Search Results (5)

Three wastewater sources, namely slaughterhouse wastewater, cheese whey, and wine lees, were used for volatile fatty acid (VFA) production with the aim of reducing polluted wastewater discharge to the water bodies and creating a useful product. Cheese whey and wine lees were proved to be good substrates to produce VFAs, obtaining maximum bioconversion percentages in g COD-VFA/g TCOD initial of 90% and 72% for cheese whey and wine lees, respectively. The composition of the VFAs produced from each wastewater stream varied, with acetic, propionic, isobutyric, and isovaleric acids being the most dominant. These VFAs were used as an environmentally friendly fungicide against Fusarium culmorum, resulting in a reduction of the radial mycelial growth of Fusarium culmorum for all the effluents tested. A thermal pretreatment of the VFAs resulted in an improved antifungal efficiency if compared to the untreated VFAs or a UV pretreatment. Full article

Climate change has become a global nightmare, and the awareness of the causes of carbon emissions has resulted in rigorous studies. These studies linked the increase in global warming with booming economic growth. Since global warming has become more apparent, researchers have explored ways to decouple economic activities from carbon growth. Economic and carbon growth must be decoupled to achieve a low-carbon economy to support the carbon-growth plan or emission-reduction strategy. The world is transitioning toward a carbon-neutral and green ecosystem, so finding ways to decouple carbon emissions from economic activities is an exciting topic to explore. This study reviews current information on the importance of decoupling energy from economic growth innovative techniques that thoroughly examine the challenges and constraints of low-carbon energy systems. In order to examine the detrimental effects of carbon emissions on ecosystems and the ways in which economic expansion contributes to carbon footprints, more than three hundred research papers were gathered using several search engines, including Elsevier and Google Scholar. This review revealed that decarbonization and dematerialization had been achieved without declining global economic growth. It also provides information on energy use and economic activities leading to global carbon emissions and alternative solutions to the global challenge of climate change. The decoupling methods commonly used to determine the impact of energy decarbonization on economic growth are explored. All the results suggest that economic growth is a primary mover of global carbon emission increase and must be separated to achieve a carbon environment. Full article

The optimization and modeling of the parameters, the concentration of polylactic acid (PLA), sugarcane bagasse cellulose fibers (SBCF), and snail shell nanoparticles (SSNP), were investigated for the development of bioplastic films. With the aid of the Box–Behnken experimental design, response surface methodology was used to assess the consequence of the parameters on the water absorption and thermal stability of fabricated bioplastic films. Varied water absorption and thermal stability with different component loading were obtained, evidencing the loading effect of snail shell nanoparticles and sugar bagasse cellulose fibers on bioplastic film’s water absorption and thermal stability. The quadratic polynomial model experiment data offered a coefficient of determination (R²) of 0.8422 for water absorption and 0.8318 for thermal stability, verifying the models’ fitness to develop optimal concentration. The predicted optimal parameters were polylactic acid (99.815%), sugarcane bagasse cellulose fibers (0.036%), and snail shell nanoparticles (0.634%). The bioplastic developed with optimized concentrations of each component exhibited water absorption and thermal stability of 0.45% and 259.7 °C, respectively. The FTIR curves of bioplastic films show oxygen stretching in-plane carbon and single-bonded hydroxyl bending in the carboxylic acids functional group. SEM and TEM images of the bioplastic showed dispersion of the nanoparticles in the matrix, where SSNP is more visible than SBCF, which may be due to the lesser loading of SBCF. The improved properties suggest an optimum concentration of naturally sourced resources for developing bioplastic, which may be used for food and drug packaging for delivery. Full article

γ-Valerolactone (GVL) is a platform chemical for the synthesis of both biofuels and biochemicals. The LA production from depithed sugarcane bagasse (DSB) resulted in a 55% LA yield, and the resulting LA was used to produce GVL. The effect of process parameters, namely, temperature (25–200 °C), time (2–10 h), and catalyst loading (0.5–5 g) were investigated for the GVL production from LA. Thereafter, the optimized conditions were used to produce GVL from LA derived from depithed sugarcane bagasse (DSB) yielded a GVL of 77.6%. The hydrogen required for the reduction of LA to GVL was formed in situ by formic acid and triethylamine in the presence of methanesulfonic acid (MsOH). Different solvents (including water and alcohols) were also tested to determine their effect on GVL yield, and water yielded the highest GVL of 78.6%. Different types of catalysts, which included mineral acids and ionic liquids, were used to determine their effect on GVL yield, and to provide a benchmark against MsOH. The GVL yield from DSB-derived LA is 1.0% lower than the GVL yield from a commercial sample of LA. LA generated from DSB has the potential to replace fossil fuel-derived LA. Full article

Bioenergy production from waste is one of the emerging and viable routes from renewable resources (in addition to wind and solar energy). Many developing countries can benefit from this as they are trying to solve the large amounts of unattended garbage in landfills. This waste comes in either liquid (wastewater and oil) or solid (food and agricultural residues) form. Waste has negative impacts on the environment and, consequently, any form of life that exists therein. One way of solving this waste issue is through its usage as a resource for producing valuable products, such as biofuels, thus, creating a circular economy, which is in line with the United Nations (UN) Sustainable Development Goals (SDGs) 5, 7, 8, 9, and 13. Biofuel in the form of biogas can be produced from feedstocks, such as industrial wastewater and municipal effluent, as well as organic solid waste in a process called anaerobic digestion. The feedstock can be used as an individual substrate for anaerobic digestion or co-digested with two other substrates. Research advancements have shown that the anaerobic digestion of two or more substrates produces higher biogas yields as compared to their single substrates’ counterparts. The objective of this review was to look at the anaerobic digestion process and to provide information on the potential of biogas production through the co-digestion of sugarcane processing wastewater and municipal solid waste. The study deduced that sugar wastewater and municipal solid waste can be considered good substrates for biogas production in SA due to their enormous availability and the potential to turn their negative impacts into value addition. Biogas production is a feasible alternative, among others, to boost the country from the current energy issues. Full article