No abstract

No abstract

Investigations were conducted to compare gas produced from co-digestion of corncob, rice chaff, goat dung and dog dung with commercial gas. The study was carried out anaerobically at a temperature of 29.5 to 33°C (mesophilic condition) in a mini laboratory digester (bioreactor) fabricated using guage 16 metal sheets with 80-L capacity for a 90-day retention time. The shredded corn cob and rice chaff were mixed with water at ratio 4:1 (waste to water) and 3:1 (waste to water) respectively and mixed with goat and dog dungs at ratio 2:1 (waste to water). The control sample collected from a domestic cooking gas cylinder contained 56.12% CH 2 , 0.14% NH 3 , 0.22% CO, 0.23% H 2 S and 43.20% CO 2 . The result obtained for the biogas analysis shows that Sample E (75:25) contains 63.54% CH 4 , 0.93% NH 3 , 0.84% CO, 0.54% H 2 S, 34.12% CO 2 . The value recorded for sample E represented the highest value obtained among the samples. Also the gas composition shows a good substitute for commercial gas.

Microorganisms are regarded as the oldest and most abundant life form on earth and their importance to man cannot be over emphasized. They are the occupants and architect of the biosphere maintaining metabolic cycles essential for life. The aim of the study was to explore the benefits and detriments of bacteria associated with kolanut soil plantation and waste to man and the environment. Bacterial was isolated from kolanut soil plantation, decayed, decaying and fresh kolanut waste (testa and husk) obtained from Ilara-Mokin (Ondo State) and Owena-Osun (Osun State), Nigeria following standard procedures. Thirteen isolates with distinctive morphological and physiological characteristics were identified using molecular techniques and Sanger sequencing was employed to detect labelled chain-terminating nucleotides that are incorporated by DNA polymerase during replication of the templates. The genus of bacteria identified included; Bacillus, Enterobacter, Citrobacter, Klebsiella, Pseudomonas, Marinobacter, Staphylococcus, Lysinibacillus, Providencia, Erwinia. The most dominant genus however was the Bacillus, Pseudomonas and Citrobacter. A good number of the bacteria isolated can be explored for production of products such as enzymes, use as biocontrols and for environmental cleanups.

The objective of this research was to know the effect of water hyacinth (Eichhornia crassipes) on the quality of cow dung biogas. Water hyacinth (Eichhornia crassipes) is a perennial aquatic herb, which belongs to the family Pontedericeae. It is usually found floating freely on the surface of fresh water or can be anchored in mud. Using water hyacinth as a biogas is one of the ways to limit the disadvantageous effects of the plant and to provide a low-cost gas. Seventy five percent cow dung was mixed thoroughly with 25% blended water hyacinth (3:1) and cleaned water was added to form slurry, it was poured through the inlet orifice of a digester. Bacteria and mould counts of the materials were determined before and during digestion. Temperature, pH, of the digesting materials, biochemical and morphological characterization of the isolates were carried out to know the microorganisms responsible for the digestion of the materials. A total of eight (8) bacteria and four (4) fungi were isolated during digestion. The bacteria identified were Escherichia coli, Methanococcus mazei, Enterobacter aerogenes, Clostridium welchii, Methanobacterium ruminantium, Lactobacillus delbrueckii, Methanothrix sochngenii, Klebsiella pneumoniae and the fungi isolated included Aspergillus flavus, Aspergillus niger, Aspergillus fumigatus and Mucor mucedo. The pH of the digesting material was between 5.40 and 7.28. The temperature was from 30°C to 39°C. The result of the biogas analysis was 91.10% methane (CH4), other traced gases was 6.43%, while ammonia (NH 3 ) was not detected. Twenty five percent (25%) water hyacinth added to the seventy five percent cow dung in ratio 3:1 showed that water hyacinth could be mixed with cow dung to improve the methane quality of the biogas. This could contribute to the reduction of environmental pollution.