Application of Carbon-Nitrogen Supplementation from Plant and Animal Sources in In-situ Soil Bioremediation of Diesel Oil: Experimental Analysis and Kinetic Modelling

In this study, the potential effects of sawdust, yam peel and mixture of cow dung, goat dung and poultry dung used alone or in combination as amendment/nutrient supplements to biostimulate autochthonous micro?ora for hydrocarbon biodegradation were investigated in microcosms containing soil spiked with diesel oil (10 % w/w). The rates of biodegradation of the diesel oil were studied for 42 days remediation period under laboratory conditions. The results showed that there was a positive relationship between the microbial growth, biodegradation rate and presence of the sawdust, yam peel and the mixture of cow dung, goat dung and poultry dung (alone or in combination) in microcosms simulated diesel oil contaminated soil.  The biodegradation data fitted well to first-order kinetic model. The model revealed that the combination of sawdust, yam peel, cow dung, goat dung and poultry dung elicited higher diesel oil biodegradation with biodegradation rate constant of 0.089 day-1 and half-life of 7.79 days. The system proposed here takes advantage of the organic wastes bulking properties as well as the autochthonous microorganism metabolic activity to efficiently degrade petroleum hydrocarbons. This system is inexpensive, efficient, and environmentally friendly and may thus offer a viable choice for petroleum hydrocarbons-contaminated soil remediation. Keywords: Biodegradation; Biostimulation; Diesel oil; Organic wastes; First-order kinetics; Half-life

Modelling of Pollutants Dispersion from Open Burning of Solid Waste Using AERMOD

This study evaluates the air quality impact of open burning of solid waste activities in Ilorin, Nigeria. An emission inventory was carried out to quantify the emitted CO, NOx and SOx from 2016- 2020 into the study area. Their ground level concentrations were computed with the Industrial Source Complex – American Meteorological Society (AMS) and United State Environmental Protection Agency (EPA) Regulatory Model (AERMOD) dispersion model and compared with standards to determine their impacts on ambient air quality. The average hourly, daily and annual concentrations were 25,267 µg/m3, 4,609 µg/m3, 447 µg/m3 for carbon monoxide (CO); 4,700 µg/m3, 730 µg/m3, 130 µg/m3 for oxides of nitrogen (NOx) and 954 µg/m3, 144 µg/m3, 24 µg/m3 for oxides of sulphur (SOx) respectively. The hourly air quality for CO were within the World Bank standard for all the receptor communities except at Abe-Emi with 2.17 folds, while the daily air quality was within the Federal Ministry of Environment (FMEnV) limit. However, the 1-h, 24-h and annual air quality for NOx exceeded the FMEnV and World Bank standard for all the receptor communities. Similarly, the hourly and daily air quality for SOx exceeded the FMEnV and World Bank standard for all the receptor communities

Ambient noise from off-grid diesel engines electric power generators in an urban environment

Abstract Purpose – The aim of this paper is to investigate the impacts of the noise from the diesel engine power generators used for production activities in an urban environment. Design/methodology/approach – This study has used the Enterprise Edition of NoiseMap 2000 Version 2.7.1 to investigate the impacts of the noise from the diesel engines electric power generators used in a factory in Ikorodu, an urban environment in Lagos, Nigeria. Five sections of the factory with diesel engines electric power generators were considered. The immediate and distant environments covering about 10 km of the factory host environment were considered as receptors to the noise for this study. Findings – It was found out that when all the generators operate simultaneously in the factory, the ambient noise was 30.0-152.5 dB(A) with the minimum contribution within the factory being 70.0-84.4 dB(A) and the maximum contribution of 57.2-70.8 dB(A) outside the factory fence line. Though the maximum noise is 152.5 dB(A), the maximum noise of 70.8 dB(A) beyond the fence line shows a compliance with 70 dB(A) industrial and commercial area limit but breaches the 45 dB(A) and 55 dB(A) residential area limit of the World Bank. Research limitations/implications – As much as it would be desirable ambient noise level could not be measured in all the receptors’ locations covered by the modeling. However, the capability of themodeling software adopted makes this to have no negative impact on the quality of the findings of this study. Practical implications – The study will assist the public to determine the noise level safe region around diesel engine electric power generators. Originality/value – The paper highlights the challenges in which ambient noise from the use of off-grid generators used for industrial purposes could pose to the neighboring receptor environments