Investigation of No2/No, So2, Co and Volatile Organic Compounds Emission from Solid Waste in Ogbomoso

Emissions from burning of solid waste have been a major source of air pollutions in Ogbomoso Township in the last few years. This research work estimate the emissions of nitrogen oxides (NO2/NO), carbon(II)oxide, sulphur (iv) oxide and volatile organic compounds from solid waste in Ogbomoso as a measure of control using the emission factors approach. Determination of the solid waste generation potential using per capita approach was combined with the appropriate emission factors for the estimation. On the average, nylon has the least generation potential with 8.85% while solid (glass, metal, tin and sand) has the highest with 44.825%. These generation potentials increased from 44,073 tonnes/annum in the year 2002 to 63,822.88 tonnes/annum in the year 2011 with the population of 242,167 to 350,627 per capita respectively. However, results obtained from nitrogen oxides (NO2/NO), carbon (II) oxide, sulphur (iv) oxide and volatile organic compounds emissions rate shows an increased trend of 132.22 to 191.47, 1851.3 to 2680.6, 19.3 to 27.1 and 947.58 to 1372.19 tonnes/annum respectively in the year 2002 to 2011. The emission rate of NO/NO2, SO2, CO and volatile organic compounds must be controlled because of their adverse effect on the environment. The controlled could be by converting them for energy production owing to the high calorific value of the solid waste in Ogbomoso. Another controlled technique that can be employed in addition to conversion for energy production is by burning the waste in an incinerator since the solid waste consist of high percentage of combustible materials. Keywords: Emission factor, Solid wast

Sustainable hydrogen generation substrates, catalysts and methods : an overview

Abstract: Because of the increasing demand for energy, various alternative sources of energy generation are being examined. Interest in hydrogen generation is on the rise due to its potential as a scalable green energy source, its transportability, and other positive factors. While various studies have been conducted on hydrogen generation, this review explores three major factors in hydrogen generation in relation to sustainability: substrates or hydrogen storage media, catalysts for speeding up the rate of hydrogen reaction, and methods employed. The media used to store the hydrogen, such as metal hydrides and complex hydrides, is examined in relationship to hydrogen yield, ease of hydrogen generation or treatment, cost and environmental friendliness. A list of popular catalysts - particularly precious/rare earth metals, strong acids and weak acids - is examined and compared in terms of hydrogen yield, environmental friendliness, and cost. The recent trend in hydrogen generation techniques and material treatment innovations such as hydrolysis, and ball milling of nanocomposites is examined. Innovations in hydrogen storage material selection and techniques will go a long way in lowering hydrogen generation cost, increasing hydrogen yield and ameliorating negative environmental impacts

MODELLING OF GROUND LEVEL CONCENTRATION OF PARTICULATE MATTER IN MAJOR NIGERIAN UNIVERSITY AIRSHED

Modelling of air pollutants for air quality assessment has been an important landmark achievement by environmentalists especially in areas where on-the-field monitoring is not economical. Models have proven to be cost-efficient and predicts better with different sample sizes. The objective of this study was to model the particulate matter pollutants of a major Nigerian university airshed and to compare of the predicted results with regulatory standards. Dispersion modelling analysis using for line and point sources study of the university airshed was carried out. Prior to the use of the modelling tool, vehicular counts, emission estimation and loads for the two pollution sources was done. The predictions revealed that concentration levels of PMs to emission source and receptor environments for the line source study were extremely high due to factors such as emission height and meteorological conditions of the university. The predicted concentrations from the point source were moderate and the reason is due to the emission height (stack height), wind speed and direction. Other contributing sources could be as a result of biomass burning, bush burning and pollutant transport. This study will be a bedrock for institutional-based air quality assessment that checkmate the anthropogenic contribution to deteriorating ambien

PROJECTION OF CRITERIA AIR POLLUTANTS EMISSION FROM ON-ROAD VEHICLES IN THE MEGACITY OF LAGOS, NIGERIA

The increase in the mode of transportation has become a serious environmental threat that has resulted in the emission of criteria air pollutants (CAPs) into the atmosphere. These CAPs are sulphur oxides (SOx), particulate matter (PM), lead (Pb), carbon monoxide (CO), and nitrogen oxides (NOx). This study examined the emission of CAPs from road traffic use in Lagos State. Data for the inventories of the production of these five sources were taken from 1997–2011 and were used to forecast CAPs emissions from 2012–2030. The petroleum products consumption data were sourced from the Nigerian National Petroleum Corporation (NNPC). Five categories of CAPs were studied and their corresponding emissions from 1997–2011 were computed as follows: SOx: 209–15,358t, NOx: 2,038–25,692t, CO: 24,996–186,202t, PM: 155–995t, Pb: 0.8 4.5t. Projection and forecasting of CAPs emissions from 2012 to 2030 were carried out using the Box Jenkins ARIMA method. There were close similarities between the observed and forecast values. The predicted CAPs emissions between 2012 to 2030 will be 309t for SOx, 22,600 – 41,300t for NOx, 100,000 – 300,000t for CO, 414t for PM, and 0.7t for Pb. The study concluded that there is tendency for these CAPs emissions to increase if the authorities and stakeholders do nothing. Several mitigation measures aimed towards reducing future CAPs emissions in Lagos State were recommended for the various sources

Application of the triangular model in quantifying landfill gas emission from municipal solid wastes

Municipal solid waste landfills are significant parts of anthropogenic greenhouse gas emissions. The emission of significant amount of landfill gas has generated considerable interest in quantifying such emissions. The chemical composition of the organic constituents and potential amount of landfill gas that can be derived from the waste were determined. The chemical formulae for the rapidly biodegradable waste (RBW) and slowly biodegradable waste (SBW) were determined as C39H62O27N and C36H56O20N, respectively. The triangular method was used to calculate landfill gas obtainable from rapidly biodegradable waste over a 5-year period and for slowly biodegradable waste over a 15-year period. A plot was obtained for a landfill life span of 20 years. The volume of methane and carbon dioxide from RBW were 12.60 m3 and 11.76 m3 respectively while those from SBW were 6.60 m3 and 5.48 m3 respectively at STP. For the initial deposit of 2002 the highest landfill gas emission rate occurred in 2007 at 0.2829 Gg/yr with an average cumulative emission of 0.3142 Gg while for a landfill closed after five years the highest landfill gas emission rate was in 2010 at 1.2804 Gg/yr with an average cumulative emission of 1.5679 Gg while this cumulative emission will start declining by the year 2029

Purification, characterization and toxicity of a mannose-binding lectin from the seeds of Treculia africana plant

In this study, a mannose-specific, homodimeric lectin from the seeds of Treculia africana was purified, characterized and its adverse effects were investigated in mice. The purification protocol involved anionic exchange chromatography on DEAE-Cellulose followed by gel filtration on Sephadex G-100. The hemagglutinating activity of lectin towards human erythrocytes was sensitive to inhibition by D-mannose. Treatment of the protein with EDTA exerted no inhibitory effect; however, analysis of metal content by atomic absorption spectroscopy revealed the presence of Cu2+, Fe3+, and Mg2+. The results obtained showed that the lectin possesses maximum hemagglutinating activity towards human erythrocytes activity over the pH range 3–7.2 and is relatively thermostable up to 50°C. Periodic acid Schiff's (PAS) reagent staining showed that the protein was non-glycosylated while its amino acid composition analysis revealed that the protein contained 155 residues per subunit. The subunit had a minimal molecular weight of 22,139 Daltons, while the native molecular weight was estimated to be 41,000 Daltons. The lectin was found to be moderately toxic to mice with an LD50 of 47.21 µg g−1 body weight while, histopathological analysis showed no treatment related effects in any of the organs examined