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

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

A REVIEW ON TREATMENT METHODS OF USED LUBRICATING OIL

Disposing used lubricating oil (ULO) through local means has been found to lead to air, land and water pollution. This pollution lowers the lifespan of inhabitants due to spread of diseases. Treatment of used oil is one of the easiest way to avoid pollution as observed in literatures. Aside preventing pollution, another advantage is majorly turning waste to wealth. In this paper, an indebt review was done on the various methods for treating used lubricating oil. The advantages and shortcomings of each method were highlighted for further study

Selecting the Most Appropriate Model for Rheological Characterization of Synthetic Based Drilling Mud

Several mathematical models used in describing the rheology of non-Newtonian fluids includes but not limited to the following; The Power Law model, the Bingham Plastic Model, the Hershel-Buckley Model and the Casson Model. Selection of the best rheological model that accurately represent the shear stress-shear rate analysis is sine qua non to achieving correct results for pressure drops and hydraulic calculations. Hence, in this study, in an effort to determining the best rheological model that accurately represent the rheology of Synthetic based Muds (SBMs), three different Synthetic based Fluids were used to form different Synthetic based Muds with the same composition throughout. These fluids are; Refined Bleached and Deodorized Coconut Oil (RBDCO), Methanol Trans esterified Palm Kernel Oil (TRANSPKO) and Inter Esterified Palm Kernel Oil(INTERPKO). The rheological properties of these drilling muds were measured by using an automated 8-speed viscometer model 800.The dial readings of the viscometer were then converted to stresses by applying standard conversion factors and different non-Newtonian Models were used in computing the stress values. In order to measure the degree of deviation of each model from the measured stress, two statistical methods were employed. These are; the Absolute Average Percentage Error

Selecting the Most Appropriate Model for Rheological Characterization of Synthetic Based Drilling Mud

Several mathematical models used in describing the rheology of non-Newtonian fluids includes but not limited to the following; The Power Law model, the Bingham Plastic Model, the Hershel-Buckley Model and the Casson Model. Selection of the best rheological model that accurately represent the shear stress-shear rate analysis is sine qua non to achieving correct results for pressure drops and hydraulic calculations. Hence, in this study, in an effort to determining the best rheological model that accurately represent the rheology of Synthetic based Muds (SBMs), three different Synthetic based Fluids were used to form different Synthetic based Muds with the same composition throughout. These fluids are; Refined Bleached and Deodorized Coconut Oil (RBDCO), Methanol Trans esterified Palm Kernel Oil (TRANSPKO) and Inter Esterified Palm Kernel Oil(INTERPKO). The rheological properties of these drilling muds were measured by using an automated 8-speed viscometer model 800.The dial readings of the viscometer were then converted to stresses by applying standard conversion factors and different non-Newtonian Models were used in computing the stress values. In order to measure the degree of deviation of each model from the measured stress, two statistical methods were employed. These are; the Absolute Average Percentage Error

Energy Status, Energy Mix and Renewable Energy Potentials of Nigeria

The review looked at Nigeria's energy status, energy mix, and renewable energy potentials in order to provide information on the opportunities in the country's energy sector that could be taken advantage of, by people, researchers, investors, businesses, and governments. This is critical in light of the existing energy supply gaps hence the need for sustainable energy production

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

Assessment of Indoor Levels of Carbon Monoxide Emission from Smoldering Mosquito Coils Used in Nigeria

Mosquito coils are commonly burnt in indoor environments to drive away mosquitoes which are vectors for malaria parasites. The levels of carbon monoxide (CO) emitted and human health implications during smoldering of 5 different brands of mosquito coils commonly used in Nigeria were investigated in 4 microenvironments of different sizes. The experiments were done by taking a scenario of a sleeping arrangement and the farthest distance between the coil burning and an arbitrary bed position in 4 different bedrooms of different sizes in poor ventilation condition of closed doors and windows. With monitoring device, ALTAIR 5X portable gas analyzer, at the position of the bed, measurements were taking at 2 minutes interval from start to the end of burning of each coil. The emission profile was determined by making concentration-time plots of CO emission to determine its levels from the burning of each brand of the mosquito coils in each microenvironment. From the emission profile, coils A, C, and D showed that CO levels exceeded Nigeria’s Federal Ministry of Environment (FMEnv) and the World Health Organization (WHO) statutory limit of 9.0 ppm for indoor environments in each of the microenvironments between 3 and 7 hours after the burning commenced. It was concluded that the CO concentrations from smoldering mosquito coils is a function of the size of the microenvironment in which it is used. It was recommended that the size of a microenvironment be determined for consumption of a mosquito coil before it is released into the marke

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