The Potential of Some Non-Conventional Vegetable Oils in Biodiesel Applications

This work studied the potentials of some non-conventional oils biodiesel as an alternative to biodiesel made from a conventional seed oil (palm kernel oil), and petroleum-based diesel. The fruits of three non-conventional oilseeds, namely:PerseaAmericana (Avocado pear), Irvingiagabonenses (Dica nut) and Darcryodesedulis (Native pear)were obtained from local markets in Ile-Ife, Osun State Nigeria while petroleum-based diesel (PBD) used for comparative study was obtained commercially.The outer fleshylayers of the fruitswere separated from the seeds while both were air-dried for some days and later milled. The oils extracted from the milled samples were esterified to produce biodiesel usingmethanol in the presence of NaOH as catalyst. The biodiesels were analyzed for their fuel properties using standard methods.Results showed that the biodiesel yield ofIrvingiagabonensisoil diesel (IGOD),Darcryodesedulisoil diesel (DEOD) and Persia americanaoil diesel (PAOD) were94%, 82% and 96% respectively. These values compared favourably with that of palm kernel oil diesel (PKOD) (91%) produced under same conditions, and with the literature standard yield of 96.5% set for biodiesel. The pour pointsof PKOD, PAOD and DEOD were3, -6 and 1oC,respectively, with PAOD pour point very close to that of PBD (≥-10oC) obtained under similar experimental conditions. Except for IGOD, all the oils have pour points within the standard range of -15 to 16oC set for biodiesel suggesting the suitability of the oils for biodiesel applications.The iodine values of the biodiesel ranged between 9.64 and 16.52 meq/kg and agreed closely with 12-18 meq/kg reported in literature for PKOD. The biodiesel blend with PBD in the ratio 10:90, 20:80, 30:70 and 40:60 demonstratedimprovedphysico-chemical properties (including smoke point, flash point, cloud point, pour point, density, viscosity and acid value) that could meet the fluidity requirements for biodiesel applications

A Comparative Study of the Removal of Heavy Metal Ions from Synthetic Wastewaters Using Different Adsorbents

A comparison has been made of the efficiency of heavy metal ion adsorption from synthetic wastewaters by charcoal prepared locally from the burnt remnants of plantain peel with more conventional adsorbents such as industrial activated wood charcoal, technical charcoal animal powder and Amberlite resin. Thus, mixed standard solutions (100 mg/ℓ) of copper and lead ions adjusted by buffer solutions to pH values of 5, 7 and 9, respectively, were allowed to flow through adsorbent columns which were 10, 20, 30, 40 and 50 cm in length. The concentrations of the heavy metal ions in the mixed standard solutions were determined before and after contact with the adsorbents via atomic absorption spectrophotometry (AAS). The adsorption capacities of the various adsorbents based on the overall percentage removal of Cu 2+ ions at pH 9 employing a column of 50 cm length were in the order: Amberlite resin (98.89 ± 7.59%) > plantain peel charcoal (98.56 ± 6.72%) > technical charcoal animal powder (96.87 ± 5.78%) > activated wood charcoal (93.64 ± 7.29%). The corresponding order for Pb 2+ ions at a pH value of 7 employing a column of 50 cm length was: Amberlite resin (99.98 ± 7.53%) > plantain peel charcoal (98.37 ± 7.95%) > technical charcoal animal powder (97.91 ± 6.83%) > activated wood charcoal (96.39 ± 7.06%)

Evaluation of polycyclic aromatic hydrocarbons and potentially toxic metals in commonly consumed pasta products available in the Nigerian markets

Background: Levels of polycyclic aromatic hydrocarbons (PAHs) and potentially toxic metals (Cd, Co, Cu, Mn, Pb, and Zn) were determined in three batches of eight types of commonly consumed pasta products (A - H) available in Nigeria. This was done in order to evaluate the health hazards associated with unguarded consumption of the products. Methods: A gas Chromatography-Flame Ionization Detector (GC-FID) was used to identify and quantify the levels of sixteen polycyclic aromatic hydrocarbons in Soxhlet-extracted fractions of powdered pasta product samples using n-hexane, while Atomic Absorption Spectrometer (AAS) was also used to quantify the levels of the metals in the acid digested pasta samples. Results: The recovery results (%R>90) confirmed the efficiency of the adopted analytical procedures. Levels of PAHs detected in the samples ranged between below detection limit (BDL) and 17.18 μg g-1 with total PAHs (μg g-1) occurring in the order: F > H > D > C > E > A > G > B. Potentially toxic metal concentrations (µg g-1) in the various pasta samples were of the order: Cd ˂ Cu ˂ Zn ˂ Mn, while Co and Pb were BDL in all the pasta samples. Conclusion: The pasta samples contained PAHs and potentially toxic metals at levels that could not cause immediate health infection but which could threaten the health of the consumers over prolonged regular consumption

Concentrations of Polybrominated Diphenyl Ethers (PBDEs) in Water from Asunle Stream, Ile-Ife, Nigeria

This study assessed the concentrations of polybrominated diphenylethers (PBDEs) in stream water obtained from Asunle stream, an adjoining stream of the Obafemi Awolowo University dumpsite. Water samples were collected for a period of eight months from six different locations comprising of a spot upstream in an uphill area relative to the refuse dumpsite and five others downstream along the stream course. The sampled waters were extracted with dicholoromethane using liquid-liquid extraction method and cleanup was carried out with silica gel. The final extracts after concentration were analyzed using GC-MS/MS. The recovery experiments were adequate (105%–110%). The mean levels of Ʃ6PBDEs compounds analyzed ranged from 0.03 to 0.45 ng/mL. Seasonal variability of PBDEs indicated that higher levels were found during the wet season. The levels of PBDEs recorded in this work were relatively lower compared to the values reported in the literature from other developed nations

Speciation study of the heavy metals in commercially available recharge cards coatings in Nigeria and the health implication

This work assessed levels of heavy metals exposure from silver coatings of mobile phones recharge cards of three major companies (designated as A, B and C) with price denominations 100, 200 and 400 from companies A, B and C respectively, which were carefully scratched using a plastic scraper into a glass tube. The coatings were acid digested for total metal concentration, while speciation experiment for Mn, Cu, Cd and Pb was carried out. Total metals and speciation analysis were done using AAS and XRF techniques. The total metal concentration from XRF analysis was in the range: Ca (70–2140 μg/g), K (20–4930 μg/g), Sc (80–270 μg/g), Ti (1530–12,580 μg/g), Fe (50–6660 μg/g), Ni (20–2040 μg/g), Cu (20–850 μg/g) and Zn (40–460 μg/g). Cr had the lowest concentration (10 μg/g) in A (400) while Ti had the highest concentration (12,580 μg/g) in C (500) for all the coatings analyzed. AAS and XRF results agreed closely except for Fe with higher concentration. A (100) contained high concentration of the metals compared with others. Speciation study identified Mn as the most mobile element when present in the environment