Bioremediation of diesel contaminated soil using biostimulation, bioaugmentation and bulking agents.

摘要

Petroleum hydrocarbons account for approximately 60% of contaminated sites in Canada. Atlantic Canada, especially in the Eastern region of the Province of Newfoundland and Labrador, which is known for quite a number of hydrocarbon-contaminated soils. Laboratory experiments in two phases were undertaken to compare the influence of nutrients, inocula and bulking agents additions on the bioremediation of diesel-fuel contaminated soil over a 90-day testing period. Phase I experiments determined the effect of one type of nutrient (either poultry manure or liquid cow manure), one type of inoculum (either indigenous or exogenous microbial inoculum) and one type of bulking agent (either sand or hay) on the degradation of diesel fuel in soil. Phase II experiments involved a series of laboratory-based experiments conducted to study the interactions among the nutrients, inocula and bulking agents additions.;After a 90-day experimental period, 96.6% degradation was achieved in contaminated soil containing clean Ottawa sand as a bulking agent in phase I experiments while 96.2% degradation was achieved in contaminated soil containing an inoculum of soil indigenous microbes and clean Ottawa sand in phase II experiments. The biodegradation results were analyzed to determine the most significant factors and interactions using Design-Expert® version 6 software for Design of Experiments. Additions of nutrients and bulking agents was found to be statistically significant, while the addition of inocula and the interactions among the nutrients, inocula and bulking agents were statistically significant.