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Gravity and Surface Tension as Driving Forces of Electroosmosis
Issue:
Volume 11, Issue 4, December 2022
Pages:
85-90
Received:
13 September 2022
Accepted:
29 September 2022
Published:
11 October 2022
DOI:
10.11648/j.ajpc.20221104.11
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Abstract: It is generally believed that electroosmosis is comprehensively described by the corresponding Helmholtz-Smoluchowski equation. Consequently, this belief has contributed to the fact that electroosmosis is still viewed as occurring in a time-invariant aqueous medium characterized by constant viscosity and dielectric permeability. Considering the inevitable chemical and physical changes of electrolytes through which electric currents flow, the correctness of such an acceptation is questionable. In particular, it is unlikely that the viscosity and dielectric permeability of electrolytes, which are part of the Helmholtz-Smoluchowski equation for electroosmosis, do not change under the influence of electric currents. This, accordingly, raises the question: exactly what valuesof these parameters should be inserted into the given equation? So, even the specified variability of electrolytes under the action of electric currents immediately calls into question the feasibility of applying of the Helmholtz-Smoluchowski equation for electroosmosis. Unfortunately, the formal perfection of this very equation supports belief in its correctness, which masks its unacceptability, first of all – for practitioners. Furthermore, this very belief has contributed to the fact that electroosmosis is still perceived as an exclusively electrokinetic phenomenon and, therefore, does not even allow suspecting the involvement of non-electrical forces in it, which is false. In any case, both calculations and experimental results presented here show that the main driving force of typical electroosmosis is gravity. Moreover, the obtained experimental results allow assuming the participation of other non-electrical forcesin electroosmosis. Thus, it is shown here that the main driving forces of electroosmosis are forces of a non-electric nature, and therefore – that electroosmosis should not be perceived as a purely electrokinetic phenomenon. At the same time, attention is paid here both to the granular structure of anolytes and to the filamentary structure of catholytes; accordingly, it is proposed to consider this difference in structures as one of the factors determining the predominant direction of typical electroosmosis. Eventually, the multilayered structure of aqueous salt solutions is demonstrated here. Accordingly, it is proposed to take into account this feature when explaining the movement of water and aqueous solutions, including electroosmotic ones. After all, here it is proposed to agree that the Helmholtz-Smoluchowski equation for electroosmosis contributes to the spread of distorted views of this phenomenon.
Abstract: It is generally believed that electroosmosis is comprehensively described by the corresponding Helmholtz-Smoluchowski equation. Consequently, this belief has contributed to the fact that electroosmosis is still viewed as occurring in a time-invariant aqueous medium characterized by constant viscosity and dielectric permeability. Considering the ine...
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Use of Carbonaceous Materials Derived from Co-products of Lophira lanceolata for Adsorption Tests of Congo Red Dye
Elie Sogbochi,
Pierre Girods,
Guevara Nonviho,
Sebastien Fontana,
Yann Rogaume,
Dominique Codjo Koko Sohounhloue
Issue:
Volume 11, Issue 4, December 2022
Pages:
91-101
Received:
7 September 2022
Accepted:
29 September 2022
Published:
24 October 2022
DOI:
10.11648/j.ajpc.20221104.12
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Abstract: The present study aims to valorize the hulls of Lophira lanceolata, an agricultural by-product in Benin. This natural resource, which is abundant in tropical countries, including Benin, has so far been considered as a biodegradable waste and treated as such. However, it has adsorption properties that can be exploited by transforming it into activated carbon for various uses, including water purification. For this purpose, activated carbons have been developed from the said hulls chemically impregnated with phosphoric acid. The adsorption kinetics of red Congo on these activated carbons is governed by the pseudo-second order kinetic model. The adsorption isotherms of Congo red by the Langmuir model give adsorbed quantities varying between 1250 and 1666.67 mg.g-1, but this model is not credible to explain the mechanism. The Freundlich model is the most credible to explain the Congo red adsorption phenomenon. It indicates the cooperative and multilayer adsorption of Congo red on activated carbons. The thermodynamic study of the Congo red adsorption process shows that it is exothermic, spontaneous, and the Congo red molecules fixed are ordered on the surface of the activated carbons. Thus, it should be noted that the adsorbents produced can be used for the removal of anionic dyes in aqueous solution and effective at low concentrations.
Abstract: The present study aims to valorize the hulls of Lophira lanceolata, an agricultural by-product in Benin. This natural resource, which is abundant in tropical countries, including Benin, has so far been considered as a biodegradable waste and treated as such. However, it has adsorption properties that can be exploited by transforming it into activat...
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Biofuel Potentiality of Pineapple Peelings in the Presence of the Yeasts Saccharomyces cerevisiae and Saccharomyces carlsbergensis
Gbohaida Virginie,
Konfo Tetede Rodrigue Christian,
Nonviho Guevara,
Agbangnan Dossa Cocou Pascal,
Avlessi Felicien,
Sohounhloue Koko Codjo Dominique
Issue:
Volume 11, Issue 4, December 2022
Pages:
102-109
Received:
5 October 2022
Accepted:
24 October 2022
Published:
30 October 2022
DOI:
10.11648/j.ajpc.20221104.13
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Abstract: In pineapple industries and processing units, peelings constitute waste piled up in landfills and therefore cause real problems for environment. The present study aims to develop this available and neglected bioresource, through the study of the kinetics of its conversion into bioethanol by fermentation with a view to its use as a biofuel. To do this, the pineapple peelings juice was converted into bioethanol by fermentation in the presence of the yeasts: S. cerevisiae and S. carlsbergensis. Monitoring of fermentation kinetic parameters such as Brix degree, pH, titratable acidity and density, shows a great variability of these parameters during the fermentation process in bioreactors. The distillation of the musts at the end of fermentation made it possible to obtain ethanol levels (% v/v at 20 °C) between (2.77 ± 0.03%) and (28.69 ± 0.03%). The best ethanolic bioconversion performance was recorded with the yeast S. carlsbergensis on the must enriched with urea (CON2H4) followed by the strain (S3) of the yeast S. cerevisiae. Analysis of the results shows that the alcoholic degrees of the different distillates depend on the type of microorganism as well as whether or not growth factor added to the fermentation musts. It appears that the addition of a selected strain especially in the presence of growth factor promotes the kinetics of the alcoholic fermentation process, thus leading to a better yield of ethanol production. Production of ethanol from agricultural and biodegradable waste would also provide a viable solution to environmental problems creating a sink for waste and renewable energy production as well.
Abstract: In pineapple industries and processing units, peelings constitute waste piled up in landfills and therefore cause real problems for environment. The present study aims to develop this available and neglected bioresource, through the study of the kinetics of its conversion into bioethanol by fermentation with a view to its use as a biofuel. To do th...
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Green Synthesis of Iron Oxide Nanoparticles Using Grapefruit Peel Extract: Application for Removal of Indigo Carmine Dye from Industrial Wastewater
N’guessan Louis Berenger Kouassi,
Donourou Diabate,
Lemeyonouin Aliou Guillaume Pohan,
Benjamin Diby Ossonon,
Luc Dou Blonde,
Albert Trokourey
Issue:
Volume 11, Issue 4, December 2022
Pages:
110-119
Received:
15 October 2022
Accepted:
10 November 2022
Published:
29 November 2022
DOI:
10.11648/j.ajpc.20221104.14
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Abstract: Synthesis of iron oxide nanoparticles by green approach is extremely promising because of its non-toxicity and environmentally friendly behavior. However, few studies have been done on the synthesis of iron oxide nanoparticles using grapefruit peel extract. The aim of the present study was to remove indigo carmine dye from industrial effluent using iron oxide nanoparticles synthesized via grapefruit peel extract. The green iron oxide nanoparticles were characterized by SEM, FTIR, and XRD techniques. The antioxidant activity of green iron oxide was also determined. Batch adsorption experiments were used to investigate the adsorption capacities of indigo carmine by iron oxide nanoparticles in synthetic solutions and industrial effluent. The results showed that the synthesized γ-Fe2O3 surface is coated with grapefruit peel extract. The green γ-Fe2O3 nanoparticles were semi-spherical with an average crystallite size of 11.9 nm, and showed antioxidant activity against DPPH. In the synthetic aqueous solution, the optimum pH value was 2.4 with an indigo carmine adsorption percentage of 84.72%. The kinetic study showed that indigo carmine adsorption by γ-Fe2O3 followed the second-order model and the adsorption process is governed both by external surface adsorption and intra-particle diffusion. Moreover, indigo carmine adsorption by γ-Fe2O3 was well fitted by the Langmuir model. The maximum adsorption percentage in an aqueous solution was 96%. The investigation with industrial effluent indicated that the adsorption percentage of indigo carmine was 28.68%. Therefore, γ-Fe2O3 nanoparticles from grapefruit peel extract may be proposed to purify industrial effluents contaminated by indigo carmine.
Abstract: Synthesis of iron oxide nanoparticles by green approach is extremely promising because of its non-toxicity and environmentally friendly behavior. However, few studies have been done on the synthesis of iron oxide nanoparticles using grapefruit peel extract. The aim of the present study was to remove indigo carmine dye from industrial effluent using...
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A Smoking Gun Scenario Relative to Fluid Dynamics in Closed Conduits
Issue:
Volume 11, Issue 4, December 2022
Pages:
120-127
Received:
9 November 2022
Accepted:
24 November 2022
Published:
30 November 2022
DOI:
10.11648/j.ajpc.20221104.15
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Abstract: Recent scientific articles published by many of the most popular authors in HPLC, based both in Academia, as well as at industry leading companies, regarding the relatively new technology in chromatography known as UHPLC, have increasingly focused on a methodology of evaluating the performance of packed chromatographic columns, by suggesting that the value of the Kozeny constant is variable, rather than a constant. This practice is totally invalid and, in addition, is demonstrably false. In this paper, we will prove, conclusively, that this is the case. In so doing, we will use the experimental data provided by these very authors themselves, in combination with well – settled fluid dynamics theory dating back to 1901, to prove that their conclusions relative to their calculated values for the Kozeny constant, are entirely without merit and not supported by their own measurements. In addition, we will further demonstrate that, based upon a newly minted theory of fluid dynamics in closed conduits, published for the first time in 2019, representing the most recently published reference in fluid dynamics, the unique constant value for this Kozeny parameter, which has been previously shown to be validated over the entire fluid flow regime, will be identified and applied to the reported data, thus, correcting for the errors made by the paper authors and ending approximately 150 years of ambiguity in the science of packed conduits and, HPLC, in particular.
Abstract: Recent scientific articles published by many of the most popular authors in HPLC, based both in Academia, as well as at industry leading companies, regarding the relatively new technology in chromatography known as UHPLC, have increasingly focused on a methodology of evaluating the performance of packed chromatographic columns, by suggesting that t...
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Sources and Distribution of Mercury (Hg) Residues in Sediments and Physico-Chemical Characterization of Waters in the Cotonou Channel and Lake Nokoué, Benin
Alassane Youssao Abdou Karim,
Etiennette Dassi,
Finagnon Gabin Laly,
Gildas Fiacre Agossou,
Djafarou Abdoulaye,
Sylvain Zoffoun,
Martin Aina,
Daouda Mama
Issue:
Volume 11, Issue 4, December 2022
Pages:
128-138
Received:
13 November 2022
Accepted:
28 November 2022
Published:
8 December 2022
DOI:
10.11648/j.ajpc.20221104.16
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Abstract: Water is an essential resource for maintaining aquatic life and the quality of aquatic products. However, sediments are the most important place of accumulation of metal residues and their remobilization in the food chain. The objective of this work is to study the water physicochemical quality and the mercury contamination levels of the sediments in the Channel of Cotonou and Lac Nokoué. Temperature, pH, conductivity, salinity and dissolved oxygen have been measured on-situ in surface and deep water. The surface sediments have been sampled and analyzed in the laboratory using the cold vapor technique (CV-AAS) by the Direct Mercury Analyzer (DMA 80) for mercury analysis. The characterization of the sediments through the granulometric fractions shows that the channel is sandy due to marine inputs while Lake Nokoué is essentially of the silt-sandy type. Mercury concentrations in Lake Nokoué sediments (up to 130.72 µg/kg) greatly exceed geochemical natural loads (20-30 µg/kg) and reveal mercury contamination; this is the case along the channel where the distribution of these residues is very uneven due to the dilution observed at the mouth by marine inputs from the Atlantic Ocean. According to the results obtained, the sediments of the two ecosystems are of class 6, extremely polluted sediments (Igeo > 5) showing a significant risk of migration of these residues in the food chain, especially for benthic organisms.
Abstract: Water is an essential resource for maintaining aquatic life and the quality of aquatic products. However, sediments are the most important place of accumulation of metal residues and their remobilization in the food chain. The objective of this work is to study the water physicochemical quality and the mercury contamination levels of the sediments ...
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