Bioenergy: Biodiesel from Freshwater Green Microalgae and a Cyanobacterium Occurring in Ghana

Biodiesel from freshwater green microalgae, and cyanobacteria holds promise as an alternative to replace petroleum diesel to meet the energy demands for transportation, industry and domestic use. In this study, three green freshwater microalgae (Closterium acerosum Ehrenberg ex Ralfs, Oedogonium ciliatum Pringsheim ex Hirn, and Spirogyra africana (F.E.Fritsch) Czurda), and a freshwater cyanobacterium (Chroococcus turgidus (Kützing) Nägeli) occurring in Ghana, were assessed to verify their suitability for biodiesel production. Samples of the species were collected from the Weija Lake; and the green freshwater microalgae were cultured in Bold’s Basal Medium while the cyanobacterium was cultured in BG-11 (Blue-Green Medium) medium, in photo-bioreactors for 14 days. Algal lipids were extracted from dry biomass of the species with hexane and diethyl ether, and biodiesel produced from the lipids by base-catalysed transesterification. The amount of lipid extracted from the species varied from 20.3 in Spirogyra to 38.2% dry wt. in Oedogonium. Biodiesel produced also varied from 6.7 in Spirogyra to 22.3% dry wt. in Closterium, and the values fell well within the range reported for such organisms around the world. We suggest that many more microalgae occurring in Ghana should be sampled for their lipid content in future work on biodiesel production and development in the country

Production of Biodiesel from Marine Macroalgae occurring in the Gulf of Guinea, off the Coast of Ghana

The purpose of this study was to determine the suitability of marine macroalgae (also known as seaweeds), from the Gulf of Guinea, off the coast of Ghana, for the production of biodiesel as an alternative to liquid fuels like gasoil and gasoline. Five green marine macroalgae species: Caulerpa taxifolia, Chaetomorpha antennina, Chaetomorpha linum, Ulva fasciata, and Ulva flexuosa, were collected from the coastal waters of Ghana at West Tema Rocks during low tide. Algal lipids were extracted from dried algae biomass with hexane and diethyl ether. Biodiesel was produced from algal lipids by base-catalysed transesterification, with alcohol. The lipid content of samples was highest in C. linum (1.13 g; 5.65% dry wt.) and lowest in C. antennina (0.54 g; 2.70% dry wt.). Similarly, the quantity of biodiesel produced from the lipids was highest in C. linum (0.97 g; 4.85% dry wt.) and lowest in C. antennina (0.48 g; 2.40% dry wt.). The quantity of biodiesel produced from samples of the five species fell well within the range obtained for such species worldwide. The implications of the yield of biodiesel for commercial production and future work on marine macroalgae from Ghana as source of biofuel are discussed

Pesticides Bioconcentration Potential of Aquatic Plants in the Volta Lake

The Volta Lake is known for the proliferation of numerous aquatic plants in its shallow waters. A major cause for the presence of the luxuriant vegetation is the intensive agricultural activities along the banks. These activities are heavily dependent on agrochemicals including fertilizers, which eventually get into the aquatic ecosystem via water ways. In this study, two aquatic plants; Ceratophyllum demersum and Nymphaea lotus were investigated in a pilot study to determine their bioconcentration of pesticides. Levels of organochlorine (OCs) and synthetic pyrethroids (SPs) were analysed using gas chromatograghy equipped with electron capture detector while gas chromatography equipped with pulse flame photometric detector was used for the organophosphorus pesticides (OPs) determination in the plant tissues. The ambient concentrations of these pesticides in the aqueous medium were also determined and the ratios of pesticide concentration in the plant and water samples estimate bioconcentration potential of the plants. Out of 38 detected pesticides, 22 (representing 58%) were bioconcentrated by the aquatic weeds. The Bioconcentration Factor (BCF) range for Ceratophyllum demersum was 1.06 – 4,470 and that for Nymphaea lotus was 1.27 – 800. By the standard of the European Union regulation for registration of chemicals, levels of diazinon and chlorpyrifos in Ceratophyllum demersum fulfilled the ‘bioaccumulation’ criterion (i.e BCF > 2000) while fenitrothion, with BFC of 5500 in the same plant fulfilled ‘very bioaccumulation’ criterion (BCF ≥ 5000). This study shows that aquatic weeds in their natural ecosystem have the remediation potential, though to varying degrees and hence play a role in the improvement of water quality

Rheophytes of Africa – A review

The unique biological group of rheophytes are plant species confined to the beds and banks (below the flood level) of streams and rivers. Rheophytes are poorly known in Africa and until now have hardly been studied. A preliminary list of African rheophytes is presented. One hundred and twelve species from 18 families are accepted as rheophytes for Africa and their peculiar characteristics and distribution in continental Africa are discussed. We wish to draw the attention of African botanists to this fascinating, yet uninvestigated group of plants. JOURNAL OF THE GHANA SCIENCE ASSOCIATION Volume 1 Number 3, July (1999) pp. 133-14

Anharmonic perturbation of neutron-proton pairs by the unpaired neutrons in heavy finite nuclei

7-15The properties of a finite heavy nucleus in which the number of neutrons N is not equal to the number of protons Z, N > Z, have been studied. It is assumed that the core of the nucleus is composed of proton-neutron pairs and the excess neutrons constitute the surface region of the nucleus. The interaction between a neutron and a proton constituting the neutron-proton pair is assumed to be harmonic. The unpaired neutrons in the surface region are assumed to interact with the neutron–proton pairs in the core of the nucleus anharmonically. Many body perturbation theory has been used to calculate the total energy of the nucleus, and thereby, we have calculated the binding energy per nucleon, called the binding fraction, the specific heat and the transition temperature. Speculation, as to how the alpha, beta and gamma radiations are emitted by a heavy nucleus, is also presented

Enigmatic morphology of Djinga felicis (Podostemaceae-Podostemoideae), a badly known endemic from northwestern Cameroon

Djinga is a monotypic genus restricted to the Cameroon Ridge ('Dorsale Camerounaise') of NW Cameroon. Besides the type locality Mount Djinga (Adamawa Province, near Tignère), it also grows in waterfalls near Mount Oku (NW Province). This paper describes the structure and development of Djinga felicis using scanning electron microscopy and microtome sections. Cusset's protologue is enriched considerably. Roots are green, dorsiventrally flattened and adherent to submerged rocks. They are broad ribbons or crusts (up to 1 cm broad) which branch exogenously. Root-borne shoots (up to 17 cm) have filamentous leaves with sheaths and (occasionally) attached stipules. Flowers are borne as part of reproductive short shoots which arise exogenously along the stems and endogenously along the roots. Djinga shows non-axillary stem branching. Reproductive shoots along the main stem usually stay short. They arise from the abaxial side of double-sheathed leaves, a key innovation of Podostemoideae. These short shoots shift into pocket-like stem positions clearly below their associated leaves. Each flower bud inside a spathella is erect, but with an inclined ovary. The flowers are unistaminate with a broad connective. Unlike many other Podostemoideae, the tricolpate pollen grains are arranged in both dyads and monads. The ovary is globular and unilocular. The mature 8-ribbed capsule dehisces by two slightly unequal valves, releasing 40–50 seeds