When is a soil remediated? Comparison of biopiled and windrowed soils contaminated with bunker-fuel in a full-scale trial

Abstract

A six month field scale study was carried out to compare windrow turning and biopile techniques for the remediation of soil contaminated with bunker C fuel oil. End-point clean-up targets were defined by human risk assessment and ecotoxicological hazard assessment approaches. Replicate windrows and biopiles were amended with either nutrients and inocula, nutrients alone or no amendment. In addition to fractionated hydrocarbon analysis, culturable microbial characterisation and soil ecotoxicological assays were performed. This particular soil, heavy in texture and historically contaminated with bunker fuel was more effectively remediated by windrowing, but coarser textures may be more amendable to biopiling. This trial reveals the benefit of developing risk and hazard based approaches in defining end-point bioremediation of heavy hydrocarbons when engineered biopile or windrow are proposed as treatment option.

Exploiting the intrinsic hydrocarbon-degrading microbial capacities in oil tank bottom sludge and waste soil for sludge bioremediation

“…1 Changes in oil viscosity (a) and soil TPH levels in laboratory-based microcosms (b). Note For (a), cross symbol, triangle, square and diamond refer to microcosms with fungus, bacterial consortium, control at day 7 and control at day 0, respectively beneficial effect on hydrocarbon pollutant removal in soils has been reported in other studies (Stallwood et al 2005;Mancera-Lopez et al 2008;Coulon et al 2010). As oil tank bottom sludge contains a variety of microorganisms, it could be a more appropriate source of hydrocarbonoclastic microorganisms (as used in this study) for treating that oil tank bottom waste than microorganisms from other sources.…”

Ex-Situ Remediation Technologies for Environmental Pollutants: A Critical Perspective

“…While studying the effect of different strategies like bioaugmentation, biostimulation, and bioaugmentation plus biostimulation to enhance the petroleum hydrocarbon degradation in biopiles, Liu et al ( 2011b ) recorded >80 % TPH degradation after 140 days operation of a biopile subjected to the bioaugmentation approach (introduction of selected consortium and kitchen waste). Coulon et al ( 2010 ) conducted a fi eld study at a former dockyard in Scotland to compare the remedial effect of biopile and windrow turning technologies of a bunker C fuel-contaminated soil. It was witnessed that windrowing was most effective for treating the bunker fuel soils because the soil was more friable and biopiling is amenable to treating coarse soil textures.…”

Reviews of Environmental Contamination and Toxicology Volume 236

“…Wu and Crapper ( 2009 ) designed a hydraulic-based approach to stimulate a biopile in the context of its ambient temperature. Coulon et al ( 2010 ) conducted a fi eld study at a former dockyard in Scotland to compare the remedial effect of biopile and windrow turning technologies of a bunker C fuel-contaminated soil. A 28 m 3 pneumatically-aerated bioreactor set up in static biopile amended with manure oil compost (40 %) and garden waste compost (20 %) successfully removed 68.7 % petroleum hydrocarbons within 3-4 months treatment time (Kriipsalu and Nammari 2010 ).…”