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

Abstract

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.