Utilization of biosolids during the phytoremediation of hydrocarbon-contaminated soil.
Addition of anaerobically digested sewage sludge (biosolids) to soil may improve conditions for phytoremediation of petroleum hydrocarbons (PHCs) through improved soil chemical, biological, and physical properties. A 32-wk greenhouse study investigated three rates of biosolids addition (0, 13.34, and 26.68 g oven-dry biosolids kg(-1) oven-dry soil) and the presence or absence of smooth brome (Bromus inermis Leyss. cv. Carlton) plants on the removal of diesel (3.5 g kg(-1) oven-dry soil) in an industrial, sandy loam soil. Diesel PHCs were divided into two fractions based on equivalent normal straight-chain boiling point ranges (F2: nC10-nC16; F3: nC16-nC34). The addition of biosolids did not increase the extent of PHC degradation but did result in significantly greater first-order decay constants compared to unamended controls. Overall, the presence of plants did not increase the rate or extent of PHC degradation, relative to that observed in unamended, non-vegetated soils. Vegetation was, however, an important factor within the biosolids-amended soils as was observed by a greater extent of PHC degradation. Some of this decrease was attributed to plant-induced removal of biosolids components that were contributing to the F3 fraction. Overall, the low-amendment rate (13.34 g oven-dry biosolids kg(-1) oven-dry soil) was considered to be the most effective treatment because it produced the greatest overall PHC degradation rate (0.226 wk(-1) for total PHCs) and resulted in the greatest recovery of biosolids-derived N by smooth brome (26.6%).
Dickinson
S J
SJ
College of Science and Management, University of Northern British Columbia, 3333 University Way, Prince George, BC, Canada V2N 4Z9.
Rutherford
P M
PM
D000383:Agriculture; D001673:Biodegradation, Environmental; D018533:Biomass; D005308:Fertilizers; D006838:Hydrocarbons / Q000302:isolation & purification* / Q000378:metabolism; D007221:Industry; D009584:Nitrogen / Q000378:metabolism; D012722:Sewage / Q000032:analysis* / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000302:isolation & purification* / Q000378:metabolism
D005308:Fertilizers; D006838:Hydrocarbons; D012722:Sewage; D012989:Soil Pollutants; D009584:Nitrogen