Reclamation of Hydrocarbon Contaminated Soils Using Soil Amendments and Native Plant Species

Abstract

Petroleum hydrocarbons are among the top contaminants of the natural environment with serious concern worldwide due to their effects on soil, water, and surroundings. A two-year field experiment was implemented to evaluate reclamation of hydrocarbon contaminated (diesel fuel, crude oil) soils in central Alberta Canada using amendments (20% city waste compost, ammonium sulphate inorganic fertilizer) and seeding with a native grass mix. Soils amended with compost or compost-fertilizer had the greatest vegetation cover and biomass and lowest hydrocarbon concentrations at the end of the study. Fertilizer treatments had less vegetation cover and higher hydrocarbon concentrations, which were similar to the no amendment treatment. Seeding with native grasses had no effect on hydrocarbon degradation or total canopy cover, although vegetation composition showed some effect. Seeding increased cover of perennial native grasses in all amendment treatments, with greatest cover in compost and compost-fertilizer amended soils. Within two years after reclamation concentrations of F2 (carbon length > C10–C16) and F4 (>C34–C60) hydrocarbons in crude oil contaminated soils were below Canadian guidelines. Overall, compost was an effective amendment for reclamation of diesel fuel and crude oil contaminated soils and seeding was beneficial for reducing cover of non-native forbs. Fertilizer addition to compost may not enhance revegetation and remediation of hydrocarbon contaminated soils.