In order to protect and improve market garden crops, market gardeners use large quantities of plant protection products and water in the production area. This has an impact on soil quality. The aim of this study was to determine the level of soil pollution downstream of the Daloa Regional Hospital. Twenty-four soil samples were taken from six sites in the study area. These samples were analysed by liquid/liquid chromatography coupled with mass spectrophotometry. The results of the analyses revealed the presence of seven medicinal residues, including five antibiotics (Ciprofloxacin, Erythromycin, Tetracycline, Sulfamethoxazole and Norfloxacin), a beta-blocker (Propranolol) and an anti-inflammatory (Salicylic Acid). The average concentrations of these antibiotic residues ranged from 3.41 to 50.34 µg/kg; the anti-inflammatory and the beta-blocker recorded values of 112.67 µg/kg and 17.35 µg/kg respectively. Eleven residues of active ingredients, including Chlorothalonil, Cypermethrin, Metamidophos, Endrin, Deltamethrin, Dimethomorph, Profenofos, Beta-endosulfan, Etoenprox, Furathiocarb and Carbendazim, were quantified at levels ranging from 0.04 to 39.62 µg/kg. These active ingredients belong to five families of plant protection products: organochlorines, organophosphates, carbamates, thiocarbamates and synthetic pyrethroids. The constant discharge of these medicinal and phytosanitary residues contaminates the soil and poses a threat to humans and their environment.

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.

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.

Adsorption of heavy metals on activated carbons is influenced by various factors that must be controlled. This study investigates the optimal conditions for removal lead on activated carbon using experimental designs. Thus influence of three parameters (pH, lead concentration and activated carbon) on adsorption rate was studied. Activated carbons was prepared from coconuts shells of Côte d’Ivoire by using chemical activation method. PH, lead concentration and coal nature are the factors taken into account in the two-level complete factorial plan used for optimization. Values of lead elimination rate are between 87 % and 96 % thus indicating the pertinence of the choice of the experimental domain. Moreover, two of the three factors; pH and lead concentration have a significant influence on the lead removal rate. Also, interactions between carbon type and lead concentration and those between pH and concentration have a significant influence on adsorption. Thus, the optimal adsorption conditions of 50 mL of lead at 150 mg / L of concentration are obtained with 0.3 g of activated carbon, at pH 6 and at a temperature of 25 ° C. Experimental designs therefore make it possible to optimize lead removal conditions from wastewater.

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).

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.