Nangui Abrogoua University, Department of Sciences and Environmental Management, Laboratory of Environmental Sciences, 02 BP 801 Abidjan 02, Cote d’Ivoire
Coconut shells have been used as a precursor for the preparation of activated carbon by the chemical activation method. The full factorial design was applied to determine the optimum conditions for preparing the activated carbon. The factors studied were the carbonization temperature, the carbonization time and the concentration of the activating agent. Phosphoric acid was the activating agent, used for chemical activation. Planning of the experiments using the three-level full factorial design method resulted in eight trials with the iodine number as the answer to each trial. The various results obtained were analyzed using Nemrow software in order to highlight the influence of factors and their interaction. The results reveal that carbonization temperature, the carbonization time and the concentration exert a significant influence on the iodine number, when they are at their high level, respectively 600 ° C, 4h, 30% for the value of the iodine index of 445.44mg/g.
The preservation and consumption of food of animal origin requires pickling, smoking or cooking techniques. In Côte d'Ivoire, particularly in Abidjan, in the communes of Abobo and Port-Bouët, the stripping of beef hides with fuels such as used tires, rubber debris and rubberwood is a widespread practice. The "kplo" or treated and smoked beef skin is highly prized. The same is true for the "choukouya", beef, sheep or goat meat cooked in artisanal metal ovens fuelled mainly with rubberwood in the communes of Port-Bouët and Yopougon. These practices generate fumes containing entities that are toxic to human food, including trace metal elements (TMEs), which are carcinogenic or mutagenic. The objective of this study is to assess the risks associated with the consumption of meat and offal (skins) contaminated with TMEs. A dietary frequency-based survey was conducted. Sixty (60) skin samples and 120 meat samples were taken. Analysis was performed by atomic absorption spectrophotometry. The results show that rubber wood and used tires are the most commonly used fuels. Among the metals investigated, lead had a daily exposure (6.52 µg/kg bw/d) above its ADI (3.5 µg/kg bw/d). The hazard ratio of 1.86 greater than 1 for lead indicates the occurrence of threshold adverse effects. ERIs greater than 10-5 indicate the occurrence of carcinogenic or mutagenic effects.
This study consisted in optimizing the adsorption capacity of activated carbon from the peanut shell for the removal of the yellow dye 11 (CJ 11) in solution. The active carbons are derived from the peanut shells of the subspecies hypogaea (Arachis hypogaea ssp.hypogaea) of the Virginia type derived from Mankono and subspecies fastigiata (Arachis hypogaea ssp. fastigiata) of the Spanish type from Kani. and Séguela. Peanut shells underwent pyrolysis preceded by chemical impregnation with orthophosphoric acid. The analysis of the results indicates that for the preparation of an optimal activated carbon from the Virginia sub-species hypogaea (Arachis hypogaea ssp. hypogaea) from Kani, an acid concentration of 30% are required and carbonization temperature at 600 ° C for 3 h. This active carbon, which has a predominantly acid surface (92.7% of the total surface area), has an ash content of 3.1%, a degree of activation of 24%, an iodine value of 955.04 mg / g and a surface area of 706.92 m2 / g. The adsorption tests reveal that the Spanish-derived fastigiata (Arachis hypogaea ssp. fastigiata) derived from kani adsorbs the yellow dye better than the other two. And this adsorption capacity increases with the optimal conditions of preparation.