Browsing by Author "Paton, Graeme I."
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Item Open Access 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 communitItem Open Access 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, GordonThirty 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 mItem Open Access 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 manItem Open Access 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.