8 research outputs found
Effect of Nanoscale Zero-Valent Iron Treatment on Biological Reductive Dechlorination: A Review of Current Understanding and Research Needs
No full textabstract: Nanoscale zero-valent iron (nZVI) is a strong nonspecific reducing agent that is used for in situ degradation of chlorinated solvents and other oxidized pollutants. However, there are significant concerns regarding the risks posed by the deliberate release of engineered nanomaterials into the environment, which have triggered moratoria, for example, in the United Kingdom. This critical review focuses on the effect of nZVI injection on subsurface microbial communities, which are of interest due to their important role in contaminant attenuation processes. Corrosion of ZVI stimulates dehalorespiring bacteria, due to the production of H[subscript 2] that can serve as an electron donor for reduction of chlorinated contaminants. Conversely, laboratory studies show that nZVI can be inhibitory to pure bacterial cultures, although toxicity is reduced when nZVI is coated with polyelectrolytes or natural organic matter. The emerging toolkit of molecular biological analyses should enable a more sophisticated assessment of combined nZVI/biostimulation or bioaugmentation approaches. While further research on the consequences of its application for subsurface microbial communities is needed, nZVI continues to hold promise as an innovative technology for in situ remediation of pollutants It is particularly attractive. for the remediation of subsurface environments containing chlorinated ethenes because of its ability to potentially elicit and sustain both physical–chemical and biological removal despite its documented antimicrobial properties.This is an Author's Accepted Manuscript of an article published as Bruton, Thomas A., Pycke, Benny F. G., & Halden, Rolf U. (2015). Effect of Nanoscale Zero-Valent Iron Treatment on Biological Reductive Dechlorination: A Review of Current Understanding and Research Needs. CRITICAL REVIEWS IN ENVIRONMENTAL SCIENCE AND TECHNOLOGY, 45(11), 1148-1175. DOI: 10.1080/10643389.2014.924185. Copyright Taylor & Francis, available online at: http://www.tandfonline.com/doi/abs/10.1080/10643389.2014.92418
A time-course analysis of four full-scale anaerobic digesters in relation to the dynamics of change of their microbial communities
No full textThis study describes the microbial community richness, -dynamics, and -organization of four full-scale anaerobic digesters during a time-course study of 45 days. The microbial community was analyzed using a Bacteria- and Archaea-targeting 16S rRNA gene-based Terminal-Restriction Fragment Length Polymorphism approach. Clustering analysis separated meso- and thermophilic reactors for both archaeal and bacterial communities. Regardless of the operating temperature, each installation possessed a distinct community profile. For both microbial domains, about 8 dominant terminal-restriction fragments could be observed, with a minimum of 4 and a maximum of 14. The bacterial community organization (a coefficient which describes the specific degree of evenness) showed a factor 2 more variation in the mesophilic reactors, compared with the thermophilic ones. The archaeal community structure of the mesophilic UASB reactor was found to be more stable. The community composition was highly dynamic for Bacteria and Archaea, with a rate of change between 20-50% per 15 days. This study illustrated that microbial communities in full-scale anaerobic digesters are unique to the installation and that community properties are dynamic. Converging complex microbial processes such as anaerobic digestion which rely on a multitude of microbial teams apparently can be highly dynamic
Inventaire du chartrier et des archives de l'abbaye tournaisienne de Saint-Nicolas-des-Prés (1126-1795) reposant aux Archives et Bibliothèque de la cathédrale de Tournai
No full textAu moment de la suppression de l’abbaye Saint-Nicolas-des-Prés, le 1er septembre 1795, les archives de l’institution sont mises sous scellés et conservées sur place, dans ce qui devient, sous le régime français, une sous-préfecture du département de Jemappes (à savoir l’actuel séminaire diocésain de Tournai). Une partie importante des archives abbatiales gagne les archives communales de Tournai avant d’être transférées à Mons et, malheureusement, brûler en mai 1940.
En novembre 1807, soit quelques années après la signature du Concordat entre Napoléon et l’Eglise, le nouveau sous-préfet informe autorise la Fabrique de l’Eglise cathédrale à reprendre ses propres archives mises sous scellés et récupérer les « épaves » des archives provenant des abbayes tournaisiennes supprimées, Saint-Martin et Saint-Nicolas-des-Prés.
Le fonds de Saint-Nicolas-des-Prés représente l’équivalent de 21 boîtes d’archives : il compte 477 articles : 125 chartes originales, datant pour la plupart de l’époque médiévale, deux magnifiques cartulaires, quelques manuscrits, et surtout de pièces datant des 17e et 18e siècles. On peut ainsi connaître quelques épisodes de l’histoire du monastère de façon très détaillée. Nous pensons à l’installation de l’abbaye dans la paroisse Saint-Marguerite au 17e siècle, aux difficultés financières de Saint-Nicolas-des-Prés au milieu du siècle suivant, au déménagement dans l’ancien collège des Jésuites, au projet d’installer un hôpital militaire à l’abbaye et aux contributions exigées par le gouvernement français à la fin du 18e siècle.
L’inventaire proprement dit s’articule en sept sections, portant les lettres A à G : A. Chartes / B. Cartulaires / C. Généralités / D. Vie religieuse / E. Administration temporelle / F. Procès / G. Suppression de l’abbaye / H. Documentation sur l’abbaye datant d’après sa suppression
The relationship between needs and instruments of innovation policy in different regions: the Matrix INT - Instruments and Needs of Technology
No full textThe methodology, which is described in this study, aims to evaluate the gap between the characteristics of the demand and the supply of technology transfer (TT) services to small and medium size firms in a wide international framework, comprising both developed countries and less developed countries. The study focuses on a "demand led" and strategic approach. It underlies that the problems and opportunities of development of the small and medium size firms in the various individual countries are different and that determines a different structure of the demand of technology transfer services. Moreover, this study aims to identify the role and characteristics of the TT intermediaries in the wider framework of the strategies and instruments of innovation policies. In fact, the instruments of innovation policy are not only those, which operate directly on the individual firms, but also those, which can operate on the "selection environment", within which the firms are embedded. Key words: evaluation, innovation, technology transfer, regional policies
Transformation Products and Human Metabolites of Triclocarban and Triclosan in Sewage Sludge Across the United States
No full textRemoval
of triclocarban (TCC) and triclosan (TCS) from wastewater
is a function of adsorption, abiotic degradation, and microbial mineralization
or transformation, reactions that are not currently controlled or
optimized in the pollution control infrastructure of standard wastewater
treatment. Here, we report on the levels of eight transformation products,
human metabolites, and manufacturing byproducts of TCC and TCS in
raw and treated sewage sludge. Two sample sets were studied: samples
collected once from 14 wastewater treatment plants (WWTPs) representing
nine states, and multiple samples collected from one WWTP monitored
for 12 months. Time-course analysis of significant mass fluxes (α
= 0.01) indicate that transformation of TCC (dechlorination) and TCS
(methylation) occurred during sewage conveyance and treatment. Strong
linear correlations were found between TCC and the human metabolite
2′-hydroxy-TCC (<i>r</i> = 0.84), and between the
TCC-dechlorination products dichlorocarbanilide (DCC) and monochlorocarbanilide
(<i>r</i> = 0.99). Mass ratios of DCC-to-TCC and of methyl-triclosan
(MeTCS)-to-TCS, serving as indicators of transformation activity,
revealed that transformation was widespread under different treatment
regimes across the WWTPs sampled, though the degree of transformation
varied significantly among study sites (α = 0.01). The analysis
of sludge sampled before and after different unit operation steps
(i.e., anaerobic digestion, sludge heat treatment, and sludge drying)
yielded insights into the extent and location of TCC and TCS transformation.
Results showed anaerobic digestion to be important for MeTCS transformation
(37–74%), whereas its contribution to partial TCC dechlorination
was limited (0.4–2.1%). This longitudinal and nationwide survey
is the first to report the occurrence of transformation products,
human metabolites, and manufacturing byproducts of TCC and TCS in
sewage sludge
ОПРЕДЕЛЕНИЕ ФЕНОЛЬНЫХ СОЕДИНЕНИЙ В ДЕЗИНФЕКЦИОННЫХ СРЕДСТВАХ
No full textThe aspects of analytical determination of disinfectants derivatives of the phenol series аrе considered. The possibility of codetermination of five derivatives of this series in different disinfectants using the RP-HPLC method in the isocratic mode (UV detection) is shown. Alternatively, the possibilities of the determination with the use of spectrophotometry and GC methods are considered. This study and previous ones showed that the extraction of phenol derivatives by organic solvents from а wide range of disinfectants is feasible only in some cases, preferably with the use of hexane as an extractant. Further spectrophotometry of hexane extracts does not always enable to correctly compensate for the effect of background impurities and requires an additional separation of the components. The literature data and experimental results suggest that it is more efficient to analyze the whole series of disinfectants in isopropanol (sometimes in water) by chromatographic methods, preferably by HPLC. Sample preparation reduces to the solubilization of batches of ready-made disinfectants in isopropanol/water. It is optimal to carry out the chromatographic study using elution with acetonitrile-based systems (for example, СН3СN:Н2O, 60:40) providing the correct determination (λ = 280 nт) of phenol derivatives. The completeness of extraction (if the extraction method is used), as well as the metrology aspects of all the analytical determination is set directly in а laboratory during the realization of procedures of introduction/validation according to the internal documents of the system quality management for the relevant structural unit
