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.