Laboratory Hydrosciences Lavoisier, UNESCO Chair on Water Management, University of Bangui, Faculty of Sciences BP 908 Bangui, Central African Republic
The fragility of Lake Chad’s existence due to climate change and anthropogenic activities has been demonstrated by several scientific articles in physics-chemistry, water chemistry and climatology, as well as studies in the human and social sciences, notably anthropology and sociology. The aim of this study is to investigate the population of the North and North-West of the Central African Republic, the Lake Chad basin, in order to understand all the existing uncertainties which will contribute to the definition of new preventive solutions for the sustainability of water resource management. In human societies, water potential reveals modes of social organization, local socio-political dynamics, power relations and the legitimization of status and social roles. Around water resources, actors with opposing interests confront and clash, making this natural and cultural heritage an «arena» at the heart of social organization. This implies that water potential is one of the «resources most closely interwoven with social and cultural relations», and appears to be a vector of social transformation. This work has highlighted the advent of inter-community conflicts caused by cross-border transhumance, the abandonment of local knowledge on water use, water pollution from mining and the destruction of the ecosystem that protects water resources in the southern slopes of the basin.
The present work focuses on the electrocoagulation treatment of an Evans blue solution (B.E). Of the four bottom salts (KCl, NaCl, Na2SO4, K2SO4) used for the treatment, it appears that, for an optimum charge density of 2.33 F/m3 and a voltage set at 1.5V, potassium chloride (KCl) provides the best abatement rate (95.5%). The variation of the pH of the solution reveals that the best abatement rates are obtained for the basic pH. pH 9 is optimal for treatment whereas for pH values above 10, inefficiency is noted. The speed of the treatment increases with the density of the applied current, the treatment is efficient and the energy cost is limited for a current density value set at 20 mA/ cm2. For the same set values of charge density and voltage, the abatement rate is inversely proportional to the concentration of B.E, and aluminum is better suited as electrode material, compared to iron.