Impact of elemental composition of particulate matter in the airshed of a University Farm on the local air quality.

The impact of particulate matter on the ambient air quality of Landmark University Farm was assessed using deposition fluxes of Trace elements (TEs) in the airshed of the farm. Deposition gauges were employed to collect both dry and wet deposition samples of particulate matter between 2018 and 2019. Elemental compositions of particulates collected during the sampling period were analyzed using Energy Dispersive X-ray Fluorescence Spectroscopy (ED-XRF). The deposition fluxes of crustal and anthropogenic trace elements were also determined using standard methods. Results showed that in dry season, iron has the highest mean concentration (3283.61 mg/kg), while chromium has the lowest (0.023 mg/kg). On the other hand, in wet season, silicon and nickel have the highest and lowest mean concentrations of 159.34 mg/kg and 0.01 mg/kg respectively. Although the concentrations of these metals were higher in the dry season than wet season, there was no statistical significant difference between the mean concentrations of the elements measured in each season of the year (p > 0.05). The compositions of some of the elements in the particulate matters were found to be far above the recommended exposure limits prescribed by OSHA. The study concluded that the elemental composition of particulate matter in the airshed of the University Farm adversely impacts the ambient air quality of the Communit

In-vehicle and pedestrian exposure to carbon monoxide and volatile organic compounds in a mega city

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 N 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

Spatial Dispersion Modelling of Air Emissions from a Farm Using Gaussian Model

Agricultural activities may cause significant air pollution at the local, regional, and global scales due to the uncontrolled release of pollutants into the environment. This study therefore provided model-based spatial estimates of ground-level concentrations of air emissions from Landmark University Farm. The emission inventory and meteorological parameters of the farm were used to execute a Gaussian dispersion model over a distance of 2 km. Elevated ground-level concentrations were recorded, which continued to decrease as the distances increased. These concentrations exceeded threshold limits stipulated by National Ambient Air Quality Standard. The study concluded that high levels of air emissions obtained in this study are indications of tendencies for possible violation of permissible limits at locations not too far from the University Farm

Valorization of Pennisetum purpureum (Elephant grass) and piggery manure for energy generation

This study investigated the biogas production potential of Pennisetum purpureum (Elephant grass) (El-g) codigested with piggery manure (PM) under mesophilic condition in order to combat the menace of weed in cropping systems as well as pollution problems emanating from disposal of PM. Prior to anaerobic digestion (AD), El-g was subjected to a combination of mechanical, thermal and alkaline pretreatments. Using cattle rumen content as inoculum, the pretreated El-g was anaerobically co-digested with PM while the raw El-g was also codigested with PM and served as control experiment. The physicochemical characteristics of feedstock were evaluated before and after the digestion period using standard methods. The initial high concentrations of chemical oxygen demand (COD) reduced significantly after digestion indicating efficiency of the digestion process. Also, there were reductions in concentrations of calcium and other parameter needed for microbial growth after the digestion which indicated their utilization by microbes to generate biogas. Biogas production began on the 5th and 7th days and was progressive until 30th and 24th days in both digestions after which a decline was observed until the end of the experiment. For the digestion period of 37 days, the total biogas recorded from the pretreated and untreated experiments were 409.5 and 184.1 m3 CH4/kg VS with average of 11.07 and 4.98 m3 CH4/kg VS/day respectively. The study concluded that co-digestion with piggery dung enhanced the biogas producing capacity of El-g hence advocated

Personal exposures to particulate matter in various modes of transport in Lagos city, Nigeria

Urban air pollution continues to be a major problem in Nigerian cities. Most studies of air pollution in Nigeria have concentrated on the background air quality and its effects on people outside vehicles. However, it has been suggested that in-vehicle pollution is often worse than pollution outside the vehicle. This study focuses on personal exposures to PM10 and PM2.5 in various modes of transportation in Lagos city. Six roadways which are representative of commercial, industrial, and residential areas of the city were selected. Measurements were made inside four major modes of transportation in the city: cars, buses, Bus Rapid Transit (BRT), and walking for PM10 and PM2.5. Measurements were done for each mode twice a day (morning and afternoon) for 12 days. The highest average PM10 and PM2.5 concentrations were measured for pedestrian (476.35 and 216.60 μg/m3, respectively) during rush hours. The result showed that pedestrians were found to be exposed to the highest average PM10 and PM2.5 concentrations, while commuters in cars, BRT and buses were exposed to respective decreasing concentrations of PM10. Similarly, commuters in BRT were exposed to the lowest concentrations of PM2.5 regardless of time of day. The results obtained were much higher than the results for London but comparable to Mexico city and Taiwan’s results. This study has provided information that can help commuters to choose appropriate travel behavior that can minimize their exposure to particulate matter

Potential for cleaner energy recovery and electricity generation from abattoir wastes in Nigeria

Energy recovery and electricity generation from abattoir wastes was investigated with the aim of combating both energy crises and environmental pollution problems. Anaerobic digestion was carried out in a two 10 L batch digesters for about 30 days under mesophilic condition. Biogas volume was measured by water displacement method at every 24h interval. Based on the volume of biogas produced and its methane composition, electricity value of the produced biogas was estimated. Daily average and cumulative gas volumes of 0.00103 m3/kg VS (1.03 liters) and 0.0309 m3/kg VS (30.90 liters) were obtained respectively with 63.4% methane composition. The results suggest that 1040 MWh and 1664.6 MWh of electricity can be generated from biogas at low-end conversion efficiency of 25% and at high-end high-end conversion efficiency respectively. The study concluded that waste to wealth technology, if appropriately explored is a viable solution to energy crises in Nigeria

Air Pollutant Emissions by Anthropogenic Combustion Processes in Lagos, Nigeria.

As part of research efforts to investigate the contribution of various anthropogenic activities to local atmospheric pollution load across Nigeria, the study investigated emission of air pollutants from the combustion processes in Lagos mega city. Solid wastes, consumption of fuel wood, and petroleum products were identified as major materials being combusted in Lagos and these materials were quantified based on the information in literature. Annual emissions from the combustion of the quantified materials were estimated using emission factor approach. The total estimated annual contribution of anthropogenic combustion processes to atmospheric loading of PM10, CO, SO2, NOx and VOC were 188.49, 5920.97, 11.24, 348.88 and 4.14 kt/annum, respectively. Emissions from the combustion of solid waste/biomass were identified as a major source of criteria air pollutants in the city because, about 67.5% and 82% of the estimated CO and PM10 emissions, respectively, were generated from the combustion of solid waste/biomass. Also, 81%, 57% and 32% of NOx, SO2 and CO emissions respectively were found to have emanated from combustion of kerosene. These elevated emission levels can be said to have potential impacts on ambient air quality of the study area. The study concluded that immediate mitigating action to reduce release of pollutants from combustion processes should be put in place