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Conversion of shea butter shell charcoal to briquettes solid fuel is a means to reduce environmental pollution. This study investigated the potential of converting shea butter shell char to briquettes with cassava starch solution. The shell was pretreated and carbonized at temperature of 450 °C for 45 min in a furnace. Five briquette samples were produced with constant weight mass of char and different masses of cassava starch binder was varied as 10 %, 30 %, 50 %, 70 % and 90 %. The briquettes produced were analyzed for moisture content, bulk density, shatter index, water resistance, calorific value and compressive strength. The effect of the different binder contents on quality of the briquette samples was also investigated. The result revealed moisture content varied from 9.12 % to 14.83 % and density varied from 0.61 g cm-3 to 0.85 g cm-3. The water resistance of the briquettes increased from 40.7 % to 75.5 % and shatter index increased from 71.7 % to 92.1 %., while compressive strength values ranged from 18.63 MPa to 24.46 MPa. The calorific values of the briquettes in their increasing amount of binder were found to be between 16.94 and 22.33 MJ/kg. The briquette with the highest amount of binder had compressive strength of 24.46 MPa and calorific value of 22.33 MJ/kg. The results showed the conversion of sheabutter shell to briquette can serve as an effective technique to bringing value and use to biomass wastes. [ABSTRACT FROM AUTHOR]

The present study indicates that Ahoko kaolinite clay is an effective adsorbent for the uptake of both Cu (II) and Cr (VI) ions from wastewater. The adsorption process is studied with variation of time, temperature and adsorbent dosage at an effluent pH of 6. X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), Brunauer Emmett and Teller (BET) and Scanning electron microscopy (SEM) are used to characterize the adsorbents. The XRD spectra show that the modification with KH2PO4 does not significantly change the crystal spacing of the clay mineral lattice structure; however, there are shifts in the intensity of the peaks for the modified kaolinite clay. The FTIR spectra show that certain functional groups are responsible for binding the metal ions from the solution. The SEM analysis indicates an increase of the porosity of the modified adsorbent as compared with that of the unmodified one enhancing the metal ion adsorption on the modified kaolinite clay. The BET study indicates that the phosphate modification increases the surface area and the total pore volume of the kaolinite clay. The kinetic study reveals that a pseudo-second order model shows a good fit in case of all reaction times and initial concentrations studied. The mechanism of the sorption process is evaluated using thermodynamic properties such as the enthalpy change (ΔH), the Gibbs free energy change (ΔG), and the entropy change (ΔS). The negative values of the free energy change (ΔG) suggest spontaneity and feasibility of the process. The positive values of the enthalpy change (ΔH) indicate an endothermic nature of the process. It is also noted that the Ahoko kaolinite clay has a higher affinity for adsorption of Cu (II) ions than that of Cr (VI) ions. [ABSTRACT FROM AUTHOR]