Wennd Kouni Igor Ouedraogo

Lipases are essential in many industrial processes. Although microbial lipases are widely used, plant lipases remain more accessible and abundant, particularly in germinated kernels. This study aims to evaluate the catalytic potential of lipase extract powder of germinated rubber kernels in transesterification reaction. Germinated rubber kernels, lipase extract powder of germinated rubber kernels, and crude oils of palm (PKO), Jatropha curcas (JCO), and rubber (RSO) were characterized. The presence of lipase in the plant extract powder was evidenced by FT-IR and SEM-EDX analyses and hydrolysis reaction. Biodiesel was produced from crude rubber oil. The results showed that germinated rubber kernels have high moisture (33.48%), protein (15.75%), and fat (50.11%) contents. The optimum hydrolytic activities of lipase on PKO, JCO, and RSO were 25.67 U/mL, 26.67 U/mL, and 31 U/mL, respectively, at pH 5. Lipase extract concentration, temperature, and storage time influenced the lipase hydrolytic activity. The optimum biodiesel yield (29.63%) was obtained at 30 °C. The addition of co-solvents (water and n-hexane) to the reaction mixture increased yields from 20.47% (without co-solvent) to 31.06% and 21.85%, respectively. These insights show that germinated rubber seeds are rich in oil and contain lipase with good hydrolytic and catalytic activity.

The industrial sector in Burkina Faso faces two significant energy challenges access to efficient energy sources that are also renewable. Pyrolysis and gasification are emerging as conversion pathways that exploit available agricultural and industrial biomass. Pyrolysis has been adopted successfully, whereas gasification failed without getting beyond the experimental stage. This article assesses potential barriers to the adoption of gasification based on interviews with the stakeholders of the energy sector (users, NGOs, policy makers). We use pyrolysis as a benchmark to point out the barriers to adoption. The hierarchical analysis process (AHP) method was applied to identify the most significant barriers to the adoption of gasification. Twenty-seven barriers were identified and prioritized in two dimensions and five categories “technical”, “economic and financial”, “socio-cultural and organizational”, “political, governmental and institutional”, and “ecological and geographical” barriers. The category of socio-cultural and organizational barriers emerged as the most critical in the adoption of gasification. This category deserves special consideration to go past the pilot installation stage and adopting this technology.

Arsenic (V) adsorption on manganese oxide coated rice wastes was investigated in this study. The modified adsorbents were characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, and pH measurements to determine the point of zero charge. Batch adsorption equilibrium experiments were conducted to study the effects of pH, contact time, and initial concentration on arsenic removal efficiency. The adsorption capacity of rice waste was significantly improved after modification with permanganate. The Langmuir isotherm model fitted the equilibrium data better than the Freundlich model which confirms surface homogeneity of the adsorbent. Maxima adsorption capacities are determined as 10 and 12 mg/g at pH 3 for manganese oxide coated rice husk and straw, respectively. The adsorption energy indicates that the adsorption process may be dominated by chemisorption. Pseudo-second-order rate equation described the kinetics sorption of arsenic with good correlation coefficients, better than a pseudo-first-order equation. Manganese oxide coated rice husk and straw appear to be promising low cost adsorbents for removing arsenic from water.