Contamination of the aquatic environment by Metallic Trace Elements (MTE) is a major problem encountered in our environment today. In Côte d’Ivoire, in some municipals, residential and industrial areas in the ci...Contamination of the aquatic environment by Metallic Trace Elements (MTE) is a major problem encountered in our environment today. In Côte d’Ivoire, in some municipals, residential and industrial areas in the city of Abidjan, waste water of worrying quantity is discharged into the rainwater drainage channels which flow directly into the Ebrié lagoon. In order to identify the origin of the pollution by metallic trace elements (MTE) transported by this water, samples of wastewater were collected and then analyzed. ICP-MS was used for MTE (Cu, Fe, Zn, Al, Pb, Cd) analyses and results were statistically processed in multivariate form using PCA and Excel. The results showed high concentrations of metals, with the exception of Cd. The typological structure represents 85.74% of the total information for the MTE. Plan F1 represents 63.90% of the variance and describes water pollution by copper (0.95), zinc (0.90), iron (0.84) and aluminum (0.84). Plan F2 represents 21.84% and describes the enrichment of water with lead (0.84). It seems more than necessary to make manufacturers aware of the need to install wastewater treatment systems in order to avoid their discharge into the environment.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
This study was carried out with a view to appreciate the value of clay, raw materials in eco-construction. To achieve this, we sampled two clay raw materials denoted Aga and Bak and then characterized. The results obt...This study was carried out with a view to appreciate the value of clay, raw materials in eco-construction. To achieve this, we sampled two clay raw materials denoted Aga and Bak and then characterized. The results obtained from geotechnical and mineralogical tests have shown that the clay samples Aga and Bak are fine soils moderately plastic class A soils consisting essentially of quartz with 73.13% and 74.56% respectively for Aga and Bak and clay minerals (kaolinite and illite) with 12.73% kaolinite and 8.55% illite for Aga against 8.31% kaolinite and 13.72% for Bak. Moreover, these samples do not contain swelling clays and contain a sufficient quantity of iron oxides which allows them to be valued in ceramics, in particular in compressed earth bricks (CEB).展开更多
Currently, in a context of sustainable development, the economic and environmental challenges incite, to valorize local materials such as clays and agro-industrial waste. It is in this approach that a new category of ...Currently, in a context of sustainable development, the economic and environmental challenges incite, to valorize local materials such as clays and agro-industrial waste. It is in this approach that a new category of compressed earth bricks (BTC) stabilized with shea meal (TK) and cement was proposed. The purpose of this paper is to investigate the effect of shea meal rate on the thermal conductivity properties of cement stabilized earth bricks. A lateritic clay (Lat) mainly composed of kaolinite (38.44%), quartz (24.94%), goethite (12.28%), hematite (4.44%) and illite (19.9%) was used to make bricks. Different mix designs made up of lateritic clay and 5% cement were studied. The shea meal is added as a partial lateritic clay replacement in different proportions. The thermal conductivity was determined by hot disk method and correlated to both porosity and density of elaborated materials. The results obtained show that the thermal conductivity and density of bricks decrease respectively from 0.72 W·m-1·K-1 to 0.52 W·m-1·K-1 and from 2.77 g·cm-3 to 2.52 g·cm-3. The presence of shea meal within the material generates pore formation, which may partly explain the improvement of the thermal insulation properties. A positive correlation was noted between density and thermal conductivity of these materials.展开更多
This work falls within the general framework of the valorization of the clays of Ivory Coast in order to propose innovative solutions in the resolution of certain problems related to development such as the depollutio...This work falls within the general framework of the valorization of the clays of Ivory Coast in order to propose innovative solutions in the resolution of certain problems related to development such as the depollution of water. Its main objective is therefore to study the physico-chemical properties of two Dabou clays with a view to using them in chemical processes for the treatment of dyeing wastewater. The results of the chemical analysis and the ray diffraction showed that the DAB 1 and DAB 2 samples are clays of the kaolinitic type consisting mainly of kaolinite with 51.17% for DAB 1 against 65.81% for DAB 2 and quartz with respectively 41.76% and 25.8% for DAB 1 and DAB 2. They also contain relatively large amounts of goethite with 9.96% for DAB 1 and 12.8% for DAB 2. The specific surfaces measured in both samples are greater than 25 m<sup>2</sup>/g. All the results of the physico-chemical characterization, in particular the presence in significant quantity of clay minerals, the presence of iron compounds and the large specific surface area of both samples, allow the conclusion that they can be used in adsorption studies and in the heterogeneous Fenton process for water treatment.展开更多
This work was devoted to the study of the physico-chemical properties of two clay minerals from the Mountain District (West Côte d'Ivoire) referenced ME1 and ME2. These samples were characterized by the exper...This work was devoted to the study of the physico-chemical properties of two clay minerals from the Mountain District (West Côte d'Ivoire) referenced ME1 and ME2. These samples were characterized by the experimental techniques, such as X-ray diffraction (XRD), Infrared spectroscopy (IR), Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), Differential Thermal Analysis and Thermogravimetry (DTA-TG), Brunauer, Emett and Teller method (BET), laser particle size analysis and Scanning Electron Microscope (SEM). The main results of these analyses reveal that the two clay samples mainly contain quartz (52.91% for ME1 and 51.72% for ME2), kaolinite (36.60% for ME1 and 41.6% for ME2) and associated phases, namely goethite and hematite (13.47% for ME1 and 11.00% for ME2). The specific surface values obtained for samples ME1 and ME2 are 34.78 m2/g and 29.18 m2/g respectively. The results obtained show that the samples studied belong to the kaolinite family. After calcination, they could have good pozzolanic activity and therefore be used in the manufacture of low-carbon cements.展开更多
文摘Contamination of the aquatic environment by Metallic Trace Elements (MTE) is a major problem encountered in our environment today. In Côte d’Ivoire, in some municipals, residential and industrial areas in the city of Abidjan, waste water of worrying quantity is discharged into the rainwater drainage channels which flow directly into the Ebrié lagoon. In order to identify the origin of the pollution by metallic trace elements (MTE) transported by this water, samples of wastewater were collected and then analyzed. ICP-MS was used for MTE (Cu, Fe, Zn, Al, Pb, Cd) analyses and results were statistically processed in multivariate form using PCA and Excel. The results showed high concentrations of metals, with the exception of Cd. The typological structure represents 85.74% of the total information for the MTE. Plan F1 represents 63.90% of the variance and describes water pollution by copper (0.95), zinc (0.90), iron (0.84) and aluminum (0.84). Plan F2 represents 21.84% and describes the enrichment of water with lead (0.84). It seems more than necessary to make manufacturers aware of the need to install wastewater treatment systems in order to avoid their discharge into the environment.
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This study was carried out with a view to appreciate the value of clay, raw materials in eco-construction. To achieve this, we sampled two clay raw materials denoted Aga and Bak and then characterized. The results obtained from geotechnical and mineralogical tests have shown that the clay samples Aga and Bak are fine soils moderately plastic class A soils consisting essentially of quartz with 73.13% and 74.56% respectively for Aga and Bak and clay minerals (kaolinite and illite) with 12.73% kaolinite and 8.55% illite for Aga against 8.31% kaolinite and 13.72% for Bak. Moreover, these samples do not contain swelling clays and contain a sufficient quantity of iron oxides which allows them to be valued in ceramics, in particular in compressed earth bricks (CEB).
文摘Currently, in a context of sustainable development, the economic and environmental challenges incite, to valorize local materials such as clays and agro-industrial waste. It is in this approach that a new category of compressed earth bricks (BTC) stabilized with shea meal (TK) and cement was proposed. The purpose of this paper is to investigate the effect of shea meal rate on the thermal conductivity properties of cement stabilized earth bricks. A lateritic clay (Lat) mainly composed of kaolinite (38.44%), quartz (24.94%), goethite (12.28%), hematite (4.44%) and illite (19.9%) was used to make bricks. Different mix designs made up of lateritic clay and 5% cement were studied. The shea meal is added as a partial lateritic clay replacement in different proportions. The thermal conductivity was determined by hot disk method and correlated to both porosity and density of elaborated materials. The results obtained show that the thermal conductivity and density of bricks decrease respectively from 0.72 W·m-1·K-1 to 0.52 W·m-1·K-1 and from 2.77 g·cm-3 to 2.52 g·cm-3. The presence of shea meal within the material generates pore formation, which may partly explain the improvement of the thermal insulation properties. A positive correlation was noted between density and thermal conductivity of these materials.
文摘This work falls within the general framework of the valorization of the clays of Ivory Coast in order to propose innovative solutions in the resolution of certain problems related to development such as the depollution of water. Its main objective is therefore to study the physico-chemical properties of two Dabou clays with a view to using them in chemical processes for the treatment of dyeing wastewater. The results of the chemical analysis and the ray diffraction showed that the DAB 1 and DAB 2 samples are clays of the kaolinitic type consisting mainly of kaolinite with 51.17% for DAB 1 against 65.81% for DAB 2 and quartz with respectively 41.76% and 25.8% for DAB 1 and DAB 2. They also contain relatively large amounts of goethite with 9.96% for DAB 1 and 12.8% for DAB 2. The specific surfaces measured in both samples are greater than 25 m<sup>2</sup>/g. All the results of the physico-chemical characterization, in particular the presence in significant quantity of clay minerals, the presence of iron compounds and the large specific surface area of both samples, allow the conclusion that they can be used in adsorption studies and in the heterogeneous Fenton process for water treatment.
文摘This work was devoted to the study of the physico-chemical properties of two clay minerals from the Mountain District (West Côte d'Ivoire) referenced ME1 and ME2. These samples were characterized by the experimental techniques, such as X-ray diffraction (XRD), Infrared spectroscopy (IR), Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), Differential Thermal Analysis and Thermogravimetry (DTA-TG), Brunauer, Emett and Teller method (BET), laser particle size analysis and Scanning Electron Microscope (SEM). The main results of these analyses reveal that the two clay samples mainly contain quartz (52.91% for ME1 and 51.72% for ME2), kaolinite (36.60% for ME1 and 41.6% for ME2) and associated phases, namely goethite and hematite (13.47% for ME1 and 11.00% for ME2). The specific surface values obtained for samples ME1 and ME2 are 34.78 m2/g and 29.18 m2/g respectively. The results obtained show that the samples studied belong to the kaolinite family. After calcination, they could have good pozzolanic activity and therefore be used in the manufacture of low-carbon cements.
