Graphene oxide (GO) was prepared from black carbon by the Hummers method. The prepared GO was characterized by Scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDX), Brunner-Emmett-Teller (BET) surface area analyzer, and Fourier transform infrared spectroscopy (FTIR). Go wasusedfor U(VI) adsorption of Uranium ions from the acid solution. The effects of environmental settings on U(VI) adsorption were studied, including pH, contact time, adsorbent dose, initial concentration of U (VI), and temperature.The experimental results showed that the best uptake of uranium ions on Go adsorbent is 68.0 mg/g at pH 4, and150 mg/L initial U(VI) concentration for 50 min contact time at room temperature.  The kinetic data fitted well with the pseudo-second-order kinetic model.Langmuir's adsorption model described the adsorption isotherm while the adsorption process was non-spontaneous, randomness, and exothermic. Also, the graphene oxide adsorbent was truly regenerated by 0.8M H2SO4 and 1:50 S:L ratio for 60 min contact time.  Seven cycles of adsorption-desorption experiments were conducted to study the practical applicability and recurrent use of graphene oxide as an adsorbent.

Rational and equitable distribution of portable water is one of the major challenges of our time. Numerous programmes and projects aimed at ensuring access to portable water have been initiated in Cameroon in general and Yaounde in particular but the much-desired outcome of “access to all” is more of a theoretical than a practical reality. It is based on this premise that this paper provides a useful lens/windowon the current state of the water distribution network in the city of Yaounde through the use of the Geographical Information Systems (GIS) with a view to provide a wealth of information that will enable decision-makers to have a strategic vision on the priority areas for extension of the portable water network in the city of Yaounde. The methodology consisted of combining a set of tools and approaches such as GIS, multi-criteria analysis, grey data from population density, housing density, alternative water sources and the current water distribution network. The findings have revealed a mismatch/uneven distribution of the water network within the various neighbourhoods under study with a consequent imbalance between supply and demand. Such neighbourhoods with limited pipe borne water, the findings of this paper suggest are, priority areas for extension of the water distribution network in Yaounde. In these neighbourhoods, the populations have implemented coping strategies through the setting up of alternative water sources for their water supplies, which regrettably has a negative impact on health.

In this paper, we shall introduce and study the pairwise connected and pairwise disconnected bitopological spaces and investigates some of their characterizations. Some definitions and examples would be providing in order to establish their properties. Furthermore, the 0-dimensional space and pairwise totally disconnected bitopological spaces are also discussed. Topology is formally a study of topological invariants.