Effluents from the textile industry and artisanal dyeing contaminate water resources. The objective of this work is to eliminate the dye safranin from the aqueous medium by adsorption on natural materials. The clay used comes from Daloa in the center-west of Côte d’Ivoire. It is ground and then dry sieved on a column of sieves with a diameter of between 45 μm and 2 mm. The balls are made with the diameter fraction between 45 and 125 μm. Thus, 40 mL of distilled water is added to 100 g of clay powder. The balls obtained (approximately 0.5 cm in diameter) are dried in an oven at 60°C for 24 hours, then calcined in the oven at 500°C for 2 hours. The experimental device is a glass column 64.4 cm high and 2.9 cm inside diameter surmounted by a separating funnel containing the solution to be treated. The samples from the adsorption tests are analyzed using an AQUALYTIC 800 brand UV-visible spectrophotometer. Mathematical models are applied to model the breakthrough curves. The results showed that breakthrough time and adsorption capacity increase with bed height (60, 240 and 420 min respectively for 8, 16 and 24 cm) and decrease with flow rate (240, 90 and 30 min respectively). for 2, 3 and 4 mL/min). The modeling of the different breakthrough curves shows that the models applied are able to describe the entire dynamic behavior of the column.

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 study was carried out on tomatoes (Lycopersicon esculentum P. Mill) and cabbages (Brassica oleracea L. var capitata) grown in Daloa. It covered ninety samples of vegetables including 60 tomato samples and 30 samples of cabbage collected during three field campaigns in a locality in Côte d'Ivoire (Daloa). These samples were processed using a SHIMADZU brand liquid chromatograph to determine pesticide residues. The results revealed contamination of tomatoes (Lycopersicon esculentum P. Mill) and cabbages (Brassica oleracea L. var capitata). Four pesticide residues, three of which belong to the organophosphorus family (chlorpyrifos, dimethoate, profenophos) and one from the pyrethroid family, were detected in tomatoes with detection percentages of 39%, 25%, 22% and 14%. The results of the analysis also showed the presence of four other pesticides including two from the organophosphorus family (profenophos and diazinon) and two others from the Carbamate family (carbaryl and dithiocarbamate) in cabbages with a rate of detection of 10% and 27%, 10% and 53% respectively. However, the remaining pesticide levels detected in tomatoes and Daloa cabbages are all below the Codex Alimentarius Standards (MRLs).