Occurrence of polycyclic aromatic hydrocarbons in Nigeria’s environment: A review

The occurrence and levels of polycyclic aromatic hydrocarbons (PAHs) in Nigeria’s environ�ment were reviewed in this study. A survey of the literature showed that a considerable number of reports exist on the presence of PAHs in Nigerian soil, water and sediments. Information on the presence of PAHs in the country’s air- shed exists but in very limited number. The sources of PAHs are ubiquitous and their concentrations in the country’s en�vironment are above the permissible limit set for the pollutant by European Union, the United Kingdom, China and the World Health Organization in most instances. There is practically an absence of regulatory standards for PAHs in ambient air and soil in Nige�ria. More studies on source apportionment are needed to be able to ascertain the sources of PAHs and their respective contributions to ambient air concentration. Considering the ubiquitous sources of PAHs, their reported elevated levels in the few publications avail�able in the literature and their carcinogenic and mutagenic tendencies, there is the need for policy makers to drive research on PAHs in Nigeria with a view to setting regulatory standards for the individual carcinogenic PAHs as well as the total PAHs concentrations allowable in different media. Due to the low level of public awareness on the risks and hazards associated with an exposure to PAHs, there is a need to deepen advocacies on polycyclic aromatic hydrocarbons and their public health concerns

Fuel-Briquetting for Sustainable Development in Developing Countries-A Review

This review covered recent research products on fuel-briquette with emphasis on its production technologies and physical characteristics involving shapes, volumes, resiliencies, and mechanical compressive strengths; combustion properties such as high heating values, volatile matters, moisture contents, ash contents and fixed carbon; chemical analyses for the content of components such as nitrogen, hydrogen, sulfur, oxygen and carbon; emission characterization such as and economic potentials. This review provides opportunities for investors, researchers, governments, individuals, and industries, especially on alternative forms of energy that could be harnessed from waste management and the conservation of forests and its optimal management of carbonaceous wastes and sustainable energy production. Other prominent merits of using fuel-briquettes are the conserving of time in cooking in homes and heating in industries and employment opportunities

DISPERSION MODELLING OF PARTICULATE EMISSION FROM OFF-GRID DIESEL ENGINE ELECTRIC POWER GENERATORS

Emission inventories and ISC-Aermod dispersion modeling tool were used to investigate the impacts of particulate matter (PM) emission from off-grid electric power generators used by a textile factory on ambient air quality (AAQ) of the immediate and distant environment of the plant. Information on diesel consumption obtained from the factory was combined with emission factor of diesel powered generators to obtain the emission rates of PM. The emission rates, meteorological parameters, terrain grid and output pathways were inputed into the ISC-Aermod dispersion modeling tool to obtain the ground level concentrations (GLC) of PM. The maximum GLCs were compared with AAQ limit of 250 μg/m3 set for PM by Nigeria’s Federal Ministry of Environment to establish their impacts. Results showed that worst case scenario (WCS) gave PM concentrations of 1.4 – 17.8 μg/m3 and 0.1 – 6.8 μg/m3 for 1-hr and 24-hrs averaging period respectively. The predicted impact using the WCS showed that the ambient PM of the host air shed changed by 0.1 - 1.2% of FMENV standard. It was concluded that emissions from factory would not significantly affect the ambient PM of the host air shed

A Short Review on Land/Soil Pollution: The Pollutants and the Treatment Techniques

Land is an integral part of the ecosystem that supports human activities. The pollution of soil has been a major concern to conservationist and environmentalist globally. Contaminated land is affecting crop production and posing threats to human health. The choice of a suitable separation technique in the removal of pollutants from affected soils depends on the kind of pollutants, concentration and location characteristics. This review examines the different sources of soil pollution and available methods for the treatment of polluted soil

Investigation of Some Gaseous and Trace Metal Emissions With Their Emission Factors From Various Brands of Mosquito Coils Used in Nigeria

Mosquito coils of various brands are frequently burnt in indoor environments to drive away mosquitoes—the vector for malaria parasite in regions where the disease is endemic. Emissions from the coils could be a source of indoor air pollution. In this study, various brands of mosquito coils obtained from retail shops in Lagos, Nigeria were burnt in an environmental test box with a view to characterizing carbon monoxide (CO), nitric oxide (NO), and nitrogen dioxide (NO2) in the gaseous emissions as well as elemental concentrations of the ash. Emission characterization achieved with the RAS1700 bio-gas analyzer while AAS was adopted for elemental analysis of the mosquito coil ashes. The emission factor of CO, NO and NO2 from the coil samples ranged between 0.00138 to 0.26277 μg/m3, 0.0002 to 0.00454 μg/m3, and 0.000074 to 0.00714 μg/m3, respectively. These values were found to be lower than permissible indoor levels recommended by NIOSH. The range of concentrations of Pb, Zn, Cd, Cr, Cu, As, Hg, Fe in the coil ashes from all the brands were 0.02 to 0.04 mg/g, 0.011 to 0.02 mg/g, 0.001 to 0.003 mg/g, 0.004 to 0.008 mg/g, 0.004 to 0.006 mg/g, 0.0001 to 0.0004 mg/g, 0.001 to 0.003 mg/g, and 0.124 to 0.14 mg/g, respectively. Although, the concentrations of the pollutants obtained in this study are within the recommended limits, prolong exposure could trigger chronic disease conditions. Adequate ventilation of indoor environments or utilization of mosquito nets in place of coils could be considere

Impact of Trace Gaseous Emission from Fuelwood Species on Ground Level Air Quality

Nigeria’s energy supply in the form of electricity has been erratic and unreliable in recent time that people now depend on their own power generation in order to meet demands. Thus majority of the populace have to depend on traditional fuelwood for cooking without knowing the impacts of air emissions from it. This study estimated the ground-level concentrations of the air pollutants emitted from the fuelwoods using the American Meteorological Society-Environmental Protection Agency Regulatory Model (AERMOD). The maximum 24 h averaging ground-level concentrations were 6.378–87.319, 1.546–75.164, 0.079–2.759, and 0–0.164 μg/m3, respectively for CO, HC, NO, and SO2. With this all stakeholders will be properly guided on the usage of fuelwood with minimal negative impact

Identification of the woody biomasses in Southwest, Nigeria as potential energy feedstocks in thermal power plants for air pollution control

This study identified one hundred samples of woody biomasses in the southwest, Nigerian. The woody biomass samples identified were collected from different saw mills, farms and kitchens in Osun State, Nigeria. The identification of the woody biomass samples was done using literature materials and at a herbarium in the Botany Department, Obafemi Awolowo University, Nigeria, using the vegetative parts of their trees. The identification was carried out to know the numerical availability, the family or English names, the common names and the botanical names of the southwest Nigeria woody biomasses. From the findings, 100 samples of the woody biomasses were identified of 39 families and classes of hard woody biomasses and soft woody biomasses out of which only two are soft and rest are hard. It was discovered that Southwest, Nigeria has the capacity to embark on the massive production of these woody biomasses identified due to her land mass of 77,818 km2 comprising 85 forests. In conclusion, serious investment in the propagation of these energy crops would lead to the production of woody masses to serve as feedstocks in thermal power plants for sustainability in power supply, air pollution control and employment opportunities

Cement industry – Associated emissions, environmental issues and measures for the control of the emissions

The cement industry though the backbone of modern construction and civilization is associated with the emission of diverse atmospheric pollutants with numerous attendant effects on the balance of ecosystem, human and environmental health, and the global climate in general. Despite the huge advantages derivable from the industry, exploitation and processing of cement must be done in a sustainable manner to prevent irreversible damage to human, animal and vegetation health as well as the environment. Research papers were reviewed from different databases like ScienceDirect, ResearchGate, Google scholar, and Scopus the chief air pollutants are the inorganic gaseous emissions (carbon dioxide (CO2), carbon monoxide (CO), oxides of nitrogen (NOx), oxides of sulphur SO2), particulates of various size ranges and elemental emissions. The present study carries out holistic review of the cement production process with a view to identifying the principal air pollutants, sources and associated environmental issues. The study also reviews the pollution control measures currently in use and calls for a concerted effort from researchers, industry operators and regulators at working to reduce emissions with a view to upholding environmental sustainability

Impacts of heavy duty truck emissions on the vertical distributions of soil polycyclic aromatic hydrocarbons at a big haulage vehicle park

Nigeria relies heavily on heavy duty haulage vehicles to convey commodities from one end of the nation to the other, owing to the decades-long collapse of the rail transportation infrastructure. This is resulting in settings with very high concentrations of the trucks on the country’s key roads. Diesel engine exhausts have long been recognized to be detrimental to human health. The concentrations of polycyclic aromatic hydrocarbons (PAHs) in the top and bottom soil samples from an extensive haulage vehicle stop located at Ogere, a roadside town along the ever busy Lagos-Ibadan highway were investigated. Soil samples taken at depths of 0–15 cm and 15–30 cm were subjected gas-chromatographic/mass spectrometer analysis. The Ʃ priority PAHs in the top and bottom soils at four sampling locations ranged between 16.4 and 32.0 mg/kg and 18.6–26.6 mg/kg respectively. The corresponding Ʃ carcinogenic PAHs for top and bottom soils ranged between 9.2 and 17.4 mg/kg and 8.7–12.0 mg/kg respectively. The concentrations of PAHs obtained in this study clearly exceeded the permissible limits set for soil PAHs in most developed nations of the world. The diagnostic ratio attributed the observed PAHs to diesel emissions. The study concluded that the emissions from the trucks at the haulage vehicle stop have tremendous impact on the soil PAH concentrations