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Study of the Adsorption Efficacy of Cr(III) on a Metal Oxide-Based Material Derived from the Quartz Sand Enrichment Process
Alma Shehu,
Majlinda Vasjari,
Sonila Duka,
Loreta Vallja,
Nevila Broli
Issue:
Volume 12, Issue 3, June 2023
Pages:
58-65
Received:
5 November 2022
Accepted:
23 February 2023
Published:
18 May 2023
Abstract: In the present study, the efficacy of chromium removal from water media was studied. For this purpose, a metal oxide based material, derived from the enrichment process of quartz coastal sand was used as possible adsorbent of chromium (III) ions. Following additional modification of the adsorbent, the effect of operational parameters including pH, contact time and Cr(III) concentration were studied according to one-factor-at-a-time procedure. Adsorption efficacy was assessed by the measurement of the remaining chromium concentration in solution, after adsorption. Atomic absorption spectroscopy technique, with flame atomization was used for the determination of chromium concentration in solution. Obtained results revealed that selected material exhibited higher adsorption efficacy in alkaline solution (pH = 6-9). The maximum removal efficacy (>93%) was achieved after 180 minutes of contact time, with an adsorbent dosage of 5 g/L and initial chromium concentration 20 mg/L. The adsorption process for Cr(III) follow the Freundlich isotherm and gives high correlation coefficient R2. Calculations performed based on the Langmuir isotherm showed that the maximum adsorption efficiency of Cr3+ in the natural metal-oxide material has resulted 10 mg/g or 10000 μg/g. Pseudo second order reaction kinetics has provided a realistic description for removal of Cr(III) from solution with high correlation coefficient R2 of (0.999). The adsorption isotherms were better described by the Freundlich equation (R2 = 0.934). Adsorption of trivalent chromium ions onto selected material followed the pseudo second order model (R2 = 0.996). Hence, the residual materials derived from the enrichment processes of quartz sand can be used as alternative adsorbent for the removal of trivalent chromium ions from aqueous solutions.
Abstract: In the present study, the efficacy of chromium removal from water media was studied. For this purpose, a metal oxide based material, derived from the enrichment process of quartz coastal sand was used as possible adsorbent of chromium (III) ions. Following additional modification of the adsorbent, the effect of operational parameters including pH, ...
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Contribution to the Assessment of the Impact of Mining Activities on Water Resources and Sediments in the Ubangi Basin: Case of the Moboma Commune (Bagandou)
Herbert Nam-Sionou Remademo,
Eric Foto,
Oscar Allahdin,
José Kpeou,
Gildas Doyemet,
Narcisse Zoudamba,
Bruno Nguerekossi,
Cyrille Ndepete
Issue:
Volume 12, Issue 3, June 2023
Pages:
66-77
Received:
2 January 2023
Accepted:
15 May 2023
Published:
29 May 2023
Abstract: Recently, the problems posed by chemical contaminants, in particular metallic trace elements (TMEs), in the environment, have aroused the interest of the scientific community, because the protection of the environment requires knowledge of the fate of these contaminants and their effects on the living beings that depend on them. Their presence in environmental matrices is often caused by human activities, particularly agriculture, livestock farming, industry and transport. In the region of the Lobaye prefecture, in the south-west of the Central African Republic, gold and diamonds have been mined for decades in an artisanal manner using inadequate methods and environmentally unfriendly substances such as mercury and cyanide. The aim of this study is to determine the trace metal content of the water and sediments in the study area in order to predict the environmental and health risks associated with their use. Water and sediment samples were taken at 16 sites, 6 boreholes, 10 watercourses and a control well, and their concentrations in metals such as Cd, Cu, Hg, Ni, Pb and Zn were analysed by inductively coupled plasma mass spectrometry (ICP-MS). The results obtained reveal a significant contamination of these waters and underline a significant variability of the concentrations of the TMEs according to the metal analysed and the type of water, on the semi-mechanised exploitation site at DIKEKELE, the concentration of mercury is 8 µg/l higher than the standard of 1 µg/. The sediments are composed of a majority of Quartz at about 80% on average and 20% overall of kaolinite and muscovite and contain a high proportion of Cr, Pb, Cu, Co and Ni and a low proportion of Hg.
Abstract: Recently, the problems posed by chemical contaminants, in particular metallic trace elements (TMEs), in the environment, have aroused the interest of the scientific community, because the protection of the environment requires knowledge of the fate of these contaminants and their effects on the living beings that depend on them. Their presence in e...
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Fast Growing Energy Forest - Is "The Fifth Element" That Humanity Lacks for a 100% Changing to Clean Renewable Energy
Issue:
Volume 12, Issue 3, June 2023
Pages:
78-84
Received:
5 April 2023
Accepted:
30 May 2023
Published:
9 June 2023
Abstract: Renewable and clean energy sources are the only way for humanity to live harmoniously on planet Earth. How to achieve this goal? Solar and wind energy are produced only when the sun and wind are present. The percentage of hydropower is quite small. Therefore, compensating sources of energy are needed at night and in winter. Today, these are coal and gas-fired power plants. The goal of the Fast grow Energy Forest project is to grow and harvest wood (biomass) as a source of replacing fossil coal and gas for power plants and boilers. Ten-year research by scientists together with producers demonstrates the effectiveness of growing fast-growing trees, which are technologically cut with harvesters for biomass every 3 years. This project has great economic, environmental and energy prospects and needs immediate support from financial institutions, scientists and the government. This is a real ecologically clean bioaccumulator of solar energy. After the complete cutting of plants, willow plantations, the shoots grow again and after three years the upper part of the tree is completely restored. That is, when cutting Fast grow Energy Forest for wood, we do not destroy it, but restore it. Is this project environmentally friendly? After all, we burn sawn wood and pollute the air with CO2? Yes, this project is ecological and works with "zero" use of CO2 and even additionally cleans the air. In Figure 1 of CO2 absorption, we see the complete cycle of carbon movement. Every three years, the plantation absorbs about 200 tons of CO2 from the air. During combustion, 70% of CO2, 140 tons, is released into the air, and 60 tons, which is 30%, remains in the roots. This process is repeated every 3 years and involves 8 or more biomass harvests. Europe's potential of 117 million hectares of marginal land (land unsuitable for agriculture) and 5.5 million kilometers of roads is also the potential for FgEF creation. In conversion, this amounts to 82.6 billion m3 of gas equivalent. We are also reducing CO2 emissions by 3.17 billion tons.
Abstract: Renewable and clean energy sources are the only way for humanity to live harmoniously on planet Earth. How to achieve this goal? Solar and wind energy are produced only when the sun and wind are present. The percentage of hydropower is quite small. Therefore, compensating sources of energy are needed at night and in winter. Today, these are coal an...
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