In most developing countries, particularly in the countries of sub-Saharan Africa, corn cobs are considered as waste polluting the environment during the harvest period of this cereal. In order to valorize this agricu...In most developing countries, particularly in the countries of sub-Saharan Africa, corn cobs are considered as waste polluting the environment during the harvest period of this cereal. In order to valorize this agricultural waste, high-performance, inexpensive and low-energy consumption magnetic bioadsorbents were prepared from corn cobs. The chemically activated raw corn cob was magnetized by coating the surface with magnetite nanoparticles. The prepared biosorbents were characterized by FT-IR, XRD, FE-SEM associated with EDX, HR-TEM, TG analysis, BET surface area analysis and XPS. The maximum specific surface area of 35.22 m<sup>2</sup>/g was reached. An attempt to use of these magnetic biosorbents for the removal of heavy metal like Cr(VI) from aqueous solution was envisaged.展开更多
Phosphorus is introduced into the aquatic environment from different point sources, mainly by domestic and industrial wastewater;contributing to the <span>eutrophication of water bodies. </span><span st...Phosphorus is introduced into the aquatic environment from different point sources, mainly by domestic and industrial wastewater;contributing to the <span>eutrophication of water bodies. </span><span style="font-family:;" "="">The most common way for wastewater dephosphation is the injection of expensive chemicals into these bodies of water</span><span style="font-family:;" "="">. Thus, the main objective of this work</span><span style="font-family:;" "=""> </span><span style="font-family:;" "="">was to find an alternative to chemicals by using clay materials from C<span style="color:#4F4F4F;font-family:-apple-system, "font-size:16px;white-space:normal;background-color:#F7F7F7;">ô</span>te d’Ivoire to adsorb phosphate</span><span style="font-family:;" "=""> ions from aqueous solutions. The clay samples, taken from various regions were characterized by X-ray diffraction. They have a different mineralogical composition. The influence of various parameters such as the pH of the medium, contact time, the ion force, temperature, etc. on the adsorption was studied. Adsorption is influenced by the temperature, the pH of the medium, valence of the saturated cation and the clay composition. It is described by a kinetic model of the pseudo-second order. </span><span style="font-family:;" "="">The salt of the medium has no significant effect on the process</span><span style="font-family:;" "="">. The thermodynamic study revealed that adsorption is spontaneous, endothermic and that it is done by electrostatic means of physical nature.</span>展开更多
This study aims to assess the physico-chemical quality of irrigation water and soil in the irrigated area of M’Bahiakro. Seasonal campaigns to measure in situ the physical parameters (pH, temperature, salinity, elect...This study aims to assess the physico-chemical quality of irrigation water and soil in the irrigated area of M’Bahiakro. Seasonal campaigns to measure in situ the physical parameters (pH, temperature, salinity, electrical conductivity and total dissolved solids) of the N’Zi River were carried out, followed by sampling (water and soil) for chemical analyses. The physico-chemical quality of irrigation water was assessed on the basis of four (4) parameters, namely Dry Residue (SR), Osmotic Pressure (π), Kelly Coefficient (KCR), Sodium Absorption Rate (SAR) and Wilcox Diagram. In terms of soil quality, the parameters (pH, N, P, P, K, MO, CEC and ESP) were determined. Overall, the results show a good physical-chemical quality of the irrigation water and soil. Indeed, the irrigation waters studied show good physico-chemistry and low to medium salinity depending on the seasons of the year. As for the soils, they have a clayey-silt texture, a slightly acidic pH, favourable to rice cultivation and a good organic matter content, which best maintains an active microbial life. In addition, the major elements (nitrogen, phosphorus and potassium) present in irrigation water and soils could be enough to optimize the yield of rice cultivation. These results then lead to the conclusion that the irrigation water from the N’Zi River and the soils of the irrigated perimeter of M’Bahiakro are naturally suitable for agricultural use, particularly for rice cultivation. As a result, an additional supply of fertilizer (NPK) would not necessarily be necessary during the exploitation phase of the rice area.展开更多
A systematic study was carried out to assess the level of contamination with fluorides and heavy metals in the drinking water of the city of Daloa as well as the risks to the health of consumers. The waters of 11.11% ...A systematic study was carried out to assess the level of contamination with fluorides and heavy metals in the drinking water of the city of Daloa as well as the risks to the health of consumers. The waters of 11.11% of the sites sampled exceeded the fluoride limit for drinking water with a contamination index (CI) greater than 0. All the waters recorded concentrations of cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn) and lead (Pb) above the recommended values with CI > 0. However, 22.22% of the sites recorded concentrations below the standard for zinc (Zn) with IC < 0. The assessment of adverse effects on human health showed that the chronic daily intake (CDI) of fluorine and metals was less than 1 (CDI < 1) for both adults and children except for Zn where the CDI > 1 for children in 22.22% of drinking water studied. HQs have an average of less than 1 for fluorine and greater than 1 for all metals. Moreover, the danger indices have values greater than 1. The incremental lifetime cancer risk (ILCR) and the total ILCR are above the recommended values. These results showed that the drinking water sampled is of poor quality due to higher levels of heavy metals, which can constitute a danger to human health. Long-term use of one of these poor quality waters can lead to cancer in consumers. It is therefore necessary to treat this water in order to eliminate the metals before using it for drinking. This study can help decision-makers and competent authorities in charge of water management.展开更多
Due to acidic solutions aggressiveness, corrosion inhibitors use is considered to be one the most practical methods to delay metals dissolution in the said solutions. In this study benzimidazolyl derivative namely 2-c...Due to acidic solutions aggressiveness, corrosion inhibitors use is considered to be one the most practical methods to delay metals dissolution in the said solutions. In this study benzimidazolyl derivative namely 2-cyanochalcones 2-(5-nitro-1,3-dihydrobenzimidazol-2-ylidene)-3-oxo-3-(2-oxo-2H-chromen-3-yl) propanenitrile which was synthesized was then applied as a corrosion inhibitor for copper in 1 M HNO<sub>3</sub> solution. The inhibition action of this molecule was evaluated by gravimetric and density functional theory (DFT) methods. It was found experimentally that this compound has a better inhibition performance and its adsorption on copper surface follows Langmuir adsorption isotherm. This adsorption evolves with temperature and inhibitor concentration, it is endothermic and occurs spontaneously with an increase in disorder. Corrosion kinetic parameters analysis supported by Adejo-Ekwenchi model revealed the existence of both physisorption and chemisorption. DFT calculations related that compound adsorption on copper surface is due to its electron donating and accepting capacity. The reactive regions specifying the electrophilic and nucleophilic attack sites were analyzed using Fukui and dual descriptor functions. Experimental results obtained were compared with the theoretical findings.展开更多
The Davo River, an affluent of the Sassandra River, like other rivers in Côte d’Ivoire, is subject to anthropogenic activities likely to deteriorate its quality which could affect its use as drinking water ...The Davo River, an affluent of the Sassandra River, like other rivers in Côte d’Ivoire, is subject to anthropogenic activities likely to deteriorate its quality which could affect its use as drinking water and also the health of aquatic organisms. This study aims at monitoring the temporal evolution of the physico-chemical quality of the waters of the Davo River at the Dakpadou hydrometric station. Twelve monthly field missions were carried out to sample water, measure temperature, pH, Electrical Conductivity and analyse turbidity, Suspended solids, major elements (Cl<sup>-</sup>, NO<sub>3</sub><sup>-</sup>,HCO<sub>3</sub><sup>-</sup>, SO<sub>4</sub><sup>2</sup><sup>-</sup><sup></sup>, Mg<sup>2+</sup>, Ca<sup>2+</sup>, Na<sup>+</sup>, and K<sup>+</sup>) and Trace Metallic Elements (Hg, Fe, Cu, Cr, and Pb). Results show that the waters of the Davo river are poorly mineralized. They are also acidic during periods of low water and slightly basic during flooding periods. The average turbidity value of 10.18 NTU places these waters in the slightly turbid class. The waters have calcic bicarbonate facies during low water periods and sodium bicarbonate facies with low concentrations of major elements during flood months. The average TME concentrations of the Davo river indicate that the waters are not harmful for the health of the population and the aquatic environment.展开更多
This paper describes the evaluation of trace element composition of atmospheric aerosol particles (PM<sub>2.5</sub> and PM<sub>10</sub>) and their influence on air quality in the largest indust...This paper describes the evaluation of trace element composition of atmospheric aerosol particles (PM<sub>2.5</sub> and PM<sub>10</sub>) and their influence on air quality in the largest industrial area of Abidjan city, C?te d’Ivoire. Multi-week sampling was conducted in an urban site (industrial area) in Abidjan from April 2018 to July 2019. The mean mass concentration was 48.83 ± 15.24 μg/m<sup>3</sup> for PM<sub>2.5</sub> and 77.34 ± 10.91 μg/m<sup>3</sup> for PM<sub>10</sub>, with significant temporal variability. The average ratio of PM<sub>2.5</sub>/PM<sub>10</sub> was 0.64 ± 0.21. The concentration of BC in PM<sub>2.5</sub> and PM<sub>10</sub> was respectively 52.32 ± 7.48 μg/m<sup>3</sup> and 52.26 ± 12.07 μg/m<sup>3</sup>. Twenty-two elements: Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Zr and Pb were analysed by Energy Dispersive X-ray Fluorescence (EDXRF). Elemental composition data were modeled using principal component analysis (PCA) with varimax rotation to determine two (2) and four (4) dominant source categories contributing to PM<sub>2.5</sub> and PM<sub>10</sub> respectively. In the case of fine particles PM<sub>2.5</sub>, the possible sources were Industrial activities and non-exhaust emissions, exhaust emissions. The PM<sub>10</sub> sources were industrial activities and non-exhaust emissions, industrial processes, mineral dust, and waste combustion.展开更多
文摘In most developing countries, particularly in the countries of sub-Saharan Africa, corn cobs are considered as waste polluting the environment during the harvest period of this cereal. In order to valorize this agricultural waste, high-performance, inexpensive and low-energy consumption magnetic bioadsorbents were prepared from corn cobs. The chemically activated raw corn cob was magnetized by coating the surface with magnetite nanoparticles. The prepared biosorbents were characterized by FT-IR, XRD, FE-SEM associated with EDX, HR-TEM, TG analysis, BET surface area analysis and XPS. The maximum specific surface area of 35.22 m<sup>2</sup>/g was reached. An attempt to use of these magnetic biosorbents for the removal of heavy metal like Cr(VI) from aqueous solution was envisaged.
文摘Phosphorus is introduced into the aquatic environment from different point sources, mainly by domestic and industrial wastewater;contributing to the <span>eutrophication of water bodies. </span><span style="font-family:;" "="">The most common way for wastewater dephosphation is the injection of expensive chemicals into these bodies of water</span><span style="font-family:;" "="">. Thus, the main objective of this work</span><span style="font-family:;" "=""> </span><span style="font-family:;" "="">was to find an alternative to chemicals by using clay materials from C<span style="color:#4F4F4F;font-family:-apple-system, "font-size:16px;white-space:normal;background-color:#F7F7F7;">ô</span>te d’Ivoire to adsorb phosphate</span><span style="font-family:;" "=""> ions from aqueous solutions. The clay samples, taken from various regions were characterized by X-ray diffraction. They have a different mineralogical composition. The influence of various parameters such as the pH of the medium, contact time, the ion force, temperature, etc. on the adsorption was studied. Adsorption is influenced by the temperature, the pH of the medium, valence of the saturated cation and the clay composition. It is described by a kinetic model of the pseudo-second order. </span><span style="font-family:;" "="">The salt of the medium has no significant effect on the process</span><span style="font-family:;" "="">. The thermodynamic study revealed that adsorption is spontaneous, endothermic and that it is done by electrostatic means of physical nature.</span>
文摘This study aims to assess the physico-chemical quality of irrigation water and soil in the irrigated area of M’Bahiakro. Seasonal campaigns to measure in situ the physical parameters (pH, temperature, salinity, electrical conductivity and total dissolved solids) of the N’Zi River were carried out, followed by sampling (water and soil) for chemical analyses. The physico-chemical quality of irrigation water was assessed on the basis of four (4) parameters, namely Dry Residue (SR), Osmotic Pressure (π), Kelly Coefficient (KCR), Sodium Absorption Rate (SAR) and Wilcox Diagram. In terms of soil quality, the parameters (pH, N, P, P, K, MO, CEC and ESP) were determined. Overall, the results show a good physical-chemical quality of the irrigation water and soil. Indeed, the irrigation waters studied show good physico-chemistry and low to medium salinity depending on the seasons of the year. As for the soils, they have a clayey-silt texture, a slightly acidic pH, favourable to rice cultivation and a good organic matter content, which best maintains an active microbial life. In addition, the major elements (nitrogen, phosphorus and potassium) present in irrigation water and soils could be enough to optimize the yield of rice cultivation. These results then lead to the conclusion that the irrigation water from the N’Zi River and the soils of the irrigated perimeter of M’Bahiakro are naturally suitable for agricultural use, particularly for rice cultivation. As a result, an additional supply of fertilizer (NPK) would not necessarily be necessary during the exploitation phase of the rice area.
文摘A systematic study was carried out to assess the level of contamination with fluorides and heavy metals in the drinking water of the city of Daloa as well as the risks to the health of consumers. The waters of 11.11% of the sites sampled exceeded the fluoride limit for drinking water with a contamination index (CI) greater than 0. All the waters recorded concentrations of cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn) and lead (Pb) above the recommended values with CI > 0. However, 22.22% of the sites recorded concentrations below the standard for zinc (Zn) with IC < 0. The assessment of adverse effects on human health showed that the chronic daily intake (CDI) of fluorine and metals was less than 1 (CDI < 1) for both adults and children except for Zn where the CDI > 1 for children in 22.22% of drinking water studied. HQs have an average of less than 1 for fluorine and greater than 1 for all metals. Moreover, the danger indices have values greater than 1. The incremental lifetime cancer risk (ILCR) and the total ILCR are above the recommended values. These results showed that the drinking water sampled is of poor quality due to higher levels of heavy metals, which can constitute a danger to human health. Long-term use of one of these poor quality waters can lead to cancer in consumers. It is therefore necessary to treat this water in order to eliminate the metals before using it for drinking. This study can help decision-makers and competent authorities in charge of water management.
文摘Due to acidic solutions aggressiveness, corrosion inhibitors use is considered to be one the most practical methods to delay metals dissolution in the said solutions. In this study benzimidazolyl derivative namely 2-cyanochalcones 2-(5-nitro-1,3-dihydrobenzimidazol-2-ylidene)-3-oxo-3-(2-oxo-2H-chromen-3-yl) propanenitrile which was synthesized was then applied as a corrosion inhibitor for copper in 1 M HNO<sub>3</sub> solution. The inhibition action of this molecule was evaluated by gravimetric and density functional theory (DFT) methods. It was found experimentally that this compound has a better inhibition performance and its adsorption on copper surface follows Langmuir adsorption isotherm. This adsorption evolves with temperature and inhibitor concentration, it is endothermic and occurs spontaneously with an increase in disorder. Corrosion kinetic parameters analysis supported by Adejo-Ekwenchi model revealed the existence of both physisorption and chemisorption. DFT calculations related that compound adsorption on copper surface is due to its electron donating and accepting capacity. The reactive regions specifying the electrophilic and nucleophilic attack sites were analyzed using Fukui and dual descriptor functions. Experimental results obtained were compared with the theoretical findings.
文摘The Davo River, an affluent of the Sassandra River, like other rivers in Côte d’Ivoire, is subject to anthropogenic activities likely to deteriorate its quality which could affect its use as drinking water and also the health of aquatic organisms. This study aims at monitoring the temporal evolution of the physico-chemical quality of the waters of the Davo River at the Dakpadou hydrometric station. Twelve monthly field missions were carried out to sample water, measure temperature, pH, Electrical Conductivity and analyse turbidity, Suspended solids, major elements (Cl<sup>-</sup>, NO<sub>3</sub><sup>-</sup>,HCO<sub>3</sub><sup>-</sup>, SO<sub>4</sub><sup>2</sup><sup>-</sup><sup></sup>, Mg<sup>2+</sup>, Ca<sup>2+</sup>, Na<sup>+</sup>, and K<sup>+</sup>) and Trace Metallic Elements (Hg, Fe, Cu, Cr, and Pb). Results show that the waters of the Davo river are poorly mineralized. They are also acidic during periods of low water and slightly basic during flooding periods. The average turbidity value of 10.18 NTU places these waters in the slightly turbid class. The waters have calcic bicarbonate facies during low water periods and sodium bicarbonate facies with low concentrations of major elements during flood months. The average TME concentrations of the Davo river indicate that the waters are not harmful for the health of the population and the aquatic environment.
文摘This paper describes the evaluation of trace element composition of atmospheric aerosol particles (PM<sub>2.5</sub> and PM<sub>10</sub>) and their influence on air quality in the largest industrial area of Abidjan city, C?te d’Ivoire. Multi-week sampling was conducted in an urban site (industrial area) in Abidjan from April 2018 to July 2019. The mean mass concentration was 48.83 ± 15.24 μg/m<sup>3</sup> for PM<sub>2.5</sub> and 77.34 ± 10.91 μg/m<sup>3</sup> for PM<sub>10</sub>, with significant temporal variability. The average ratio of PM<sub>2.5</sub>/PM<sub>10</sub> was 0.64 ± 0.21. The concentration of BC in PM<sub>2.5</sub> and PM<sub>10</sub> was respectively 52.32 ± 7.48 μg/m<sup>3</sup> and 52.26 ± 12.07 μg/m<sup>3</sup>. Twenty-two elements: Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Zr and Pb were analysed by Energy Dispersive X-ray Fluorescence (EDXRF). Elemental composition data were modeled using principal component analysis (PCA) with varimax rotation to determine two (2) and four (4) dominant source categories contributing to PM<sub>2.5</sub> and PM<sub>10</sub> respectively. In the case of fine particles PM<sub>2.5</sub>, the possible sources were Industrial activities and non-exhaust emissions, exhaust emissions. The PM<sub>10</sub> sources were industrial activities and non-exhaust emissions, industrial processes, mineral dust, and waste combustion.
