Physico-chemical properties of well water samples from some villages in Nigeria with cases of stained and mottle teeth

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Determination of selected metals in coal samples from Lafia-Obi and Chikila

The concentration of iron, aluminum, chromium, magnesium cadmium, potassium, lead and copper in Lafia-Obi and Chikila coal samples were determined using atomic absorption spectroscopy (AAS). All the samples have comparable chromium and copper contents, while iron, aluminum, magnesium and potassium content vary to some extent. Metals concentrations in both Lafia-Obi and Chikila coal samples are within the limits allowed by the Federal Environmental Protection Agency (FEPA) except in Chikila (UBCJ-1) and Lafia-Obi (MBJJ-6) coal samples where iron was observed to be higher than the stipulated 20 ppm. These show that the disposal of ash generated from the combustion of these coals may not pose a potential threat to environment. Key words: Coal ash, environment, heavy metals, pollution, proximate analysis, Atomic Absorption Spectroscop

Acceptance of Aerial Yam (Dioscorea bulbifera L.) for Food in Biu Emirate Council, Borno State, Nigeria

Aerial yam is a semi-wild food that grows on vines climbing onto poles and trees. The bulb is eaten on peeling off the hard back after cooking. Questionnaire was administered to investigate its acceptance for food in Biu environ as well as its taste. Proximate analysis was carried out to determine its nutritive value. About 85% of the respondents eat aerial yam as a supplement to their major food or meals. The result shows that elderly people of 36 years and above (58.83% of respondents) eat aerial yam being a common resource and cheap in the dry season. The taste varied with individuals as 58.82% stated that it is tasteless; 17.66%, bitter and 11.76%, indefinite. The samples analysed gave an average of 32% DM; 3.61%, CP; 3.06%, EE or fat; 8.65%, CF; 1.33%, ash and 83.56%, NFE. The integration of aerial yam in cropping system is therefore recommended as it has such a nutritional profile and ease of production. Keywords: Aerial yam, Consumption, Taste, Nutritive value

The Effects of Flame Retardants on Combustion of Some Tropical Woods

Penta-erythritol, melamine and diammonium hydrogen orthophosphate were doped into emulsion paint and painted into some tropical woods that are commonly used for building, furniture, and other construction. These woods are Daniellia oliveri, Anogeissus leiocarpa, Mansonia altissima and Vitex doniana. The woods were also doped with a combination of urea fertilizer and alum dissolved in water. Paint formulations were prepared by using a combination of penta-erythritol, melamine and diammonium hydrogen orthophosphate and alone with gypsum. Some woods were painted with the formulations. The flame retardation effects of each of these formulations on the combustion of these tropical woods were determined through the following combustion parameters; ignition time, flame time, after glow, char length, flame propagation rate, moisture content and percent add-on. It was observed that the flame retardants really had retardation effect on the combustion of these tropical woods. The order of the degree of their retardation effects, a combination of urea fertilizer and alum is the highest, followed by paint mixed with gypsum and lastly, paint doped with penta-erythritol, melamine and diammonium hydrogen orthophosphate. Keywords:  Flame retardants, wood, combustion, paint, perservative

Mineral Matter in Nigerian Coals and Tar Sand and Their Implications in Binary Blend Formulation and Co-Carbonisation

In blend simulation for metallurgical applications, the knowledge of the type and amount of mineral matter in coal and other additives, as well as their derivatives as a result of combustion is important in assessing the coke quality and blast furnace efficiency. X-ray diffraction (XRD) and X-ray fluorescence (XRF) techniques were used in assessing the mineral matter contents and oxides produced up on combustion of the following Nigerian coals: Afuze (AFZ), Garin-Maiganga (GMG), Lamza (LMZ), Shankodi-Jangwa (SKJ), and Chikila (CHK) in addition to a tar sand from Ondo (OTS). Coal samples from Afuze (AFZ) and Chikila (CHK) were found to contain quartz, hematite, and anhydride as the dominant minerals. The Garin-Maiganga coal sample (GMG) was found to contain quartz, magnetite, anhydride, and magnesite. Quartz and hematite were dominant in Lamza coal (LMZ), while Shankodi-Jangwa coal (SKJ) is associated with dolomite and quartz. The bitumen was found to contain quartz, kaolinite, and rutile. The XRF analysis revealed the presence of sixteen elemental oxides: the most abundant being silicon dioxide, ferric oxide, aluminium oxide, sulphur trioxide, calcium oxide, and titanium oxide. Amongst the coal samples, CHK, AFZ and GMG coals have low acidic/basic and basic/acidic ratios, which indicate that cokes originating from them may form the least slag with the best blast furnace efficiency

Combustion kinetics of Shankodi-Jangwa coal

The lack of comprehensive data on the fuel properties of newly discovered coal deposits in Nigeria has hampered the prospective utilisation for power generation. Consequently, this study is aimed at characterising the physicochemical and thermokinetic properties of Shankodi-Jangwa (SKJ) coal recently discovered in Nassarawa state, Nigeria. The results indicate that SKJ comprises 40.50% fixed carbon, 43.34% volatile matter, and 2.36% sulphur with a higher heating value (HHV) of 27.37 MJ kg-1. Based on this HHV, SKJ was classified as high-volatile B bituminous coal. Thermal analysis of SKJ under oxidative thermogravimetry (TG) at multiple heating rates revealed that SKJ is highly reactive and thermally degradable below 1000°C. Kinetic analysis using the Flynn-Wall-Ozawa model for conversions α = 0.05-0.90 revealed the activation energy to range from Ea = 113-259 kJ mol-1, with the frequency factor ranging from A = 2.9 × 1013-1.5 × 1023 min-1 and a range in R2 = 0.8536-0.9997; the average values of these ranges are Ea = 184 kJ mol-1, A = 9.2 × 1023 min-1 and R2 = 0.9420, respectively. The study highlighted fuel property data vital for modelling and designing future SKJ coal power generation

Assessment of Some Nigerian Coals for Metallurgical Application

In the quest for a search of a suitable coal deposit of metallurgical importance, the qualities of three Nigerian coal samples, Lafia-Obi, Doho and Lamja, were assessed for possible utilization in metallurgical coke production. Several parameters that determine coking quality, such as moisture content, ash, volatile matter, free swelling index, sulphur content, Gray-King coke test, dilatation and plasticity (fluidity), were investigated. Lafia-Obi has the lowest moisture and volatile matter and the highest fixed carbon content. Its ash and sulphur contents are greater than that required by a coking but washing prior to use is expected to improve it. The volatile matter places Lafia-Obi in the medium-volatile bituminous rank, while Lamja and Doho are of medium-volatile bituminous rank. The rheological properties show that Lafia-Obi is the only caking coal. This put together single out Lafia-Obi as a potential candidate for coke making. Doho and Lamja coals may be useful for steam raising, liquefaction or chemicals manufacture

Comparative Analysis of Physicochemical Properties of Dimer Acids from Jathropha Curcas and Thevetia Nerrifolia Seed Oils

Thevetia Nerrifolia and Jathropha Curcas seed oils were extracted from their oil seeds by soxhlet extraction using petroleum ether (40-60 oC) as solvent. The oils were characterized and the oil yield, refractive index, acid value, saponification value, iodine value, colour and relative density were found to be 47.77%, 1.464, 4.365 (mg/KOH), 125.62 (mg/KOH), 98.48 (wij), 4+ and 0.926 for Thevetia Nerrifolia seed oil and 46.56%, 1.496, 33.65 (mg/KOH), 175.12 (mg/KOH) 105.43 (Wij), 3 and 0.913 for Jathropha Curcas seed oil respectively. Dimer acids were prepared from these seed oils by heating 200g of each of the oils under nitrogen inert atmosphere in a four necked resin kettle at a temperature of 300oC for 12 hours. The physicochemical properties of the dimer acids were analyzed and were found to compare favourably with each and other well known feed stocks of dimerization

Petrology, Physicochemical and Thermal Analyses of Selected Cretaceous Coals from the Benue Trough Basin in Nigeria

Abundant coal resources that were previously neglected due to a crude oil boom need revitalisation and integration into the national electricity mix to address the energy demands of the Nigerian population. Selected coal samples from the Benue Trough sedimentary basin in Nigeria were examined by various techniques, including proximate and ultimate analyses, organic petrography, Fourier transform infrared ray spectroscopy, and thermogravimetric analysis. Based on vitrinite reflectance, the Lafia-Obi (OLB), Garin Maiganga (GMG), Imiegba (IMG), and Okaba (OKB) coals are classified as subbituminous, while the Lamja1 (LMJ1), Lamja2 (LMJ2) and Chikila (CHK) coals are high volatile B bituminous. The Enugu (ENG) coal is on the boundary between subbituminous and high volatile C bituminous. Organic petrographic results indicate vitrinite and fusinite contents steadily increase from the Lower Benue Trough coals to the Upper Benue Trough coals, while semifusinite and total mineral contents follow a reverse pattern. Thermal decomposition occurred in three stages, i.e., drying, devolatilization, and coke formation above 700 °C; and the coal reactivity follows the following order, ENG \u3e IMG \u3e IGH \u3e CHK \u3e LMJ \u3e OKB \u3e GMG \u3e LFB. The higher temperatures (above 900 °C) are required to decompose the coals for efficient energy recovery. The LMJ1, LMJ2, OLB, CHK, GMG, and OKB coals can be exploited for electricity power generation. However, the Imeagha and Enugu coals are best suitable for both cement and power generation