Nitrogen fertilizers stimulate desorption and biodegradation of gasoline aromatics in the soil from high Arctic permafrost active layer: A laboratory study

Abstract Bioremediation of gasoline contaminated soil from high Arctic permafrost active layer near the Zackenberg research station in Northeast Greenland was studied in 28 days in the laboratory at 10 °C, a relevant local summer temperature. Fates of gasoline aromatics were followed in two groups: monoaromatics and naphthalene homologs. The treatments were control, natural attenuation, and biostimulation with fertilizers inorganic NPK, urea, and methylene urea, respectively. No natural attenuation was observed. Among the fertilizers, only urea significantly decreased the total concentration under the initial level (by 47%) in 28 days. NPK and urea but not methylene urea enhanced the desorption and extractability of soil gasoline aromatics and bioremediation from day 7–28; more bioremediation was enhanced by urea. In the same period, NPK and urea did not differ in the biostimulation of monoaromatics while the bioremediation of naphthalene homologs was enhanced remarkably more by urea. Soil pH effect of fertilizers was also studied and showed dependence on temperature. Conclusively, urea showed superiority to NPK and methylene urea in biostimulation of gasoline aromatics in this study.