Trace elements in particulate matter of ambient air at petroleum filling stations

Size segregated suspended particulate matter (PM_2.5 and PM_10-2.5) in air at four major petroleum-filling stations in Ile-Ife, Nigeria, were monitored using double staged “Gent” stacked samplers to assess variations in mass loads and elemental concentrations of 25 elements. Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, Zr, Cs, Ta, W, and Pb were determined in both fractions by external ion beam proton-induced X-ray emission technique. Enrichment factors and pollution indices were calculated and results revealed that most elements were anthropogenic in both fractions with concentrations exceeding the World Health Organization guideline standards.     

Climate change mitigation policy paradigms—national objectives and alignments

The aim of this paper is to assess how policy goals in relation to the promotion of green growth, energy security, pollution control and greenhouse gas (GHG) emissions reductions have been aligned in policies that have been implemented in selected countries during the last decades as a basis for discussing how a multi objective policy paradigm can contribute to future climate change mitigation. The paper includes country case studies from Brazil, Canada, China, the European Union (EU), India, Japan, Mexico, Nigeria, South Africa, South Korea and the United States covering renewable energy options, industry, transportation, the residential sector and cross-sectoral policies. These countries and regions together contribute more than two thirds of global GHG emissions. The paper finds that policies that are nationally driven and that have multiple objectives, including climate-change mitigation, have been widely applied for decades in both developing countries and industrialised countries. Many of these policies have a long history, and adjustments have taken place based on experience and cost effectiveness concerns. Various energy and climate-change policy goals have worked together in these countries, and in practice a mix of policies reflecting specific priorities and contexts have been pursued. In this way, climate-change mitigation has been aligned with other policy objectives and integrated into broader policy packages, though in many cases specific attention has not been given to the achievement of large GHG emission reductions. Based on these experiences with policy implementation, the paper highlights a number of key coordination and design issues that are pertinent to the successful joint implementation of several energy and climate-change policy goals.     

Non-CO2 gaseous emissions from upstream oil and gas operations in Nigeria

The Nigerian crude oil is formed in association with natural gas. The associated gas has mostly been flared in the process of crude oil exploitation. Current estimates are that approximately 70% of produced natural gas is flared. Carbon monoxide, volatile organic compounds and nitrogen oxides emissions from oil and gas exploitation activities are presented for major combustion activities: gas flares and power generation at oil fields for oil and gas gathering systems. The emissions rates and combustion efficiency for a newly tested modified flaring system with enhanced air supply and liquid aspiration system for the atomization of the condensate phases of the flared gas was found to be capable of improving combustion efficiency by 20% or more in comparison with the conventional flare-type currently in vogue. Flare emissions for CO and NO_x are an order of magnitude higher than other sources in the oil and gas sector.     

PIXE characterization of PM10 and PM2.5 particulates sizes collected in Ikoyi Lagos,Nigeria

Ambient concentrations of PM₁₀ (x?≤?10?µm) and PM_2.5 (x?≤?2.5?µm) particulate fractions collected from Ikoyi Lagos, Nigeria, as well as their elemental compositions are presented in this study. Both size-segregated fractions were collected using a double staged ‘Gent’ stack filter unit sampler. Elemental characterizations of dust laden filters were carried out using proton-induced X-ray emission (PIXE) technique. Twenty-two elements (Si, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Pb, Br, Rb, Sr, Zr, Ag, Cd, and Ta) were detected as well as their concentrations and correlations were determined for both particulate size fractions. Their correlation matrix result indicates that some of the trace elements detected could have common source origins or similar chemical properties. The results were similar to the levels observed in moderately polluted urban areas and there is need for source identification and apportionment using receptor models in future studies.     

A Nationwide Assessment of the Biodiversity Value of Uganda's Important Bird Areas Network

Abstract:  BirdLife International's Important Bird Areas (IBA) program is the most developed global system for identifying sites of conservation priority. There have been few assessments, however, of the conservation value of IBAs for nonavian taxa. We combined past data with extensive new survey results for Uganda's IBAs in the most comprehensive assessment to date of the wider biodiversity value of a tropical country's IBA network. The combined data set included more than 35,000 site × species records for birds, butterflies, and woody plants at 86 Ugandan sites (23,400 km²), including 29 of the country's 30 IBAs, with data on additional taxa for many sites. Uganda's IBAs contained at least 70% of the country's butterfly and woody plant species, 86% of its dragonflies and 97% of its birds. They also included 21 of Uganda's 22 major vegetation types. For butterflies, dragonflies, and some families of plants assessed, species of high conservation concern were well represented (less so for the latter). The IBAs successfully represented wider biodiversity largely because many have distinctive avifaunas and, as shown by high cross-taxon congruence in complementarity, such sites tended to be distinctive for other groups too. Cross-taxon congruence in overall species richness was weaker and mainly associated with differences in site size. When compared with alternative sets of sites selected using complementarity-based, area-based, or random site-selection algorithms, the IBA network was efficient in terms of the number of sites required to represent species but inefficient in terms of total area. This was mainly because IBA selection considers factors other than area, however, which probably improves both the cost-effectiveness of the network and the persistence of represented species.     

Emission inventory for Nigeria with CAREAIR

CAREAIR is the abbreviation for Computer aided Analysis of Reduction strategies for Emissions and ambient AIR pollution. It is a modelling-system for air pollution analyses including a flexible emission model developed at the IER. The PC-based version of the system is especially designed for applications in so-called 3rd-world countries, but in fact it can be used for any country. A modeling database for many emission relevant processes and related emission factors is part of it. This paper first gives a short overview on the capabilities of CAREAIR and secondly presents part of the emission inventory for Nigeria, which has been elaborated using CAREAIR during a cooperation between the University of Stuttgart (FRG) and the Obafemi Awolowo University of Ile-Ife (Nigeria). In particular estimates of the yearly emissions of total Hydrocarbons (VOC = Volatile Organic Compounds), divided into CH₄ (Methane) and NMVOC (Non-Methane-VOC), NO_x (Nitrogen Oxides), N₂O (Nitrous Oxide), CO₂ (Carbon Dioxide) and CO (Carbon Monoxide) emissions in Nigeria 1989 are given.     

The Seasonal Variation of the Concentrations of Ozone, Sulfur Dioxide, and Nitrogen Oxides in Two Nigerian Cities

A combination of multivariate statistical methods including factor analysis, principal component analysis, principal component regression, and multiple linear regression (MLR) were employed to evaluate the influence of seasons on the concentrations of ozone, sulfur (IV) oxide, and oxides of nitrogen in ambient air of Nigerian cities of Lagos and Ilorin. The former city is located in the coastal area, and it is highly congested with a high intensity of marine, vehicular, and industrial activities, and the latter city is a medium size town, located in the central guinea savannah zone of Nigeria. Samples were collected using a high-volume sampler from near the ground at various sites of diverse human and industrial activities, during wet and dry seasons from 2003 to 2006. The PCA reveals three distinct groupings during the day for all data, which is a reflection of different factors contributing to the atmospheric chemistry of these cities. The predicted ozone concentration values by MLR agree fairly well with the measured data. The dependence of ozone on meteorological parameters including relative humidity, air temperature, and sun exposure and the precursor pollutants depends on weather and the anthropogenic activities. The results for the two cities indicate that reduction in the level of NO₂ is accompanied by an increase in the level of ozone, suggesting the interconversion between the two via photochemical activity.     

Atmospheric particulate matter in Nigerian megacities

The paucity of data on air pollution indices in Nigeria prompted us to commence a national screening exercise regarding particulate matter loads. Six potential megacities (Aba, Abuja, Lagos, Kano, Maiduguri, and Port-Harcourt) representing the six geographical zones in Nigeria were chosen for the study. Sampling was achieved using a ‘Gent’ stacked filter unit sampler capable of collecting fractions of particulate matter with sizes of <10-μm and <2.5-μm simultaneously. The mean values for PM₁₀ are 550, 35, 87, 340, 246 and 130 μg m^?3 while for PM_2.5 the mean values are 100, 14, 25, 67, 20 and 30 μg m^?3 respectively for Aba, Abuja, Lagos, Kano, Maiduguri, and Port-Harcourt. Except for Abuja, the daily PM₁₀ mass loads exceeded the World Health Organization (WHO) guidelines daily limit where as the PM_2.5 values were within the WHO guideline limit. Their correlation matrix result indicates that some PM_2.5 fractions mass fractions were strongly correlated than the PM₁₀ fractions probably due to their long range transport potentials. Further work is in progress to determine the elemental profiles of both particulate fractions collected.     

Airborne fine particulate matter (PM2.5) at industrial,high- and low-density residential sites in a Nigerian megacity

Abstract

Airborne particulate matter PM_2.5 was collected in an industrial, a low-density, and a high-density residential area of Lagos from December 2010 to November 2011, and elemental composition was determined by proton-induced X-ray emission. Across the months, mass concentrations ranged from 13 to 237?µg?m^?3, exceeding the World Health Organization guideline value of 10?µg?m^?3. Data on 24 elements were obtained, with maximum values during Harmattan season months; source identification and apportionment studies by positive matrix factorization suggested that petroleum oil combustion (70%) was the major source of PM_2.5 and could pose a great hazard to Lagos receptors.