With increasing concerns over fossil fuel depletion and environmental pollution, research into alternative energy sources has gained significant momentum. Organic wastes, particularly from animals and food, offer a promising substrate for biogas production, providing dual benefits of energy generation and waste reduction. This study evaluates the suitability of food waste, cow regurgitates, and cow dung for biogas production through biodigestion. The objectives were to design a lab-scale biodigester, compare biomethane yields from each waste, and evaluate their effectiveness as fertilizers. The results indicate that all three samples have properties within the acceptable range for digestion. Food waste exhibited the highest methane yield with a daily biogas production of 0.4979 m³/day, corresponding to an energy content of 27,699.45 KJ/day. Cow regurgitates produced 0.2656 m³/day of biogas, yielding an energy content of 14,739.6 KJ/day. Cow dung yielded 0.3213 m³/day of biogas, translating to an energy content of 17,723.65 KJ/day. Microbial analysis indicated the presence of beneficial bacteria and fungi, such as Staphylococcus spp, Proteus vulgaris, Escherichia coli, Enterobacter aerogens, Aspergillus spp, and Mucor spp, which are advantageous for soil conditioning and nutrient cycling. The study highlights the importance of assessing physicochemical properties, nutrient content, and microbial composition to optimise biogas production and explore the potential of organic waste as a sustainable energy source and soil conditioner.

This study investigated the performance of Garcinia kola exudates in preventing mild steel exposed to acid concentrated water and soil. The study was performed in order to find an alternative coating substance that can reduce the corrosion of mild steel pipes exposed to corrosive water and soil media. Various mild steel specimens were cut into portions and coated with the exudates at 25 - 50µm thickness. To accelerate the rate of corrosion, 0.5M hydrochloric acid (HCl) was added to tap water in a container. Also, the same concentration of HCl was equally added to soil samples. Uncoated mild steel specimens were immersed in the acid concentrated water and soil, servicing as control sample. The rate of corrosion was monitored for 30 days (720 hours). The inhibition efficiency of the exudates for both corrosive media was compared. Results showed that the weight loss and corrosion rate of mild steel decreased with increase in coating thickness. Comparatively, weight loss and corrosion rate in the uncoated specimens were higher than the coated specimens. For uncoated specimens, the corrosion rate was 0.2793mm/yr and 0.4150mm/yr for specimen immersed in water and soil respectively, but at 25µm coating thickness, it decreased to 0.01369mm/yr and 0.2870mm/yr for specimens in water and soil. Also, at 50µm coating thickness, corrosion rate decreased to 0.0052mm/yr and 0.0318mm/yr for specimens in water and soil, respectively. The inhibition efficiency increased with coating thickness, ranging from 51.00 – 98.15% for specimens immersed in water and 30.84 – 92.33% for specimens buried in soil at 25µm – 50µm coating thickness. The results demonstrated that Garcinia kola exudates can be used as corrosion inhibitor for mild steel exposed to corrosive media.

Proximate and phytochemicals are chemical components that are derived from plants through metabolic activities, Polyalthia longifolia is a very important plant. The phytochemical analysis results obtained for the bark for alkaloid, saponins, flavonoid, total phenol, hydrogen cyanide and terpenoid are as follows; 8.13, 9.31, 9.41. 42.7, 0.01 and 4.47 and for the leaves. 4.84, 3.21, 7.14, 2.96, 1.73 and 4.11 respectively. the proximate results carried out on its bark using standard procedures shows it contains (%) carbohydrate 51.7, moisture content 12.8, ash content 10.52, crude fibre 15.31 and crude protein 7.22 and the proximate results for leaves 4.48, 3.21, 7.14, 2.96 and 4.11 respectively for carbohydrate, moisture content, ash content, crude fibre and crude protein. This result shows that the plant is a good source of saponin, alkaloid, phenols, and terpenoids which contribute to the nutritive and medicinal potency of the plant. The concentration of hydrogen cyanide in the plant leaves and bark is not significant and therefore will have no lethal effect and can easily be detoxified but comparatively the leaves contain more cyanide than the bark which could be related to the moisture content, the total penol in the bark is also significantly higher than the leaves which show its effectiveness as an anti microbial agent. The high percentage of carbohydrate shows that the plant can be a good source of energy for both humans and animals. This plant has several benefits like anti-cancer, anti-oxidants and anti-haemohorrds and can be used to reduce fibroid, it is applicable industrially as food preservatives, cosmetics and sweetners,