Kouhounina Banzouzi Merline Lady^{1, 2,}, Bibila Mafoumba Jean Claude^{1, 2}, Diamouangana Mpissi Zita Flora³, Ifo Grace Mazel⁴, Moutou Joseph –Marie Saint Bastia³

Industrial development significantly meets the needs of our society. This results in significant releases of pollutants into the environment. Petrochemical and oil refineries are among the industries handling products with the highest polluting capacity. Oil remains the most widely used energy source, particularly for transportation. To meet this demand, crude oil is processed and transformed, the goal being to extract as many high-value products as possible. However, refining processes pose a health risk. Oil refineries produce significant quantities of wastewater during their operations. This wastewater typically contains various types of pollutants, including heavy metals, organic compounds, and other toxic substances. However, oil refineries often have on-site water treatment plants to mitigate the environmental impact of their effluent. These plants use various physical, chemical, and biological processes to remove pollutants from wastewater before it is discharged into waterways or reused elsewhere in the refinery. However, clays have also shown adsorption capacity, degreasing and decolorizing water polluted by industrial discharges. This study is based on this perspective. It reports the adsorption of phenol by local clay materials. Indeed, if it is clearly accepted that Congo has oil; it is also known that the refining process of the latter releases chemicals, in this case phenol. The latter is toxic in the ambient environment and can contaminate surface water, soils and groundwater. The main objective of this study is to enhance the adsorbent properties of local clay materials in the retention of phenol likely to be present in soils and surface waters. To do this, we chose talc from Missafou and kaolinite from Mouyondzi, two localities in the Republic of Congo. The fine fraction is extracted by the method described by Thierry Holtzapffel. Kinetic data showed that phenol was bound after 20 minutes of contact for Mouyondzi kaolinite and 30 minutes for Missafou talc. Batch adsorption tests showed that the adsorption capacity of the clays used was quite high for phenol, and that the Mouyondzi fine fraction adsorbed better than that of Missafou (1.26 mg/g and 1.07 mg/g, respectively), while the adsorption isotherms were more satisfactorily described by the Langmuir model. Both clays were suitable for use as adsorbents for pollution control.

adsorption, phenol, clay, Mouyondzi, Missafou