorithm Approach
Adama Ouattara,
Bamba Lamine,
Yao Kouassi Benjamin,
Assidjo Nogbou Emmanuel
Issue:
Volume 10, Issue 5, October 2022
Pages:
129-140
Received:
25 August 2022
Accepted:
14 September 2022
Published:
26 September 2022
DOI:
10.11648/j.ajac.20221005.13
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Abstract: An equilibrium phase study is very important for the design, optimization, and control of transformation and separation operations. The investigation of liquid-liquid or liquid-vapor equilibrium has been the subject of much interest in the chemical and petrochemical industry in recent years. Optimizing separation processes is one of the most important areas of process design and numerous types of research both practical and theoretical. The objective of the present work is twofold. First, it involves relying on experimental work to determine data of the liquid-liquid equilibrium (conodals) of ternary systems: {Bisphenol A (1) + Water (2) + Butan-1-ol (3)}, {Bisphenol A (1) + Water (2) + Cyclohexanol (3)} and {Bisphenol A (1) + Water (2) + Cyclohexane (3)}. In the second objective, the experimental results described in the first part were used to calculate interaction parameters of thermodynamic models such as NRTL and UNIQUAC in each phase base on a genetic algorithm technique programmed on MATLAB software. The results of correlations obtained from the experimental equilibrium data for the ternary systems were compared with those obtained from experimental data. The analysis of the results shows a very good agreement between the experimental data and the results obtained after optimization that demonstrates the reliability of the estimated interaction parameters as well as the capacity of NRTL and UNIQUAC models. Therefore, one can retain that the optimization method by genetic algorithms is a reliable method for the design and the simulation of processes.
Abstract: An equilibrium phase study is very important for the design, optimization, and control of transformation and separation operations. The investigation of liquid-liquid or liquid-vapor equilibrium has been the subject of much interest in the chemical and petrochemical industry in recent years. Optimizing separation processes is one of the most import...
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Influence of Catalytic Supports on Methane Steam Reforming: A Short Review
Sani Nasiru Alhaji,
Haruna Anas,
Salisu Aliyu
Issue:
Volume 10, Issue 5, October 2022
Pages:
141-147
Received:
2 September 2022
Accepted:
21 September 2022
Published:
11 October 2022
DOI:
10.11648/j.ajac.20221005.14
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Abstract: Steam Methane Reforming (SMR) is by far one of the key industrial processes that can help in achieving green and sustainable energy. As a major source of hydrogen (the so called future and green fuel), valuable oxygenated chemicals and key reaction for solid oxide fuel cells, the process solely depends on the presence of a metal supported catalyst to carry out the conversion of the feeds. The methane steam reforming (MSR) reaction is one of the major hydrogen sources in the industry. It is a significant means of transforming natural gas into valuable liquid fuels and oxygenated chemicals catalytically. Several techniques such as the inclusion of promoters, the development of improved catalytic supports, and structural modification, among other things have been developed in the past decade with the target of improving the catalytic activity, coking resistance and thermal stability of SMR catalysts. Meanwhile, a number of innovative processes for more efficient and energy-saving SMR process have been investigated. In this case, an examination of the influence of catalyst supports on the catalytic SMR is presented to gain a useful understanding of the impacts of supports on the SMR. This review is design to give a brief summary on methane steam reforming reaction, its thermodynamics and kinetics and finally the influence of support materials on the activity of noble and non-noble active metals used in SMR.
Abstract: Steam Methane Reforming (SMR) is by far one of the key industrial processes that can help in achieving green and sustainable energy. As a major source of hydrogen (the so called future and green fuel), valuable oxygenated chemicals and key reaction for solid oxide fuel cells, the process solely depends on the presence of a metal supported catalyst ...
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Study of Esterification Between the Used Tire and Citric Acid Molecules
Andry Tahina Rabeharitsara,
Havosoa Andriamanantsoa,
Nambinina Richard Randriana,
Baholy Robijaona,
Hanitra Marie Ratsimba
Issue:
Volume 10, Issue 5, October 2022
Pages:
148-155
Received:
10 September 2022
Accepted:
26 September 2022
Published:
11 October 2022
DOI:
10.11648/j.ajac.20221005.15
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Abstract: The recovery and recycling of all used tires is a constant challenge in a century where respect for the environment is becoming increasingly important and a key success factor. The Environmental Protection Agency (EPA) has classified citric acid as “Generally Recognized as Safe – GRAS”, in consequence its use as raw material is beneficial for all and allowed to the study of its esterification with used tread tires. The tread tire samples utilized during all experimentations have 1.062wt.% of sulfur and they were characterized by titrations based on Boëhm titration such as its acid sites densities determined with NaOH-0.05N was 2.0421E-03 moles×g-1 and its basic sites densities determined by HCl-0.1N was 2.5984E-03 moles×g-1. Thus, the esterification with citric acid at 141°C under atmospheric pressure using a closed reflux assembly of the tire’s tread part was carried out such as the quantities of citric acid were in excess in comparison to the tire’s total sites quantities. A model molecule representative of the connections of the most important atoms in the tire was proposed and permitted to show the possible reactions-mechanisms occurring between the tire’s acid and basic sites and the citric acid molecules during their esterification together catalyzed by the protonic acid-H+ of the citric acid. It was demonstrated that the esterification between citric acid and tire’s acid/basic sites occurred efficiency whether on surface, whether in tire’s porous with a very important initial conversion of the sites until 90% only after 20mn. The calculated global observed speed constant of the esterification between citric acid and tire’s acid/basic sites is equal to 2.33L3×mol-3×h-1. It was noticed that during this esterification the citric acid esterified with the tire’s acid/basic sites was dehydrated and explained the formation of alkenes organic function which quantities increased even after 2 hours. Thereafter, these tire’s citric acid alkenes will form the first new sites and their addition reactions with citric acid molecules or dehydrated citric acid molecules gave citric acid polymers and/or poly-aromatics molecules which constituted the second new sites; their densities after 2 hours reactions were respectively 9.18E-04 moles×g-1 and 7.65E-04 moles×g-1. After 2 hours of reaction, a soft dark materials with precipitates dark grains were recovered.
Abstract: The recovery and recycling of all used tires is a constant challenge in a century where respect for the environment is becoming increasingly important and a key success factor. The Environmental Protection Agency (EPA) has classified citric acid as “Generally Recognized as Safe – GRAS”, in consequence its use as raw material is beneficial for all a...
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Theoretical Study of Reactivity and Stability of a Thiazoline Derivative Series by the Density Functional Theory Method
Nanou Tieba Tuo,
Bafetigue Ouattara,
Mamadou Guy Richard Kone,
Georges Stephane Dembele,
Doh Soro,
Fandia Konate,
Bibata Konate,
Nahosse Ziao
Issue:
Volume 10, Issue 5, October 2022
Pages:
156-163
Received:
1 September 2022
Accepted:
16 September 2022
Published:
24 October 2022
DOI:
10.11648/j.ajac.20221005.16
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Abstract: This reactivity and stability work was performed on six (6) Thiazoline derivatives using density functional theory at the B3LYP/6-31+ G (d, p) level. The aim was to determine the electrophilic and nucleophilic sites and the chemical behaviour of thiazolines. To do this, we calculated the fukui reactivity parameters (f+; f-), as well as the conceptual DFT reactivity parameters. The analysis of local descriptors and the molecular electrostatic potential map identified the nitrogen (N) atoms of the Thiazoline ring as the preferred electrophilic attack site (nucleophilic site) for the compound series. Moreover, the Natural Population Analysis (NPA) also corroborated this same information, that is to say the sulfur atoms (S) are electrophilic sites and the nitrogen atoms the nucleophilic sites of the compounds studied. Also, the sulfur atones that bind the linker were designated as the nucleophilic attack site (electrophilic site). The study of the boundary molecular orbitals, including energy gap (ΔE), electronegativity (χ), chemical hardness (η), and electrophilicity index (ω) allowed the chemical reactivity of Thiazoline derivatives to be described from the molecular properties. Thus, the Th3 molecule is the most stable, least reactive and hardest. Moreover, the Th3 compound is the one which gives the least electrons on all the studied molecules.
Abstract: This reactivity and stability work was performed on six (6) Thiazoline derivatives using density functional theory at the B3LYP/6-31+ G (d, p) level. The aim was to determine the electrophilic and nucleophilic sites and the chemical behaviour of thiazolines. To do this, we calculated the fukui reactivity parameters (f+; f-), as well as the conceptu...
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Inventory of Soil Pollution by Chemical Fertilizers in the Cotton Growing Area of Togo: Case of Kolo-Kope
Kokou Kossi,
Bafai Diyakadola Diheenane,
Tchegueni Sanonka,
Degbe Koffi Agbegnigan,
Koriko Moursalou,
Tchangbedji Gado
Issue:
Volume 10, Issue 5, October 2022
Pages:
164-169
Received:
1 October 2022
Accepted:
28 October 2022
Published:
31 October 2022
DOI:
10.11648/j.ajac.20221005.17
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Abstract: The search for higher and higher agricultural yields leads to the use of chemical fertilizers and phytosanitary products. The abusive or repeated use of these agricultural inputs results in soil, surface water and groundwater pollution. With the development of this new form of agriculture, the input of heavy metals to the soil has increased. Research on the fate of these pollutants in the environment is important. It is within this framework that this study was undertaken to evaluate the level of pollution due to trace metals in soils in the cotton growing zone in southern Togo. Soil samples were taken in cotton fields during the dry season. The first analyses led to the determination of some physico-chemical characteristics of the soils including pH, granulometry as well as the cation exchange capacity (CEC). These first two parameters revealed that the soil was slightly acidic and essentially clayey in texture. Then, after mineralization of the soils, the solutions obtained were analyzed with an atomic absorption spectrophotometer (AAS). Twelve (12) metals (V, Cd, Hg, Na, Cr, Ni, Sn, Pb, As, Zn, Cu, Fe) were studied. The concentration of metal ions varies from 0.0038 mg/kg (for vanadium to 5647.31 mg/kg (for iron). The order of abundance for the elements is as follows: V< Ni < Cr < Cd < Na < Hg < Sn < As < Pb < Cu < Zn < Fe. The values found during the analyses compared to the French standards (0.7mg/kg for Cd and 60 mg/kg for Pb) shows that no investigation threshold is reached.
Abstract: The search for higher and higher agricultural yields leads to the use of chemical fertilizers and phytosanitary products. The abusive or repeated use of these agricultural inputs results in soil, surface water and groundwater pollution. With the development of this new form of agriculture, the input of heavy metals to the soil has increased. Resear...
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