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Val rie B caert Maude Beaulieu Jos e Gagnon Richard Villemur Louise Deschê nes R jean Samson 《Bioremediation Journal》2001,5(3):183-192
An indigenous microbial consortium capable of degrading pentachlorophenol (PCP) and petroleum hydrocarbons (C10-C50) was produced from a soil contaminated with wood-preserving oil. Two 10-L stainless steel soil slurry (10% w/v) bioreactors were operated in fed-batch mode. To verify the growth and efficiency of PCP degraders in the presence of other contaminants, one bioreactor was fed with a PCP-based wood-preserving mixture (WPM) and a second reactor was fed with technical-grade NaPCP. During the 90-day period of activation, PCP, C10-C50, Cl-, pH, and dissolved oxygen levels were monitored. The microbial community was monitored using specific most probably number (MPN) bacterial counts and mineralization tests. PCP degradation rates increased similarly in both reactors, from 19 to 132 mg/L-d in the NaPCP reactor, and from 41 to 112 mg/L-d in the WPM reactor. Contaminant loss calculations showed that 99.5% of PCP and 92.5% of C10-C50 added to the WPM reactor were biodegraded. It also revealed that 83% of polychlorinated dioxins and furans were removed. PCP-degrading bacteria increased from 7×102 to 1.6×106 bacteria/mL in both reactors, and petroleum hydrocarbon degraders increased from 1.7×102 to 3.4×108 bacteria/mL in the WPM reactor, indicating that the activity of PCP degraders was not inhibited by the presence of microorganisms growing on petroleum hydrocarbons. 相似文献
2.
Evaluating the variability of aquatic acidification and photochemical ozone formation characterization factors for Canadian emissions 总被引:1,自引:0,他引:1
Samuel Fréchette-Marleau Valérie Bécaert Manuele Margni Réjean Samson Louise Deschênes 《The International Journal of Life Cycle Assessment》2008,13(7):593-604
Background, aim, and scope The Canadian life cycle impact assessment method LUCAS proposes a characterization of the impact categories aquatic acidification
and photochemical ozone formation using a resolution scale based on 15 terrestrial ecozones. Each ecozone represents areas
of the country which can be identified easily by general living (biotic) and nonliving (abiotic) characteristics. The three
main purposes of this research are to improve the characterization models of both impact categories including regional exposure
and effect factors, to investigate what is the best resolution scale between Canadian provinces or ecozones, and to analyze
the extent of spatial variability.
Materials and methods A model framework accounting for variability in fate, exposure and effect factors has been elaborated. The same fate factor,
based on Advanced Statistical Trajectory Regional Air Pollution matrices, applies to both impact categories. For the aquatic
acidification impact category, the fate factor also accounts for the fraction of the deposition transferred to the aquatic
ecosystem. The exposure factor for this impact category is considered to be 1 and the effect factor is based on the critical
load exceedance, where the potential impacts are only considered in provinces or ecozones in which the critical load is exceeded.
For the photochemical ozone formation impact category, the exposure factor is considered to be proportional to the population
density in each province or ecozone, and the effect factor is represented by the chemical reactivity estimated with the maximum
incremental reactivity model. The calculation of the new characterization factors using both a province-based and ecozone
resolution scale was performed using a matrix which converts data from one resolution scale to another.
Results Results with the inclusion of the effect and the exposure factors show that the spatial variability between provinces remains
within a factor of 10 and 5 for aquatic acidification and photochemical ozone formation, respectively.
Discussion Analysis of the results show that regionalization by province is preferable to regionalization by ecozone. It is more accurate
in regard to atmospheric modeling and more representative of population distribution. However, averaging the fate factor and
the population density over a whole province results in a serious limitation.
Conclusions The spatial variability of characterization factors between provinces is in the same order of magnitude as the overall range
between chemicals for aquatic acidification while much smaller for photochemical ozone formation. Hence, at this stage of
knowledge, province-based regionalization seems to be more relevant for the aquatic acidification impact category than for
photochemical ozone formation.
Recommendations and perspectives Research must be pursued to integrate a better transport and deposition model with improved spatial capabilities and a successive
modeling step properly describing the cause–effect chain up to the damage level, such as the biotic environment and the human
population. 相似文献
3.
The microbiota of completely mixed soil slurry was acclimated with pentachlorophenol (PCP) or with a wood preservative mixture
(WPM) containing several pollutants such as PCP and petroleum hydrocarbons. The impact of these compounds on the bacterial
diversity was studied by using molecular tools. PCR amplifications of the 16S ribosomal RNA gene sequences (rDNA) were carried
out with total DNA extracted from soil slurry samples taken at different time points during the enrichment process of the
PCP and WPM reactors. The composition of these PCR products, reflecting the bacterial diversity, was monitored by the single-strand-conformation
polymorphism (SSCP) method. Our results showed that the complexity of the SSCP profiles in the PCP reactor decreased significantly
during the enrichment process, whereas they remained complex in the WPM reactor. PCR-amplified 16 rDNA libraries were generated
from each reactor. The SSCP method was used to rapidly screen several clones of these libraries to find specific single-strand
DNA migration profiles. In the PCP-activated soil, 96% of examined clones had the same SSCP profile, and sequences of representative
clones were related to the genusSphingomonas, suggesting that the enrichment with PCP resulted in a selection of little phylogenetic diversity. Four different SSCP profiles
were observed with the 68 examined clones from the WPM reactor. Representative clones of these profiles were related to Methylocystaceae
or Rhizobiaceae, to sulfur-oxidizing symbionts, to the genusAcinetobacter, and to the genusSphingomonas. We also cloned and sequenced PCR-amplified DNA related to thepcpB gene, coding for theSphingomonas PCP-4-monooxygenase and detected in both reactors after two weeks of enrichment. Of the 16 examined clones, deduced amino
acid sequences of 13 clones were highly related to theSphingomonas sp. strain UG30pcpB. The three remainingpcpB clones were not closely related to the three knownSphingomonas pcpB. 相似文献
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Alexandre Courchesne Valérie Bécaert Ralph K. Rosenbaum Louise Deschênes Réjean Samson 《Journal of Industrial Ecology》2010,14(2):309-321
As governments elaborate strategies to counter climate change, there is a need to compare the different options available on an environmental basis. This study proposes a life cycle assessment framework integrating the Lashof accounting methodology, which enables the assessment and comparison of different carbon mitigation projects (e.g., biofuel use, a sequestering plant, an afforestation project). The Lashof accounting methodology is chosen amid other methods of greenhouse gas (GHG) emission characterization for its relative simplicity and capability to characterize all types of carbon mitigation projects. Using the unit of megagram‐year (Mg‐year), which accounts for the mass of GHGs in the atmosphere multiplied by the time it stays there, the methodology calculates the cumulative radiative forcing caused by GHG emission within a predetermined time frame. Basically, the developed framework uses the Mg‐year as a functional unit and isolates impacts related to the climate mitigation function with system expansion. The proposed framework is demonstrated with a case study of tree ethanol pathways (maize, sugarcane, and willow). The study shows that carbon mitigation assessment through life cycle assessment is possible and that it could be a useful tool for decision makers, as it can compare different projects regardless of their original context. The case study reveals that system expansion, as well as each carbon mitigation project's efficiency at reducing carbon emissions, are critical factors that have a significant impact on the results. Also, the framework proves to be useful for treating land‐use change emissions, as they are considered through the functional unit. 相似文献
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A simple method to evaluate the concentration of pentachlorophenol degraders in contaminated soils 总被引:2,自引:0,他引:2
A new most probable number (MPN) method for the determination of pentachlorophenol (PCP) degraders in soil using the change in pH due to PCP degradation is compared with a well documented MPN method using radiolabeled PCP. The results of all MPN counts were similar within a 95% confidence limit. The results obtained in MPN per gram of dry soil using pH measurements were 1.8 (+3.1, -1.03) x10 (4) compared to 0.64 (+1.34, -0.42) x 10(4) when using production of [(14)C]CO(2). 相似文献
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