Browsing by Author "Paton, Graeme I."

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    Mineralisation of target hydrocarbons in three contaminated soils from former refinery facilities
    (Elsevier Science B.V., Amsterdam., 2011-02-28T00:00:00Z) Towell, M. G.; Bellarby, J.; Paton, Graeme I.; Coulon, Frederic; Pollard, Simon J. T.; Semple, Kirk T.
    This study investigated the microbial degradation of 14C-labelled hexadecane, octacosane, phenanthrene and pyrene and considered how degradation might be optimised in three genuinely hydrocarbon contaminated soils from former petroleum refinery sites. Hydrocarbon mineralisation by the indigenous microbial community was monitored over 23 d. Hydrocarbon mineralisation enhancement by nutrient amendment (biostimulation), hydrocarbon degrader addition (bioaugmentation) and combined nutrient and degrader amendment, was also explored. The ability of indigenous soil microflora to mineralise 14C-target hydrocarbons was appreciable; ≥ 16% mineralised in all soils. Generally, addition of nutrients or degraders increased the rates and extents of mineralisation of 14C-hydrocarbons. However, the addition of nutrients and degraders in combination had a negative effect upon 14C-octacosane mineralisation and resulted in lower extents of mineralisation in the three soils. In general, the rates and extents of mineralisation will be dependent upon treatment type, nature of the contamination and adaptation of the ingenious microbial communit
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    Multimedia fate of petroleum hydrocarbons in the soil: Oil matrix of constructed biopiles
    (Elsevier Science B.V., Amsterdam., 2010-12-31T00:00:00Z) Coulon, Frederic; Whelan, Michael J.; Paton, Graeme I.; Semple, Kirk T.; Villa, Raffaella; Pollard, Simon J. T.
    A dynamic multimedia fugacity model was used to evaluate the partitioning and fate of petroleum hydrocarbon fractions and aromatic indicator compounds within the soil: oil matrix of three biopiles. Each biopile was characterised by four compartments: air, water, soil solids and non-aqueous phase liquid (NAPL). Equilibrium partitioning in biopile A and B suggested that most fractions resided in the NAPL, with the exception of the aromatic fraction with an equivalent carbon number from 5 to 7 (EC5-7). In Biopile C, which had the highest soil organic carbon content (13%), the soil solids were the most important compartment for both light aliphatic fractions (EC5-6 and EC6-8) and aromatic fractions, excluding the EC16-21 and EC21-35. Our starting hypothesis was that hydrocarbons do not degrade within the NAPL. This was supported by the agreement between predicted and measured hydrocarbon concentrations in Biopile B when the degradation rate constant in NAPL was set to zero. In all scenarios, biodegradation in soil was predicted as the dominant removal process for all fractions, except for the aliphatic EC5-6 which was predominantly lost via volatilization. The absence of an explicit NAPL phase in the model yielded a similar prediction of total petroleum hydrocarbon (TPH) behaviour; however the predicted concentrations in the air and water phases were significantly increased with consequent changes in potential mobility. Further comparisons between predictions and measured data, particularly concentrations in the soil mobile phases, are required to ascertain the true value of including an explicit NAPL in models of this kind.
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    Optimising the biopiling of weathered hydrocarbons within a risk management framework - PROMISE.
    (2005-04-01T00:00:00Z) Pollard, Simon J. T.; Hough, Rupert L.; Brassington, Kirsty J.; Sinke, Anja; Crossley, Jane; Paton, Graeme I.; Semple, Kirk T.; Risdon, Graeme C.; Jackman, Simon J.; Bone, B.; Jacobsen, Christian; Lethbridge, Gordon
    Thirty years of research into petroleum microbiology and bioremediation have bypassed an important observation – that many hydrocarbon contaminated sites posing potential risks to human health harbour weathered, ‘mid-distillate’ or heavy oils (Pollard, 2003). Ex-situ biopiling is an important technology for treating soils contaminated with weathered hydrocarbons. However, its performance continues to be represented by reference to reductions in the hydrocarbon ‘load’ in the soils being treated, rather than reductions in the risks posed by the hydrocarbon contamination (Owens and Bourgouin, 2003; Tien et al., 1999). The absence of ‘risk’ from the vocabulary of many operators and remediation projects reduces stakeholder (regulatory, investor, landowner, and public) confidence in remediation technologies, and subsequently limits the market potential of these technologies. Stakeholder confidence in the biopiling of weathered hydrocarbons may therefore be improved by demonstrating process optimisation within a validated risk management framework. To address these issues, a consortium led by Cranfield University’s Integrated Waste Management Centre has secured funding from the Government’s Bioremediation LINK programme. Project PROMISE (involving BP, SecondSite Regeneration Ltd., Dew Remediation Ltd., TES Bretby (Mowlem Group), technology translators PERA, and academics from Aberdeen, Cranfield and Lancaster Universities) aims to improve market confidence in biopiling by demonstrating how this treatment may be applied within a risk m
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    Optimising the biopiling of weathered hydrocarbons within a risk management framework.
    (2005-10-01T00:00:00Z) Hough, Rupert L.; Brassington, Kirsty J.; Sinke, Anja; Crossley, Jane; Paton, Graeme I.; Semple, Kirk T.; Risdon, Graeme C.; Jacobsen, Christian; Daly, Paddy; Jackman, Simon J.; Lethbridge, Gordon; Pollard, Simon J. T.
    Thirty years of research into petroleum microbiology and bioremediation have bypassed an important observation – that many hydrocarbon contaminated sites posing potential risks to human health harbour weathered, ‘mid-distillate’ or heavy oils rather than ‘fresh product’ (Pollard, 2003). Ex-situ biopiling is an important technology for treating soils contaminated with weathered hydrocarbons. However, its performance continues to be represented by reference to reductions in the hydrocarbon ‘load’ in the soils being treated, rather than reductions in the risks posed by the hydrocarbon contamination (Owens and Bourgouin, 2003; Tien et al., 1999). The absence of ‘risk’ from the vocabulary of many operators and remediation projects reduces stakeholder (regulatory, investor, landowner, and public) confidence in remediation technologies, and subsequently limits the market potential of these technologies. Stakeholder confidence in the biopiling of weathered hydrocarbons may be improved by demonstrating process optimisation within a validated risk man
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    Temporal changes in the extractability, bioaccessibility and biodegradation of target hydrocarbons in soils from former refinery facilities
    (Elsevier, 2021-04-22) Towell, Marcie G.; Vázquez-Cuevas, Gabriela M.; Bellarby, Jessica; Paton, Graeme I.; Pollard, Simon J. T.; Semple, Kirk T.
    This study investigated the extractability, bioaccessibility and biodegradation of 14C-phenanthrene and 14C-octacosane in two soils from former oil refinery facilities over 341 days. The impact of biostimulation and bioaugmentation treatments was also evaluated. At 0, 31, 62, 124 and 341 days, the loss and extractability (using dichloromethane, methanol:water and hydroxypropyl-β-cyclodextrin (HPCD)) of the 14C-hydrocarbons were measured. Further at each time point, the mineralisation of the 14C-hydrocarbons was measured respirometrically under the different conditions. In general, extractions with methanol: water and HPCD were similar for both hydrocarbons in the different treatments; however, these values were less that those measured with DCM. Overall, significantly higher (p ≤ 0.05) amounts of 14C-phenanthrene were lost, readily extracted and mineralised in the soils, with treatments having little impact upon the degradation of this hydrocarbon over 341 days. Conversely, bioaugmentation significantly increased the loss of 14C-octacosane residues from soils and sustained degradation after 31 days. Surprisingly, HPCD and methanol:water both under-predicted the extent to which the contaminants were degraded at each time point. Determining the likelihood of effective biodegradation by the stimulation of indigenous microorganisms or through bioaugmentation needs to be assessed by both chemical and biological measurements of bioaccessibility, rather than just by that which is totally extractable from soil. However, soils which have high loadings of organic matter and/or organic contaminants may prevent accurate assessment of contaminant bioaccessibility, as measured by HPCD.
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    Weathered Hydrocarbon Wastes: A Risk Management Primer
    (Taylor & Francis, 2007-05-01T00:00:00Z) Brassington, Kirsty J.; Hough, Rupert L.; Paton, Graeme I.; Semple, Kirk T.; Risdon, Graeme C.; Crossley, Jane; Hay, I.; Askari, K.; Pollard, Simon J. T.
    We provide a primer and critical review of the characterization, risk assessment, and bioremediation of weathered hydrocarbons. Historically the remediation of soil contaminated with petroleum hydrocarbons has been expressed in terms of reductions in total petroleum hydrocarbon (TPH) load rather than reductions in risk. There are several techniques by which petroleum hydrocarbons in soils can be characterized. Method development is often driven by the objectives of published risk assessment frameworks. Some frameworks stipulate analysis of a wide range of petroleum hydrocarbons; for example, the United Kingdom (UK) approach suggests compounds from EC5 to EC70 be examined. Methods for the extraction of petroleum hydrocarbons from soil samples have been reviewed extensively in the open literature. Although various extraction and analytical methods are available for petroleum hydrocarbons, their results suffer from inter-method variation, with gas chromatography methods being used widely. Currently, the implications for risk assessment are uncertain. Bioremediation works well for remediating soils contaminated with petroleum hydrocarbons. As a result, the optimization of environmental conditions is imperative. For petroleum hydrocarbons in soil, international regulatory guidance on the management of risks from contaminated sites is now emerging. There is also growing support for the move toward compound-specific risk-based approaches for the assessment of hydrocarbon-contaminated land.
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    When is a soil remediated? Comparison of biopiled and windrowed soils contaminated with bunker-fuel in a full-scale trial
    (Elsevier Science B.V., Amsterdam., 2010-10-31T00:00:00Z) Coulon, Frederic; Al, Awadi M.; Cowie, W.; Mardlin, D.; Pollard, Simon J. T.; Cunningham, C.; Risdon, Graeme C.; Arthur, P.; Semple, Kirk T.; Paton, Graeme I.
    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. (c) 2010 Elsevier Ltd. All rights reserved.