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This paper examined the impact of particulate matter (PM) along the Ibadan-Ilorin highway of Nigeria. The study was conducted in Ogbomoso-section of Ibadan-Ilorin highway of Nigeria at three different locations for the wet and dry seasons. The GT-321 particle counter was used to measure the PM. It has five selectable size ranges of 0.3, 0.5, 1.0, 2.0, and 5.0 micron. The result of investigation showed that PM0.3 had highest percentage concentration values (87 – 96%) in all the selected location and in both seasons. The results of the research work showed that selected location and season had impact on the emission rate of the particle. All the selected sizes of PM had values more than ISO classes 1 -7 maximum concentrations limit. The study concludes that transport-related pollution is indeed significant within the study area with possible severe health consequences.

Indoor air measurements of aerosols emitted from the use of household spray products are expensive and time-consuming. An analytical model was developed and incorporated into a graphical user inter...

This study investigates kinetics and Adaptive Neuro-Fuzzy Modeling (ANFM) of river turbid water coagulation-flocculation (CF) process using mango kernel coagulant (MKC). CF experiments were...

This study is aimed at developing a neuro-fuzzy model with the Matlab Graphical User Interface (GUI) for calculating the biocoagulant quantity needed for turbid water clarification. A neuro-fuzzy network (NFN) was developed for three different levels (low, medium and high) of turbid water. Experimental turbid water bioclarification data were used, in the Matlab environment through a sub-clustering neuro-fuzzy function, for modelling NFN. The network consisted of four inputs (untreated water turbidity, untreated water pH, settling time as well as treated water turbidity) and Mango Kernel Coagulant (MKC) dosage as the output variable. The best NFN architectures that produced minimum percentage error were considered for biocoagulant dosage calculator GUI development and implementation. The experimental data and results obtained from the NFN-GUI calculator were compared; and the prediction of the dosage has Root Mean Square Error (RMSE) as well as correlation coefficient ranges of 0.01–0.10 and 0.93–0.99 respectively. The high correlation coefficient found in this study indicates that the NFN-GUI calculator is a perfect match with the traditional jar-test calculator. Therefore, the Matlab-based calculator template is able to predict the biocoagulant quantity needed in a community water bioclarification treatment unit.

This study is to determine in-vehicle and pedestrian exposure to carbon monoxide (CO) and volatile organic compounds (VOCs) in six roadways in Lagos mega city. Measurements were made twice a day for two weeks for four major modes of transportation in the city using the MultiRae ambient gas monitor. The levels of CO measured were 4.40–39.78 ppm while that of VOCs were 0.00–0.39 ppm. Highest average CO and VOCs concentrations were obtained inside car during morning commuting periods. These average concentrations were found to be statistically significant when compared with other three transportation modes studied. The average concentrations of the pollutants in the morning were statistically similar to average concentration in the afternoon as Student's t-test indicated no statistical significant difference (p > 0.05). This study revealed that car commuters are exposed to higher concentrations of CO and VOCs than bus and BRT commuters with pedestrians having the lowest exposure to the pollutants.

Open burning of scrap (bicycle, motorcycle, car and truck) tyres (OBST) was simulated in the laboratory to investigate their impact on the ambient air quality. The tyre samples were burnt in combustion chamber, and gaseous pollutants (CO, NO2 and SO2) emitted were quantified, while concentrations and elemental compositions of emitted total suspended particulates (TSP) were determined. Emission level of SO2 from all the tyre samples exceeded USEPA allowable (156.74 µg/m3) limit. CO due to car and truck tyres exceeded USEPA allowable (10,285.71 µg/m3) limit, while NO2 concentration was below the allowable limit (56.33 µg/m3) only in bicycle tyre. 25% of all the gaseous pollutants emitted are within the Air Quality Index range of 101–150. TSP concentrations from all the tyre samples were higher than the Federal Ministry of Environment standard (250 µg/m3) for ambient TSP. There is strong correlation (R) of 0.885, 0.949 and 0.802 among all the gaseous (CO/NO2, CO/SO2 and NO2/SO2) pollutants, respectively, while the highest (0.999) and lowest (0.079) positive correlations were observed between Mg and Mn as well as Cd and Zn, respectively. The results of this study show that OBST emits hazardous pollutants, which pose serious threat to human health and environment.

Purpose The introduction of mobile telecommunication services in Nigeria led to the development of base transceiver stations (BTS) across the country. Inadequate power supply from the national grid has led to massive use of diesel-fueled back-up generators (BUGs). The purpose of this paper is to attempt to quantify and inform relevant stakeholders about air quality implications of BTS BUGs. Design/methodology/approach Seven major telecommunication network operators were identified. Emission factor approach was used to estimate the quantity of important air pollutants such as NOx, CO, SO2, PM10, PM2.5, PAH and TVOC that are emitted from the use of the BUGs based on fuel consumption rate and generators’ capacity. Fuel-based emission inventory and emission factor from the United States Environmental Protection Agency AP-42 and National Pollution Inventory were used to estimate pollutants emission from diesel-powered generators used in the BTS sites and amount of diesel consumed. Land distribution and per capita dose of the estimated pollutants load were calculated. Findings The study showed that the deployment of BUGs will lead to increase emissions of these air pollutants. The states that are most affected are Lagos, Kano and Oyo, Katsina and Akwa Ibom states with respective total air pollutants contribution of 9,539.61, 9,445.34, 8,276.46, 7,805.14 and 7,220.70 tonnes/yr. Originality/value This study has estimated pollutant emissions from the use of diesel-fueled BUGs in mobile telecommunications BTS sites in Nigeria. The data obtained could assist in policy making.

Power sector in Nigeria is undergoing structural reforms aimed at improving and expanding the current generation capacity, using thermal power plants. Ground level concentrations of air pollutants emitted from natural gas-powered thermal power plants were estimated using the American Meteorological Society-Environmental Protection Agency Regulatory Model (AERMOD). The average 24-h ground level concentrations of CO, NOx, SO2, particulate matter (PM), and volatile organic compounds (VOCs) were 31.88–72.79; 61.33–104; 0.61–3.91; 0.21–1.52; and 0.19–1.09 µg/m3, respectively. There is need for continuous monitoring of ground level concentration of pollutants around the thermal power plants to guarantee the safety of the environment in the host communities.

The contribution of SO2 emissions from the consumption of petroleum products to Nigerian airshed has been of great concern over the years because of the resulting adverse environmental and health effects. It is in the light of this that air emissions of SO2 from gasoline and diesel consumed in the Southwestern States of Nigeria were estimated in this study. Lagos state being the highest consumer of gasoline and diesel in Southwestern Nigeria emitted the highest quantity.

The understanding of aerosol deposition in the indoor environment is relevant for assessing the exposure of occupants. This study investigates the effects of microclimatic parameters on the deposition rates of aerosols emanating from the use of household spray products in indoor environment. A three–factor factorial design was used to study the effects of interactions of air temperature, relative humidity and Air Exchange Rate (AER) on the deposition rate of particulate matter (PM). The highest deposition rate of 0.3μm particles (PM0.3) was 627.8h–1 when the relative humidity, temperature and AER were 40%, 40°C, and 12 h–1, respectively while the highest deposition rate of 5.0μm particles (PM5.0) was 709.20h–1 when the relative humidity, temperature and AER were 70%, 25 °C, and 12h–1, respectively. Regression analysis showed that air temperature and air exchange rate had significant effects on the deposition of PM0.3, while relative humidity and air exchange rate had significant effects on the deposition of PM5.0 at p

This study employed turbidimetric method using a UV/VIS spectrophotometer to determine the total sulfur levels of refined petroleum products in Southwestern Nigeria. The sulfur concentrations in the analyzed fuel samples were 0.0019–0.0178 wt% and 0.027–0.169 wt% for gasoline and diesel, respectively. Sulfur levels in the selected samples were below the Nigerian standard for gasoline and diesel while 89.9% of the samples exceeded the U.S. Environmental Protection Agency standard. The turbidimetric method showed better performance than the gravimetric method. The results gave insight into the adverse environmental impact the nonuniform quality of fuels imported could pose to the country.

Deleterious impact of lead from the use of motor fuels is of major concern. Lead levels of gasoline and diesel samples from States in Southwestern Nigeria were analysed by Atomic Absorption Spectrometer, according to the standard ASTM D3237-97 method. Lead concentrations ranged from 0.491–1.903 mg/L for gasoline and 2.301–10.97 mg/L for diesel. Estimated lead levels in gasoline were below the Department of Petroleum Resources (DPR) Nigeria limit of 3.37 mg/l. Percentage lead contributions from gasoline and diesel fuel consumption were minimal due to various fuel lead-level regulations that have been established over the years.

PurposeThe aim of this paper is to provide basic information on the types of particulate cyclones separators used in the chemical and process industries, their principles of operation and factors affecting their performance.Design/methodology/approachA general review of the types of particle cleaning cyclones used in the chemical and process industries was carried out and the principles guiding their operation and performance discussed. Information which could aid the choice of cyclone for new applications is also discussed.FindingsIt was concluded that the choice of cyclone for any application is associated with a trade‐off between two contrasting performance indicators (collection efficiency and pressure drop). Adequate and accurate data gathering is essential right from the design stage for smooth operation of cyclone.Originality/valueThe paper highlights the general principle of operation of cyclone separators and the factors that affect their performance.

This study examined the ambient levels of criteria air pollutants in the indoor and outdoor environment of a typical hospital facility. Ambient concentration of the criteria pollutants was monitored at nine sampling locations using the ToxiRAE gas monitors both in the rainy and dry seasons. The results showed that the overall 24-h concentrations for CO and NH3 were 0.18 ± 0.19 and 0.11 ± 0.13 ppm, respectively, for dry season. During the wet season, the extrapolated 24-h concentrations ranged 0.09–1.09 ppm for CO, 0.04 ± 0.08 ppm for NH3 while NO and NO2 had 0.03–0.21 ppm and 0–0.06 ppm, respectively. The result of the study shows that the 24-h NH3 concentration of 0.44 ppm recorded at S5 during dry season breached the National Air Quality Standards of the Federal Ministry of Environment Standard, Nigeria. Similarly, NO and NO2 levels were higher than other gaseous parameters measured in all the sampling locations during the wet season. This study establishes that human activities may have deleterious effect on air quality in the hospital airshed.

Open burning of scrap tyres (OBST) has been identified as a key source of gaseous pollutants. However, OBST has been widely and indiscriminately practiced in Nigerian communities with less attention to its environmental impacts. Gaseous pollutants (CO, NO2 and SO2) emitted from OBST were investigated. In this study, 20 types of tyres representing five from each of bicycle, motorcycle, car and truck category were considered. The emission levels of CO, NO2 and SO2 in the tyre smoke were quantified by means of modules in validated Testo 350 XL flue gas analyser. The toxicity potential (TP) levels of CO, NO2 and SO2 ranged from 0.32-1.12, 0.20-4.83 and 0.29-1.76, respectively. Out of all the gaseous pollutants emitted, 25% is within the air quality index range of 101-150. An assessment of the toxicity potential levels of these hazardous gaseous pollutants suggests that OBST may pose serious threat to human health and environment.

On October 12, 2005, a mysterious fog engulfed some parts of Lagos, the cause of which is yet to be identified. As part of the on-going scientific attempts to identify its cause, this article examines the contribution of anthropogenic combustion processes to oxides of nitrogen (NOx), carbon monoxide (CO), sulphur dioxide (SO2), and particulate matter (PM10) in Lagos. On the average, predicted emissions are: NOx, 3.43 × 104; CO, 1.46 × 106; SO2, 1.24 × 103; and PM10, 7.84 × 1013 ton/annum. Vehicular emissions from road transportation is an identified major source of criteria air pollutants in the city because combustion of gasoline in buses generated about 32% and 77% of the predicted NOx and CO emissions, respectively. Similarly, significant portions of predicted SO2 emissions (57%) come from low pour fuel oil (LPFO) combustion. The highest emission of PM10 from wood fuel combustion, which is 83%, raises some concern due to its potential impact on indoor air quality. Some control measures and ide...

Morphological studies of the leaves of ten species in the family Euphorbiaceae collected from three different locations with different pollution levels in Southwestern Nigeria were carried out in order to establish the effect of air pollution on these species. The study was carried out in both dry and wet seasons. Climatic data and pollutants concentration levels of the study sites were determined. Leaf area of all the species was measured using an established nondestructive method while petiole length was determined using metric ruler. The result showed that most species showed significant reductions (p

Vehicular emissions portend high risk to human health especially to inhabitants of highway environment. However, there is paucity of information on the inventory of air pollutants on Nigerian highways. Therefore, this study aimed at estimating the ground level concentrations of emissions associated with road traffic in the Ogbomoso-section of Ibadan-Ilorin highway. Three sampling locations (Idi-oro, General and Aroje) were selected within the Ogbomoso section of Ibadan-Ilorin highway for this study. Data collections on criteria air pollutants [carbon monoxide (CO), nitrogen monoxide (NO) and sulphur dioxide (SO2)] and total suspended particle (TSP) were made within dry and wet seasons. The results of predicted concentrations of CO, NO, SO2 and TSP ranged between 0.59-352.60, 0.28-213.40, 0.04-33.40 and 0.02-14.20 µg/m3, respectively. All the predicted concentration values of selected pollutants meet-up with the regulatory standards. This study has provided baseline inventory for criteria air pollutants in the Ogbomoso-section of Ibadan-Ilorin highway.