WorldWideScience

Sample records for bioremediation spatial similarities

  1. Bacterial Community Succession During in situ Uranium Bioremediation: Spatial Similarities Along Controlled Flow Paths

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Chiachi; Wu, Weimin; Gentry, Terry J.; Carley, Jack; Corbin, Gail A.; Carroll, Sue L.; Watson, David B.; Jardine, Phil M.; Zhou, Jizhong; Criddle, Craig S.; Fields, Matthew W.

    2009-05-22

    Bacterial community succession was investigated in a field-scale subsurface reactor formed by a series of wells that received weekly ethanol additions to re-circulating groundwater. Ethanol additions stimulated denitrification, metal reduction, sulfate reduction, and U(VI) reduction to sparingly soluble U(IV). Clone libraries of SSU rRNA gene sequences from groundwater samples enabled tracking of spatial and temporal changes over a 1.5 y period. Analyses showed that the communities changed in a manner consistent with geochemical variations that occurred along temporal and spatial scales. Canonical correspondence analysis revealed that the levels of nitrate, uranium, sulfide, sulfate, and ethanol strongly correlated with particular bacterial populations. As sulfate and U(VI) levels declined, sequences representative of sulfate-reducers and metal-reducers were detected at high levels. Ultimately, sequences associated with sulfate-reducing populations predominated, and sulfate levels declined as U(VI) remained at low levels. When engineering controls were compared to the population variation via canonical ordination, changes could be related to dissolved oxygen control and ethanol addition. The data also indicated that the indigenous populations responded differently to stimulation for bio-reduction; however, the two bio-stimulated communities became more similar after different transitions in an idiosyncratic manner. The strong associations between particular environmental variables and certain populations provide insight into the establishment of practical and successful remediation strategies in radionuclide-contaminated environments with respect to engineering controls and microbial ecology.

  2. Measurement of Similarity for Spatial Directions Between Areal Objects

    Institute of Scientific and Technical Information of China (English)

    DING Hong; GUO Qingsheng; DU Xiaohu

    2004-01-01

    Similarity for spatial directions plays an important role in GIS. In this paper, the conventional approaches are analyzed. Based on raster data areal objects, the authors propose two new methods for measuring similarity among spatial directions. One is to measure the similarity among spatial directions based on the features of raster data and the changes of distances between spatial objects, the other is to measure the similarity among spatial directions according to the variation of each raster cell centroid angle. The two methods overcome the complexity of measuring similarity among spatial directions with direction matrix model and solve the limitation of small changes in direction. The two methods are simple and have broader applicability.

  3. Content-based Image Retrieval by Spatial Similarity

    Directory of Open Access Journals (Sweden)

    Archana M. Kulkarn

    2002-07-01

    Full Text Available Similarity-based retrieval of images is an important task in image databases. Most of the user's queries are on retrieving those database images that are spatially similar to a query image. In defence strategies, one wants to know a number of armoured vehicles, such as battle tanks, portable missile launching vehicles, etc. moving towards it, so that one can decide counter strategy. Content-based spatial similarity retrieval of images can be used to locate spatial relationship of various objects in a specific area from the aerial photographs and to retrieve images similar to the query image from image database. A content-based image retrieval system that efficiently and effectively retrieves information from a defence image database along with the architecture for retrieving images by spatial similarity is presented. A robust algorithm SIMdef for retrieval by spatial similarity is proposed that utilises both directional and topological relations for computing similarity between images, retrieves similar images and recognises images even after they undergo modelling transformations (translation, scale and rotation. A case study for some of the common objects, used in defence applications using SIMdef algorithm, has been done.

  4. Effects of Spatial Frequency Similarity and Dissimilarity on Contour Integration.

    Directory of Open Access Journals (Sweden)

    Malte Persike

    Full Text Available We examined the effects of spatial frequency similarity and dissimilarity on human contour integration under various conditions of uncertainty. Participants performed a temporal 2AFC contour detection task. Spatial frequency jitter up to 3.0 octaves was applied either to background elements, or to contour and background elements, or to none of both. Results converge on four major findings. (1 Contours defined by spatial frequency similarity alone are only scarcely visible, suggesting the absence of specialized cortical routines for shape detection based on spatial frequency similarity. (2 When orientation collinearity and spatial frequency similarity are combined along a contour, performance amplifies far beyond probability summation when compared to the fully heterogenous condition but only to a margin compatible with probability summation when compared to the fully homogenous case. (3 Psychometric functions are steeper but not shifted for homogenous contours in heterogenous backgrounds indicating an advantageous signal-to-noise ratio. The additional similarity cue therefore not so much improves contour detection performance but primarily reduces observer uncertainty about whether a potential candidate is a contour or just a false positive. (4 Contour integration is a broadband mechanism which is only moderately impaired by spatial frequency dissimilarity.

  5. Similarity

    Science.gov (United States)

    Apostol, Tom M. (Editor)

    1990-01-01

    In this 'Project Mathematics! series, sponsored by the California Institute for Technology (CalTech), the mathematical concept of similarity is presented. he history of and real life applications are discussed using actual film footage and computer animation. Terms used and various concepts of size, shape, ratio, area, and volume are demonstrated. The similarity of polygons, solids, congruent triangles, internal ratios, perimeters, and line segments using the previous mentioned concepts are shown.

  6. BIOREMEDIATION TRAINING

    Science.gov (United States)

    Bioremediation encompasses a collection of technologies which use microbes to degrade or transform contaminants. Three technologies have an established track record of acceptable performance: aerobic bioventing for fuels; enhanced reductive dechlorination for chlorinated solvent...

  7. Cometabolic bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Hazen, Terry C.

    2009-02-15

    Cometabolic bioremediation is probably the most under appreciated bioremediation strategy currently available. Cometabolism strategies stimulate only indigenous microbes with the ability to degrade the contaminant and cosubstrate e.g. methane, propane, toluene and others. This highly targeted stimulation insures that only those microbes that can degrade the contaminant are targeted, thus reducing amendment costs, well and formation plugging, etc. Cometabolic bioremediation has been used on some of the most recalcitrant contaminants, e.g. PCE, TCE, MTBE, TNT, dioxane, atrazine, etc. Methanotrophs have been demonstrated to produce methane monooxygense, an oxidase that can degrade over 300 compounds. Cometabolic bioremediation also has the advantage of being able to degrade contaminants to trace concentrations, since the biodegrader is not dependent on the contaminant for carbon or energy. Increasingly we are finding that in order to protect human health and the environment that we must remediate to lower and lower concentrations, especially for compounds like endocrine disrupters, thus cometabolism may be the best and maybe the only possibility that we have to bioremediate some contaminants.

  8. A Quantitative Calculation Method of Composite Spatial Direction Similarity Concerning Scale Differences

    Directory of Open Access Journals (Sweden)

    CHEN Zhanlong

    2016-03-01

    Full Text Available This article introduces a new model for direction relations between multiple spatial objects at multiple scales and a corresponding similarity assessment method. The model is an improvement of direction relation matrix, which quantitatively models direction relations on object scale, and by the idea of decomposition and means of the optimum solution of the transportation problem to solve the minimum conversion cost between multiple direction matrices, namely distance between a pair of matrices, thus quantified the difference between a pair of directions, finally obtain the similarity values between arbitrary pairs of multiple spatial objects and compare the results. Experiments on calculating similarity between objects at different scales show that the presented method is efficient, accurate, and capable of obtaining results consistent with human cognition.

  9. Spatial-Temporal Congestion Identification Based on Time Series Similarity Considering Missing Data.

    Science.gov (United States)

    Qi, Hongsheng; Liu, Meiqi; Wang, Dianhai; Chen, Mengwei

    2016-01-01

    Traffic congestion varies spatially and temporally. The observation of the formation, propagation and dispersion of network traffic congestion can lead to insights about the network performance, the bottleneck dynamics etc. While many researchers use the traffic flow data to reconstruct the congestion profile, the data missing problem is bypassed. Current methods either omit the missing data or supplement the missing part by average etc. Great error may be introduced during these processes. Rather than simply discarding the missing data, this research regards the data missing event as a result of either the severe congestion which prevent the floating vehicle from entering the congested area, or a type of feature of the resulting traffic flow time series. Hence a new traffic flow operational index time series similarity measurement is expected to be established as a basis of identifying the dynamic network bottleneck. The method first measures the traffic flow operational similarity between pairs of neighboring links, and then the similarity results are used to cluster the spatial-temporal congestion. In order to get the similarity under missing data condition, the measurement is implemented in a two-stage manner: firstly the so called first order similarity is calculated given that the traffic flow variables are bounded both upside and downside; then the first order similarity is aggregated to generate the second order similarity as the output. We implement the method on part of the real-world road network; the results generated are not only consistent with empirical observation, but also provide useful insights.

  10. Biodegradation and bioremediation

    DEFF Research Database (Denmark)

    Albrechtsen, H.-J.

    1996-01-01

    Anmeldelse af Alexander,M.: Biodegradation and bioremediation. Academic Press, Sandiego, USA, 1994......Anmeldelse af Alexander,M.: Biodegradation and bioremediation. Academic Press, Sandiego, USA, 1994...

  11. Self-similar spatial structure of a streamer-free nanosecond discharge

    Science.gov (United States)

    Karelin, V. I.; Tren'kin, A. A.

    2008-03-01

    The microstructure of a current channel is experimentally found under the conditions when homogeneous air gaps are subjected to nanosecond voltage pulses in an electric field insufficient for streamer generation. As a possible mechanism of microstructure formation, instability of the ionization process at the avalanche stage leading to the formation of a self-similar spatial structure is considered. The fractal dimension of this structure is determined. In inhomogeneous gaps, the avalanche is shown to be unstable as well. The energy benefit of structuring is considered. It is demonstrated that the microstructure of streamer discharges in homogeneous gaps can also be treated in terms of the model suggested.

  12. Spatially pooled contrast responses predict neural and perceptual similarity of naturalistic image categories.

    Directory of Open Access Journals (Sweden)

    Iris I A Groen

    Full Text Available The visual world is complex and continuously changing. Yet, our brain transforms patterns of light falling on our retina into a coherent percept within a few hundred milliseconds. Possibly, low-level neural responses already carry substantial information to facilitate rapid characterization of the visual input. Here, we computationally estimated low-level contrast responses to computer-generated naturalistic images, and tested whether spatial pooling of these responses could predict image similarity at the neural and behavioral level. Using EEG, we show that statistics derived from pooled responses explain a large amount of variance between single-image evoked potentials (ERPs in individual subjects. Dissimilarity analysis on multi-electrode ERPs demonstrated that large differences between images in pooled response statistics are predictive of more dissimilar patterns of evoked activity, whereas images with little difference in statistics give rise to highly similar evoked activity patterns. In a separate behavioral experiment, images with large differences in statistics were judged as different categories, whereas images with little differences were confused. These findings suggest that statistics derived from low-level contrast responses can be extracted in early visual processing and can be relevant for rapid judgment of visual similarity. We compared our results with two other, well- known contrast statistics: Fourier power spectra and higher-order properties of contrast distributions (skewness and kurtosis. Interestingly, whereas these statistics allow for accurate image categorization, they do not predict ERP response patterns or behavioral categorization confusions. These converging computational, neural and behavioral results suggest that statistics of pooled contrast responses contain information that corresponds with perceived visual similarity in a rapid, low-level categorization task.

  13. Similarity between Spatial-temporal Expression Patterning of HOXA11 and Progesterone Receptor in Human Endometrium

    Institute of Scientific and Technical Information of China (English)

    Li-fen WANG; Hong-zhi LUO; Zheng-mei ZHU; Jie-dong WANG

    2003-01-01

    Objective To study HOXAll expression and its correlation with that of the progesterone receptor(PR) gene in human endometriumMethods In situ hybridization and semi-quantitative RT-PCR were used.Results HOXA l l mRNA was detected in both stromal and glandular cells of normal endometrium bv in situ hybridization. But the expression levels in the glandular cells had a dramatic decline or even disappearance at mid-secretory stage.Semi-quantitative RT-PCR analysis, however, demonstrated that the total expression levels of HOXAll mRNA were markedly increased in the mid-secretory endometrium, which suggested that there was an increased expression in stromal cells. Similar results were obtained for PR gene expression in human endometrium by in situ hybridization and semi-quantitative RT-PCR analysis.Conclusion HOXAll gene spatial and temporal expression patterns were similar to that of PR gene in endometrium across menstrual cycle, and HOXA l l was closely related to the endometrial proltferation and differentiation during menstrual cycle, especially the establishment of receptive status in implantation.

  14. Joint Effect of Habitat Identity and Spatial Distance on Spiders’ Community Similarity in a Fragmented Transition Zone

    Science.gov (United States)

    Ziv, Yaron

    2016-01-01

    Understanding the main processes that affect community similarity have been the focus of much ecological research. However, the relative effects of environmental and spatial aspects in structuring ecological communities is still unresolved and is probably scale-dependent. Here, we examine the effect of habitat identity and spatial distance on fine-grained community similarity within a biogeographic transition zone. We compared four hypotheses: i) habitat identity alone, ii) spatial proximity alone, iii) non-interactive effects of both habitat identity and spatial proximity, and iv) interactive effect of habitat identity and spatial proximity. We explored these hypotheses for spiders in three fragmented landscapes located along the sharp climatic gradient of Southern Judea Lowlands (SJL), Israel. We sampled 14,854 spiders (from 199 species or morphospecies) in 644 samples, taken in 35 patches and stratified to nine different habitats. We calculated the Bray-Curtis similarity between all samples-pairs. We divided the pairwise values to four functional distance categories (same patch, different patches from the same landscape, adjacent landscapes and distant landscapes) and two habitat categories (same or different habitats) and compared them using non-parametric MANOVA. A significant interaction between habitat identity and spatial distance was found, such that the difference in mean similarity between same-habitat pairs and different-habitat pairs decreases with spatial distance. Additionally, community similarity decayed with spatial distance. Furthermore, at all distances, same-habitat pairs had higher similarity than different-habitats pairs. Our results support the fourth hypothesis of interactive effect of habitat identity and spatial proximity. We suggest that the environmental complexity of habitats or increased habitat specificity of species near the edge of their distribution range may explain this pattern. Thus, in transitions zones care should be taken

  15. Similarities in the Spatial Pattern of the Surface Flux Response to Present-Day Greenhouse Gases and Aerosols

    Science.gov (United States)

    Persad, G.; Ming, Y.; Ramaswamy, V.

    2014-12-01

    Recent studies suggest that present-day greenhouse gases (GHGs) and aerosols can produce remarkably similar patterns of climate response in fully coupled general circulation model (GCM) simulations, despite having significantly different spatial patterns of top-of-atmosphere (TOA) forcing. However, there is little understanding of the mechanisms of ocean-atmosphere interaction that could lead to the response pattern formation. Surface flux perturbations are a crucial pathway by which TOA forcing is communicated to the ocean, and may be a vital link in explaining the spatial similarities in the fully coupled responses to disparate TOA forcing patterns—a phenomenon with implications for detection and attribution, as well as the climate sensitivity to different forcers. We analyze the surface energy budget response to present-day aerosols versus GHGs in single forcing, fixed SST, atmospheric GCM experiments to identify mechanisms for response pattern formation via surface flux perturbations. We find that, although the TOA forcing spatial patterns of GHGs and aerosols are largely uncorrelated, their surface radiative and heat flux patterns are significantly anti-correlated. Furthermore, this anti-correlation is largely explained by similar (but sign-reversed) spatial patterns of surface latent and sensible heat flux response to the two forcers, particularly over the winter-hemisphere extratropical oceans. These are, in turn, driven by spatially similar perturbations in surface winds from changes in mean tropical and midlatitude circulation. These results suggest that the mean atmospheric circulation, which has many anti-symmetric responses to GHG and aerosol forcings, is an efficient homogenizer of spatial patterns in the surface heat flux response to heterogeneous TOA forcings, creating an atmosphere-only pathway for similarities in the fully coupled response.

  16. The Effects of Attitude Similarity, Spatial Relationship, and Task Difficulty on Interpersonal Attraction.

    Science.gov (United States)

    Krivonos, Paul D.

    1980-01-01

    Presents a study of the effects of the occupation of an individual's personal space on that individual's judgment of the invader when the invader's attitudes are known to the invadee. Also studies the effect of the difficulty of the task on the relationship between spatial orientation and interpersonal attraction. (JMF)

  17. In situ groundwater bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Hazen, Terry C.

    2009-02-01

    In situ groundwater bioremediation of hydrocarbons has been used for more than 40 years. Most strategies involve biostimulation; however, recently bioaugmentation have been used for dehalorespiration. Aquifer and contaminant profiles are critical to determining the feasibility and strategy for in situ groundwater bioremediation. Hydraulic conductivity and redox conditions, including concentrations of terminal electron acceptors are critical to determine the feasibility and strategy for potential bioremediation applications. Conceptual models followed by characterization and subsequent numerical models are critical for efficient and cost effective bioremediation. Critical research needs in this area include better modeling and integration of remediation strategies with natural attenuation.

  18. Suitable Region for Flue-cured Tobacco (Nicotiana glauca L.) Planting Based on Spatial Scene Similarity%Suitable Region for Flue-cured Tobacco (Nicotiana glauca L.) Planting Based on Spatial Scene Similarity

    Institute of Scientific and Technical Information of China (English)

    Junxiang DONG; Danhuai GUO; Xiaodong SHAO

    2012-01-01

    [Objective] The aim was to establish a model based on spatial scene similarity, for which soil, slope, transport, water conservancy, light, social economic factors in suitable planting areas were all considered. A new suitable planting area of flue-cured tobacco was determined by comparison and analysis, with consideration of excellent area. [Method] Totaling thirty natural factors were chosen, which were clas- sified into nine categories, from Longpeng Town (LP) and Shaochong Town (SC) in Shiping County in Honghe Hani and Yi Autonomous Prefecture. [Result] According to weights, the factors from high to low were as follows: soil〉light〉elevation〉slope〉 water conservancy〉transport〉baking facility〉planting plans over the years〉others. The similarity of geographical conditions in the area was 0.894 3, which indicated that the planting conditions in the two regions are similar. If farmer population in unit area, farmland quantity for individual farmer, labors in every household, activity in planting flue-cured tobacco and work of local instructor were considered, the weights of different factors were as follows: farmer population in unit area〉farmland quantity for individual farmer〉farmers' activity in planting flue-cured tobacco〉educational back- ground〉labor force in every household〉instructor〉population of farmers' children at- tending school. The similarity of geographical conditions was 0.703 1, which indicated that it is none-natural factors that influence yield and quality of flue-cured tobacco. [Conclusion] According to analysis on suitable planting area of flue-cured tobacco based on assessment of spatial scene similarity, similarity of growing conditions in two spatial scenes can be analyzed and evaluated, which would promote further exploration on, influencing factors and effects on tobacco production.

  19. Spatial Similarity Assessment of Point Clusters%空间点群目标相似度计算

    Institute of Scientific and Technical Information of China (English)

    刘涛; 杜清运; 闫浩文

    2011-01-01

    顾及到视觉认知的Gestalt原则,提出了一种综合考虑到点群的空间关系、空间分布和几何特征,注重空间点群的整体描述的相似度计算模型。实验结果表明,相似度计算结果与直观认知比较一致。%With the consideration of Gestalt principles in visual cognition,this paper proposed a similarity assessment model which has a comprehensive consideration of point cluster's spatial relationships,spatial distribution and geometry attributes.The topology relationship of point cluster is defined using point cluster's topology neighbors,the direction relationship and distance relationship is defined using point cluster's standard deviation ellipse,and then the computation method of point cluster's topology,direction and distance similarity assessment is given out on this basis.Also the distribution range and the distribution density of point cluster and their similarity assessment method is put forward.Finally the formal five factors were combined to do a whole assessment of point clusters similarity.Experiment results show that the similarity assessment is consistent with intuitive cognition.

  20. Fungi in Bioremediation

    Science.gov (United States)

    Gadd, G. M.

    2001-12-01

    Bioremediation research has concentrated on organic pollutants, although the range of substances that can be transformed or detoxified by microorganisms includes both natural and synthetic organic materials and inorganic pollutants. The majority of applications developed to date involve bacteria, with a distinct lack of appreciation of the potential roles and involvement of fungi in bioremediation, despite clear evidence of their metabolic and morphological versatility. This book highlights the potential of filamentous fungi, including mycorrhizas, in bioremediation and discusses the physiology and chemistry of pollutant transformations.

  1. Four-Dimensional Computerized Tomography (4D-CT) Reconstruction Based on the Similarity Measure of Spatial Adjacent Images

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shu-xu; ZHOU Ling-hong; CHEN Guang-jie; LIN Sheng-qu; YE Yu-sheng; ZHANG Hai-nan

    2008-01-01

    Objective:To investigate the feasibility of a 4D-CT reconstruction method based on the similarity principle of spatial adjacent images and mutual information measure. Methods:A motor driven sinusoidal motion platform made in house was used to create one-dimensional periodical motion that was along the longitudinal axis of the CT couch. The amplitude of sinusoidal motion was set to an amplitude of ±1 cm. The period of the motion was adjustable and set to 3.5 s. Phantom objects of two eggs were placed in a Styrofoam block, which in turn were placed on the motion platform. These objects were used to simulate volumes of interest undergoing ideal periodic motion. CT data of static phantom were acquired using a multi-slice general electric (GE) LightSpeed 16-slice CT scanner in an axial mode. And the CT data of periodical motion phantom were acquired in an axial and cine-mode scan. A software program was developed by using VC++ and VTK software tools to resort the CT data and reconstruct the 4D-CT. Then all of the CT data with same phase were sorted by the program into the same series based on the similarity principle of spatial adjacent images and mutual information measure among them, and 3D reconstruction of different phase CT data were completed by using the software. Results:All of the CT data were sorted accurately into different series based on the similarity principle of spatial adjacent images and mutual information measures among them. Compared with the unsorted CT data, the motion artifacts in the 3D reconstruction of sorted CT data were reduced significantly, and all of the sorted CT series result in a 4D-CT that reflected the characteristic of the periodical motion phantom. Conclusion:Time-resolved 4D-CT reconstruction can be implemented with any general multi-slice CT scanners based on the similarity principle of spatial adjacent images and mutual information measure.The process of the 4D-CT data acquisition and reconstruction were not restricted to the

  2. Integrated Field, Laboratory, and Modeling Studies to Determine the Effects of Linked Microbial and Physical Spatial Heterogeneity on Engineered Vadose Zone Bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Fred Brokman; John Selker; Mark Rockhold

    2004-01-26

    While numerous techniques exist for remediation of contaminant plumes in groundwater or near the soil surface, remediation methods in the deep vadose zone are less established due to complex transport dynamics and sparse microbial populations. There is a lack of knowledge on how physical and hydrologic features of the vadose zone control microbial growth and colonization in response to nutrient delivery during bioremediation. Yet pollution in the vadose zone poses a serious threat to the groundwater resources lying deeper in the sediment. While the contaminants may be slowly degraded by native microbial communities, microbial degradation rates rarely keep pace with the spread of the pollutant. It is crucial to increase indigenous microbial degradation in the vadose zone to combat groundwater contamination.

  3. Integrated Field, Laboratory, and Modeling Studies to Determine the Effects of Linked Microbial and Physical Spatial Heterogeneity on Engineered Vadose Zone Bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Brockman, Fred J.; Selker, John S.; Rockhold, Mark L.

    2004-10-31

    Executive Summary - While numerous techniques exist for remediation of contaminant plumes in groundwater or near the soil surface, remediation methods in the deep vadose zone are less established due to complex transport dynamics and sparse microbial populations. There is a lack of knowledge on how physical and hydrologic features of the vadose zone control microbial growth and colonization in response to nutrient delivery during bioremediation. Yet pollution in the vadose zone poses a serious threat to the groundwater resources lying deeper in the sediment. While the contaminants may be slowly degraded by native microbial communities, microbial degradation rates rarely keep pace with the spread of the pollutant. It is crucial to increase indigenous microbial degradation in the vadose zone to combat groundwater contamination...

  4. Wildfire and Spatial Patterns in Forests in Northwestern Mexico: The United States Wishes It Had Similar Fire Problems

    Directory of Open Access Journals (Sweden)

    Scott L. Stephens

    2008-12-01

    Full Text Available Knowledge of the ecological effect of wildfire is important to resource managers, especially from forests in which past anthropogenic influences, e.g., fire suppression and timber harvesting, have been limited. Changes to forest structure and regeneration patterns were documented in a relatively unique old-growth Jeffrey pine-mixed conifer forest in northwestern Mexico after a July 2003 wildfire. This forested area has never been harvested and fire suppression did not begin until the 1970s. Fire effects were moderate especially considering that the wildfire occurred at the end of a severe, multi-year (1999-2003 drought. Shrub consumption was an important factor in tree mortality and the dominance of Jeffrey pine increased after fire. The Baja California wildfire enhanced or maintained a patchy forest structure; similar spatial heterogeneity should be included in US forest restoration plans. Most US forest restoration plans include thinning from below to separate tree crowns and attain a narrow range for residual basal area/ha. This essentially produces uniform forest conditions over broad areas that are in strong contrast to the resilient forests in northern Baja California. In addition to producing more spatial heterogeneity in restoration plans of forests that once experienced frequent, low-moderate intensity fire regimes, increased use of US wildfire management options such as wildland fire use as well as appropriate management responses to non-natural ignitions could also be implemented at broader spatial scales to increase the amount of burning in western US forests.

  5. Bioremediation of nanomaterials

    Science.gov (United States)

    Chen, Frank Fanqing; Keasling, Jay D; Tang, Yinjie J

    2013-05-14

    The present invention provides a method comprising the use of microorganisms for nanotoxicity study and bioremediation. In some embodiment, the microorganisms are bacterial organisms such as Gram negative bacteria, which are used as model organisms to study the nanotoxicity of the fullerene compounds: E. coli W3110, a human related enterobacterium and Shewanella oneidensis MR-1, an environmentally important bacterium with versatile metabolism.

  6. Face Recognition Is Affected by Similarity in Spatial Frequency Range to a Greater Degree Than Within-Category Object Recognition

    Science.gov (United States)

    Collin, Charles A.; Liu, Chang Hong; Troje, Nikolaus F.; McMullen, Patricia A.; Chaudhuri, Avi

    2004-01-01

    Previous studies have suggested that face identification is more sensitive to variations in spatial frequency content than object recognition, but none have compared how sensitive the 2 processes are to variations in spatial frequency overlap (SFO). The authors tested face and object matching accuracy under varying SFO conditions. Their results…

  7. Similar processes but different environmental filters for soil bacterial and fungal community composition turnover on a broad spatial scale.

    Directory of Open Access Journals (Sweden)

    Nicolas Chemidlin Prévost-Bouré

    Full Text Available Spatial scaling of microorganisms has been demonstrated over the last decade. However, the processes and environmental filters shaping soil microbial community structure on a broad spatial scale still need to be refined and ranked. Here, we compared bacterial and fungal community composition turnovers through a biogeographical approach on the same soil sampling design at a broad spatial scale (area range: 13300 to 31000 km2: i to examine their spatial structuring; ii to investigate the relative importance of environmental selection and spatial autocorrelation in determining their community composition turnover; and iii to identify and rank the relevant environmental filters and scales involved in their spatial variations. Molecular fingerprinting of soil bacterial and fungal communities was performed on 413 soils from four French regions of contrasting environmental heterogeneity (Landesspatial variables also explained 3% to 9% of total variance. These variables highlighted significant spatial autocorrelation of both communities unexplained by the environmental variables measured and could partly be explained by dispersal limitations. Although the identified filters and their hierarchy were dependent on the region and organism, selection was systematically based on a common group of environmental variables: pH, trophic resources, texture and land use. Spatial autocorrelation was also important at

  8. Bioremediation of Creosote - contaminated Soil

    OpenAIRE

    BYSS, Marius

    2008-01-01

    Bioremediation of creosote-contaminated soil was studied employing the methods of soil microbial biology and using new gas chromatography-mass spectrometry-mass spectrometry analytical approach. The changes of the soil microbial community under the polycyclic aromatic hydrocarbons (PAH) pollution impact were analyzed and described, as well as the changes during the bioremediation experiments. Laboratory-scale bioremediation experiments using the soil microbial community (consisted of bacteria...

  9. Stone formation in peach fruit exhibits spatial coordination of the lignin and flavonoid pathways and similarity to Arabidopsis dehiscence

    Directory of Open Access Journals (Sweden)

    Piagnani M Claudia

    2010-02-01

    Full Text Available Abstract Background Lignification of the fruit endocarp layer occurs in many angiosperms and plays a critical role in seed protection and dispersal. This process has been extensively studied with relationship to pod shatter or dehiscence in Arabidopsis. Dehiscence is controlled by a set of transcription factors that define the fruit tissue layers and whether or not they lignify. In contrast, relatively little is known about similar processes in other plants such as stone fruits which contain an extremely hard lignified endocarp or stone surrounding a single seed. Results Here we show that lignin deposition in peach initiates near the blossom end within the endocarp layer and proceeds in a distinct spatial-temporal pattern. Microarray studies using a developmental series from young fruits identified a sharp and transient induction of phenylpropanoid, lignin and flavonoid pathway genes concurrent with lignification and subsequent stone hardening. Quantitative polymerase chain reaction studies revealed that specific phenylpropanoid (phenylalanine ammonia-lyase and cinnamate 4-hydroxylase and lignin (caffeoyl-CoA O-methyltransferase, peroxidase and laccase pathway genes were induced in the endocarp layer over a 10 day time period, while two lignin genes (p-coumarate 3-hydroxylase and cinnamoyl CoA reductase were co-regulated with flavonoid pathway genes (chalcone synthase, dihydroflavanol 4-reductase, leucoanthocyanidin dioxygen-ase and flavanone-3-hydrosylase which were mesocarp and exocarp specific. Analysis of other fruit development expression studies revealed that flavonoid pathway induction is conserved in the related Rosaceae species apple while lignin pathway induction is not. The transcription factor expression of peach genes homologous to known endocarp determinant genes in Arabidopsis including SHATTERPROOF, SEEDSTCK and NAC SECONDARY WALL THICENING PROMOTING FACTOR 1 were found to be specifically expressed in the endocarp while the

  10. GRACE BIOREMEDIATION TECHNOLOGIES - DARAMEND™ BIOREMEDIATION TECHNOLOGY. INNOVATIVE TECHNOLOGY EVALUATION REPORT

    Science.gov (United States)

    Grace Dearborn's DARAMEND™ Bioremediation Technology was developed to treat soils/sediment contaminated with organic contaminants using solid-phase organic amendments. The amendments increase the soil’s ability to supply biologically available water/nutrients to micro...

  11. BIOREMEDIATION OF PETROLEUM HYDROCARBONS: A FLEXIBLE VARIABLE SPEED TECHNOLOGY

    Science.gov (United States)

    The bioremediation of petroleum hydrocarbons has evolved into a number of different processes. These processes include in-situ aquifer bioremediation, bioventing, biosparging, passive bioremediation with oxygen release compounds, and intrinsic bioremediation. Although often viewe...

  12. ORD RESEARCH PRIORITIES IN BIOREMEDIATION

    Science.gov (United States)

    ORD is conducting research on bioremediation impacting Superfund sites, RCRA facilities, underground storage tanks and oil spills. Work supporting Superfund is focused on understanding monitored natural recovery in sediments for contaminants including PCBs and PAHs. Under RCRA,...

  13. Mechanisms of mercury bioremediation.

    Science.gov (United States)

    Essa, A M M; Macaskie, L E; Brown, N L

    2002-08-01

    Mercury is one of the most toxic heavy metals, and has significant industrial and agricultural uses. These uses have led to severe localized mercury pollution. Mercury volatilization after its reduction to the metallic form by mercury-resistant bacteria has been reported as a mechanism for mercury bioremediation [Brunke, Deckwer, Frischmuth, Horn, Lunsdorf, Rhode, Rohricht, Timmis and Weppen (1993) FEMS Microbiol. Rev. 11, 145-152; von Canstein, Timmis, Deckwer and Wagner-Dobler (1999) Appl. Environ. Microbiol. 65, 5279-5284]. The reduction/volatilization system requires to be studied further, in order to eliminate the escape of the metallic mercury into the environment. Recently we have demonstrated three different mechanisms for mercury detoxification in one organism, Klebsiella pneumoniae M426, which may increase the capture efficiency of mercury.

  14. Arctic bioremediation -- A case study

    Energy Technology Data Exchange (ETDEWEB)

    Smallbeck, D.R.; Ramert, P.C. (Harding Lawson Associates, Novato, CA (United States)); Liddell, B.V.

    1994-05-01

    This paper discusses the use of bioremediation as an effective method to clean up diesel-range hydrocarbon spills in northern latitudes. The results of a laboratory study of microbial degradation of hydrocarbons under simulated arctic conditions showed that bioremediation can be effective in cold climates and led to the implementation of a large-scale field program. The results of 3 years of field testing have led to a significant reduction in diesel-range hydrocarbon concentrations in the contaminated area.

  15. Bioremediation approaches for organic pollutants: a critical perspective.

    Science.gov (United States)

    Megharaj, Mallavarapu; Ramakrishnan, Balasubramanian; Venkateswarlu, Kadiyala; Sethunathan, Nambrattil; Naidu, Ravi

    2011-11-01

    Due to human activities to a greater extent and natural processes to some extent, a large number of organic chemical substances such as petroleum hydrocarbons, halogenated and nitroaromatic compounds, phthalate esters, solvents and pesticides pollute the soil and aquatic environments. Remediation of these polluted sites following the conventional engineering approaches based on physicochemical methods is both technically and economically challenging. Bioremediation that involves the capabilities of microorganisms in the removal of pollutants is the most promising, relatively efficient and cost-effective technology. However, the current bioremediation approaches suffer from a number of limitations which include the poor capabilities of microbial communities in the field, lesser bioavailability of contaminants on spatial and temporal scales, and absence of bench-mark values for efficacy testing of bioremediation for their widespread application in the field. The restoration of all natural functions of some polluted soils remains impractical and, hence, the application of the principle of function-directed remediation may be sufficient to minimize the risks of persistence and spreading of pollutants. This review selectively examines and provides a critical view on the knowledge gaps and limitations in field application strategies, approaches such as composting, electrobioremediation and microbe-assisted phytoremediation, and the use of probes and assays for monitoring and testing the efficacy of bioremediation of polluted sites.

  16. Applied bioremediation of petroleum hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Hinchee, R.E.; Kittel, J.A. [eds.] [Battelle Memorial Inst., Columbus, OH (United States); Reisinger, H.J. [ed.] [Integrated Science and Technology, Inc., Marietta, GA (United States)

    1995-12-31

    This volume is part of a ten volume set of papers derived from the Third International In Situ and On-Site Bioreclamation Symposium which was held in San Diego, California, in April 1995. The purpose of the conference was to provide a multidisciplinary forum for exchange of state-of-the-art information on bioremediation. The papers in this volume focus on petroleum hydrocarbon bioremediation, with an emphasis on pilot-scale and field-scale applications. Individual papers have been processed separately for inclusion in the appropriate data bases.

  17. Systems biology approach to bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Romy; Wu, Cindy H.; Hazen, Terry C.

    2012-06-01

    Bioremediation has historically been approached as a ‘black box’ in terms of our fundamental understanding. Thus it succeeds and fails, seldom without a complete understanding of why. Systems biology is an integrated research approach to study complex biological systems, by investigating interactions and networks at the molecular, cellular, community, and ecosystem level. The knowledge of these interactions within individual components is fundamental to understanding the dynamics of the ecosystem under investigation. Finally, understanding and modeling functional microbial community structure and stress responses in environments at all levels have tremendous implications for our fundamental understanding of hydrobiogeochemical processes and the potential for making bioremediation breakthroughs and illuminating the ‘black box’.

  18. [Development of bioremediation in China--a review].

    Science.gov (United States)

    Liu, Zhipei; Liu, Shuangjiang

    2015-06-01

    The development of bioremediation for contaminated soil in China during past 30 years was briefly reviewed, mainly including the developing stages, bioremediation techniques/strategies and their applications, and isolation, screening and characterizations of microbial strains for bioremediation as well as their efficiencies in bioremediation of contaminated soils. Finally, future development of bioremediation techniques/strategies and their applications were also discussed.

  19. Laboratory method used for bioremediation

    Science.gov (United States)

    Carman, M. Leslie; Taylor, Robert T.

    2000-01-01

    An improved method for in situ microbial filter bioremediation having increasingly operational longevity of an in situ microbial filter emplaced into an aquifer. A method for generating a microbial filter of sufficient catalytic density and thickness, which has increased replenishment interval, improved bacteria attachment and detachment characteristics and the endogenous stability under in situ conditions. A system for in situ field water remediation.

  20. In situ vadose zone bioremediation.

    Science.gov (United States)

    Höhener, Patrick; Ponsin, Violaine

    2014-06-01

    Contamination of the vadose zone with various pollutants is a world-wide problem, and often technical or economic constraints impose remediation without excavation. In situ bioremediation in the vadose zone by bioventing has become a standard remediation technology for light spilled petroleum products. In this review, focus is given on new in situ bioremediation strategies in the vadose zone targeting a variety of other pollutants such as perchlorate, nitrate, uranium, chromium, halogenated solvents, explosives and pesticides. The techniques for biostimulation of either oxidative or reductive degradation pathways are presented, and biotransformations to immobile pollutants are discussed in cases of non-degradable pollutants. Furthermore, research on natural attenuation in the vadose zone is presented.

  1. Intrinsic bioremediation of landfills interim report

    Energy Technology Data Exchange (ETDEWEB)

    Brigmon, R.L. [Westinghouse Savannah River Company, Aiken, SC (United States); Fliermans, C.B.

    1997-07-14

    Intrinsic bioremediation is a risk management option that relies on natural biological and physical processes to contain the spread of contamination from a source. Evidence is presented in this report that intrinsic bioremediation is occurring at the Sanitary Landfill is fundamental to support incorportion into a Corrective Action Plan (CAP).

  2. Diverse Metabolic Capacities of Fungi for Bioremediation.

    Science.gov (United States)

    Deshmukh, Radhika; Khardenavis, Anshuman A; Purohit, Hemant J

    2016-09-01

    Bioremediation refers to cost-effective and environment-friendly method for converting the toxic, recalcitrant pollutants into environmentally benign products through the action of various biological treatments. Fungi play a major role in bioremediation owing to their robust morphology and diverse metabolic capacity. The review focuses on different fungal groups from a variety of habitats with their role in bioremediation of different toxic and recalcitrant compounds; persistent organic pollutants, textile dyes, effluents from textile, bleached kraft pulp, leather tanning industries, petroleum, polyaromatic hydrocarbons, pharmaceuticals and personal care products, and pesticides. Bioremediation of toxic organics by fungi is the most sustainable and green route for cleanup of contaminated sites and we discuss the multiple modes employed by fungi for detoxification of different toxic and recalcitrant compounds including prominent fungal enzymes viz., catalases, laccases, peroxidases and cyrochrome P450 monooxygeneses. We have also discussed the recent advances in enzyme engineering and genomics and research being carried out to trace the less understood bioremediation pathways.

  3. Case study: Bioremediation in the Aleutian Islands

    Energy Technology Data Exchange (ETDEWEB)

    Steward, K.J.; Laford, H.D. [URS Consultants, Inc., Seattle, WA (United States)

    1995-12-31

    This case study describes the design, construction, and operation of a bioremediation pile on Adak Island, which is located in the Aleutian Island chain. Approximately 1,900 m{sup 3} of petroleum-contaminated soil were placed in the bioremediation pile. The natural bioremediation process was enhanced by an oxygen and nutrient addition system to stimulate microbial activity. Despite the harsh weather on the island, after the first 6 months of operation, laboratory analyses of soil samples indicated a significant (80%) reduction in diesel concentrations.

  4. Bioremediation of petroleum hydrocarbon-contaminated ground water: The perspectives of history and hydrology

    Science.gov (United States)

    Chapelle, F.H.

    1999-01-01

    Bioremediation, the use of microbial degradation processes to detoxify environmental contamination, was first applied to petroleum hydrocarbon-contaminated ground water systems in the early 1970s. Since that time, these technologies have evolved in some ways that were clearly anticipated early investigators, and in other ways that were not foreseen. The expectation that adding oxidants and nutrients to contaminated aquifers would enhance biodegradation, for example, has been born out subsequent experience. Many of the technologies now in common use such as air sparging, hydrogen peroxide addition, nitrate addition, and bioslurping, are conceptually similar to the first bioremediation systems put into operation. More unexpected, however, were the considerable technical problems associated with delivering oxidants and nutrients to heterogeneous ground water systems. Experience has shown that the success of engineered bioremediation systems depends largely on how effectively directions and rates of ground water flow can be controlled, and thus how efficiently oxidants and nutrients can be delivered to contaminated aquifer sediments. The early expectation that injecting laboratory-selected or genetically engineered cultures of hydrocarbon-degrading bacteria into aquifers would be a useful bioremediation technology has not been born out subsequent experience. Rather, it appears that petroleum hydrocarbon-degrading bacteria are ubiquitous in ground water systems and that bacterial addition is usually unnecessary. Perhaps the technology that was least anticipated early investigators was the development of intrinsic bioremediation. Experience has shown that natural attenuation mechanisms - biodegradation, dilution, and sorption - limit the migration of contaminants to some degree in all ground water systems. Intrinsic bioremediation is the deliberate use of natural attenuation processes to treat contaminated ground water to specified concentration levels at predetermined

  5. Treatment of a mud pit by bioremediation.

    Science.gov (United States)

    Avdalović, Jelena; Đurić, Aleksandra; Miletić, Srdjan; Ilić, Mila; Milić, Jelena; Vrvić, Miroslav M

    2016-08-01

    The mud generated from oil and natural gas drilling, presents a considerable ecological problem. There are still insufficient remedies for the removal and minimization of these very stable emulsions. Existing technologies that are in use, more or less successfully, treat about 20% of generated waste drilling mud, while the rest is temporarily deposited in so-called mud pits. This study investigated in situ bioremediation of a mud pit. The bioremediation technology used in this case was based on the use of naturally occurring microorganisms, isolated from the contaminated site, which were capable of using the contaminating substances as nutrients. The bioremediation was stimulated through repeated inoculation with a zymogenous microbial consortium, along with mixing, watering and biostimulation. Application of these bioremediation techniques reduced the concentration of total petroleum hydrocarbons from 32.2 to 1.5 g kg(-1) (95% degradation) during six months of treatment.

  6. Biomarkers of marine pollution and bioremediation

    Digital Repository Service at National Institute of Oceanography (India)

    Sarkar, A.

    pollution and bioremediation Anupam Sarkar Accepted: 1 February 2006 / Published online: 4 May 2006 C211 Springer Science+Business Media, LLC 2006 This special issue of Ecotoxicology is dealt with selected papers presented at the ‘International Workshop...

  7. Emerging technologies in bioremediation: constraints and opportunities.

    Science.gov (United States)

    Rayu, Smriti; Karpouzas, Dimitrios G; Singh, Brajesh K

    2012-11-01

    Intensive industrialisation, inadequate disposal, large-scale manufacturing activities and leaks of organic compounds have resulted in long-term persistent sources of contamination of soil and groundwater. This is a major environmental, policy and health issue because of adverse effects of contaminants on humans and ecosystems. Current technologies for remediation of contaminated sites include chemical and physical remediation, incineration and bioremediation. With recent advancements, bioremediation offers an environmentally friendly, economically viable and socially acceptable option to remove contaminants from the environment. Three main approaches of bioremediation include use of microbes, plants and enzymatic remediation. All three approaches have been used with some success but are limited by various confounding factors. In this paper, we provide a brief overview on the approaches, their limitations and highlights emerging technologies that have potential to revolutionise the enzymatic and plant-based bioremediation approaches.

  8. Biosurfactant-enhanced soil bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Kosaric, N.; Lu, G.; Velikonja, J. [Univ. of Western Ontario, London, Ontario (Canada)

    1995-12-01

    Bioremediation of soil contaminated with organic chemicals is a viable alternative method for clean-up and remedy of hazardous waste sites. The final objective in this approach is to convert the parent toxicant into a readily biodegradable product which is harmless to human health and/or the environment. Biodegradation of hydrocarbons in soil can also efficiently be enhanced by addition or in-situ production of biosufactants. It was generally observed that the degradation time was shortened and particularly the adaptation time for the microbes. More data from our laboratories showed that chlorinated aromatic compounds, such as 2,4-dichlorophenol, a herbicide Metolachlor, as well as naphthalene are degraded faster and more completely when selected biosurfactants are added to the soil. More recent data demonstrated an enhanced biodegradation of heavy hydrocarbons in petrochemical sludges, and in contaminated oil when biosurfactants were present or were added prior to the biodegradation process.

  9. Bioremediation Potential of Terrestrial Fuel Spills †

    OpenAIRE

    Song, Hong-Gyu; Wang, Xiaoping; Bartha, Richard

    1990-01-01

    A bioremediation treatment that consisted of liming, fertilization, and tilling was evaluated on the laboratory scale for its effectiveness in cleaning up a sand, a loam, and a clay loam contaminated at 50 to 135 mg g of soil−1 by gasoline, jet fuel, heating oil, diesel oil, or bunker C. Experimental variables included incubation temperatures of 17, 27, and 37°C; no treatment; bioremediation treatment; and poisoned evaporation controls. Hydrocarbon residues were determined by quantitative gas...

  10. Bioremediation of wastewater using microalgae

    Science.gov (United States)

    Chalivendra, Saikumar

    Population expansion and industrial development has deteriorated the quality of freshwater reservoirs around the world and has caused freshwater shortages in certain areas. Discharge of industrial effluents containing toxic heavy metals such as Cd and Cr into the environment have serious impact on human, animal and aquatic life. In order to solve these problems, the present study was focused on evaluating and demonstrating potential of microalgae for bioremediation of wastewater laden with nitrogen (N) in the form of nitrates, phosphorous (P) in the form of phosphates, chromium (Cr (VI)) and cadmium (Cd (II)). After screening several microalgae, Chlorella vulgaris and algae taken from Pleasant Hill Lake were chosen as candidate species for this study. The viability of the process was demonstrated in laboratory bioreactors and various experimental parameters such as contact time, initial metal concentration, algae concentration, pH and temperature that would affect remediation rates were studied. Based on the experimental results, correlations were developed to enable customizing and designing a commercial Algae based Wastewater Treatment System (AWTS). A commercial AWTS system that can be easily customized and is suitable for integration into existing wastewater treatment facilities was developed, and capital cost estimates for system including installation and annual operating costs were determined. The work concludes that algal bioremediation is a viable alternate technology for treating wastewater in an economical and sustainable way when compared to conventional treatment processes. The annual wastewater treatment cost to remove N,P is ~26x lower and to remove Cr, Cd is 7x lower than conventional treatment processes. The cost benefit analysis performed shows that if this technology is implemented at industrial complexes, Air Force freight and other Department of Defense installations with wastewater treatment plants, it could lead to millions of dollars in

  11. Web Similarity

    NARCIS (Netherlands)

    Cohen, A.R.; Vitányi, P.M.B.

    2015-01-01

    Normalized web distance (NWD) is a similarity or normalized semantic distance based on the World Wide Web or any other large electronic database, for instance Wikipedia, and a search engine that returns reliable aggregate page counts. For sets of search terms the NWD gives a similarity on a scale fr

  12. Bioremediation of oil-contaminated sites

    Energy Technology Data Exchange (ETDEWEB)

    Balba, T. [Conestoga-Rovers and Associates, Calgary, AB (Canada)

    2003-07-01

    One of the most prevalent contaminants in subsurface soil and groundwater are petroleum hydrocarbons. This paper presented bioremediation of petroleum hydrocarbons as one of the most promising treatment technologies. Petroleum hydrocarbons are categorized into four simple fractions: saturates, aromatics, resins, and asphaltenes. Bioremediation refers to the treatment process whereby contaminants are metabolized into less toxic or nontoxic compounds by naturally occurring organisms. The various strategies include: use of constitutive enzymes, enzyme induction, co-metabolism, transfer of plasmids coding for certain metabolic pathways, and production of biosurfactants to enhance bioavailability of hydrophobic compounds. Three case studies were presented: (1) bioremediation of heavy oils in soil at a locomotive maintenance yard in California, involving a multi-step laboratory treatability study followed by a field demonstration achieving up to 94 per cent removal of TPH in less than 16 weeks, (2) bioremediation of light oils in soil at an oil refinery in Germany where a dual process was applied (excavation and in-situ treatment), achieving an 84 per cent reduction within 24 weeks, and (3) bioremediation of oil-contaminated desert soil in Kuwait which involved landfarming, composting piles, and bioventing soil piles, achieving an 80 per cent reduction within 12 months. 7 refs., 1 tab., 3 figs.

  13. A Multiscale Approach to Optimal In Situ Bioremediation Design

    Science.gov (United States)

    Minsker, B. S.; Liu, Y.

    2001-12-01

    The use of optimization methods for in situ bioremediation design is quite challenging because the dynamics of bioremediation require that fine spatial and temporal scales be used in simulation, which substantially increases computational effort for optimization. In this paper, we present a multiscale approach that can be used to solve substantially larger-scale problems than previously possible. The multiscale method starts from a coarse mesh and proceeds to a finer mesh when it converges. While it is on a finer mesh, it switches back to a coarser mesh to calculate derivatives. The derivatives are then interpolated back to the finer mesh to approximate the derivatives on the finer mesh. To demonstrate the method, a four-level case study with 6,500 state variables is solved in less than 9 days, compared with nearly one year that would have been required using the original single-scale model. These findings illustrate that the multiscale method will allow solution of substantially larger-scale problems than previously possible, particularly since the method also enables easy parallelization of the model in the future.

  14. Espacialidade em Bakhtin e Pêcheux: semelhanças e dessemelhanças Spatiality in Bakhtin and Pêcheux: similarities and differences

    Directory of Open Access Journals (Sweden)

    Renata Silva

    2009-01-01

    Full Text Available O presente trabalho visa a uma análise comparativa das noções de "esfera", de Bakhtin (1992, 1999, e de "espaço discursivo", de Pêcheux (1997, com o intuito de elucidar o tratamento conferido à espacialidade pelos mencionados autores. Mostra que, embora haja consideráveis pontos de contato, "esfera" e "espaço discursivo" divergem quando entrecruzados com outros conceitos, desenvolvidos no âmbito da Teoria Dialógica e da Análise do Discurso de linha francesa (AD.The present work aims at a comparative analysis of the "sphere" notions, Bakhtin (1992, 1999, and of the "discursive space", Pêcheux (1997, with the intention of elucidating the treatment these authors give to spatiality. It shows that even though there might be considerable points of contact, "sphere" and "discursive space" diverge when intercrossed with other concepts developed in the ambit of the Dialogical Theory and of the French line of Speech Analysis (SA.

  15. Soil mesocosm studies on atrazine bioremediation.

    Science.gov (United States)

    Sagarkar, Sneha; Nousiainen, Aura; Shaligram, Shraddha; Björklöf, Katarina; Lindström, Kristina; Jørgensen, Kirsten S; Kapley, Atya

    2014-06-15

    Accumulation of pesticides in the environment causes serious issues of contamination and toxicity. Bioremediation is an ecologically sound method to manage soil pollution, but the bottleneck here, is the successful scale-up of lab-scale experiments to field applications. This study demonstrates pilot-scale bioremediation in tropical soil using atrazine as model pollutant. Mimicking field conditions, three different bioremediation strategies for atrazine degradation were explored. 100 kg soil mesocosms were set-up, with or without atrazine application history. Natural attenuation and enhanced bioremediation were tested, where augmentation with an atrazine degrading consortium demonstrated best pollutant removal. 90% atrazine degradation was observed in six days in soil previously exposed to atrazine, while soil without history of atrazine use, needed 15 days to remove the same amount of amended atrazine. The bacterial consortium comprised of 3 novel bacterial strains with different genetic atrazine degrading potential. The progress of bioremediation was monitored by measuring the levels of atrazine and its intermediate, cyanuric acid. Genes from the atrazine degradation pathway, namely, atzA, atzB, atzD, trzN and trzD were quantified in all mesocosms for 60 days. The highest abundance of all target genes was observed on the 6th day of treatment. trzD was observed in the bioaugmented mesocosms only. The bacterial community profile in all mesocosms was monitored by LH-PCR over a period of two months. Results indicate that the communities changed rapidly after inoculation, but there was no drastic change in microbial community profile after 1 month. Results indicated that efficient bioremediation of atrazine using a microbial consortium could be successfully up-scaled to pilot scale.

  16. Technical Basis for Assessing Uranium Bioremediation Performance

    Energy Technology Data Exchange (ETDEWEB)

    PE Long; SB Yabusaki; PD Meyer; CJ Murray; AL N’Guessan

    2008-04-01

    In situ bioremediation of uranium holds significant promise for effective stabilization of U(VI) from groundwater at reduced cost compared to conventional pump and treat. This promise is unlikely to be realized unless researchers and practitioners successfully predict and demonstrate the long-term effectiveness of uranium bioremediation protocols. Field research to date has focused on both proof of principle and a mechanistic level of understanding. Current practice typically involves an engineering approach using proprietary amendments that focuses mainly on monitoring U(VI) concentration for a limited time period. Given the complexity of uranium biogeochemistry and uranium secondary minerals, and the lack of documented case studies, a systematic monitoring approach using multiple performance indicators is needed. This document provides an overview of uranium bioremediation, summarizes design considerations, and identifies and prioritizes field performance indicators for the application of uranium bioremediation. The performance indicators provided as part of this document are based on current biogeochemical understanding of uranium and will enable practitioners to monitor the performance of their system and make a strong case to clients, regulators, and the public that the future performance of the system can be assured and changes in performance addressed as needed. The performance indicators established by this document and the information gained by using these indicators do add to the cost of uranium bioremediation. However, they are vital to the long-term success of the application of uranium bioremediation and provide a significant assurance that regulatory goals will be met. The document also emphasizes the need for systematic development of key information from bench scale tests and pilot scales tests prior to full-scale implementation.

  17. Bioremediation of Petroleum Hydrocarbon Contaminated Sites

    Energy Technology Data Exchange (ETDEWEB)

    Fallgren, Paul

    2009-03-30

    Bioremediation has been widely applied in the restoration of petroleum hydrocarbon-contaminated. Parameters that may affect the rate and efficiency of biodegradation include temperature, moisture, salinity, nutrient availability, microbial species, and type and concentration of contaminants. Other factors can also affect the success of the bioremediation treatment of contaminants, such as climatic conditions, soil type, soil permeability, contaminant distribution and concentration, and drainage. Western Research Institute in conjunction with TechLink Environmental, Inc. and the U.S. Department of Energy conducted laboratory studies to evaluate major parameters that contribute to the bioremediation of petroleum-contaminated drill cuttings using land farming and to develop a biotreatment cell to expedite biodegradation of hydrocarbons. Physical characteristics such as soil texture, hydraulic conductivity, and water retention were determined for the petroleum hydrocarbon contaminated soil. Soil texture was determined to be loamy sand to sand, and high hydraulic conductivity and low water retention was observed. Temperature appeared to have the greatest influence on biodegradation rates where high temperatures (>50 C) favored biodegradation. High nitrogen content in the form of ammonium enhanced biodegradation as well did the presence of water near field water holding capacity. Urea was not a good source of nitrogen and has detrimental effects for bioremediation for this site soil. Artificial sea water had little effect on biodegradation rates, but biodegradation rates decreased after increasing the concentrations of salts. Biotreatment cell (biocell) tests demonstrated hydrocarbon biodegradation can be enhanced substantially when utilizing a leachate recirculation design where a 72% reduction of hydrocarbon concentration was observed with a 72-h period at a treatment temperature of 50 C. Overall, this study demonstrates the investigation of the effects of

  18. Strategies for chromium bioremediation of tannery effluent.

    Science.gov (United States)

    Garg, Satyendra Kumar; Tripathi, Manikant; Srinath, Thiruneelakantan

    2012-01-01

    Bioremediation offers the possibility of using living organisms (bacteria, fungi, algae,or plants), but primarily microorganisms, to degrade or remove environmental contaminants, and transform them into nontoxic or less-toxic forms. The major advantages of bioremediation over conventional physicochemical and biological treatment methods include low cost, good efficiency, minimization of chemicals, reduced quantity of secondary sludge, regeneration of cell biomass, and the possibility of recover-ing pollutant metals. Leather industries, which extensively employ chromium compounds in the tanning process, discharge spent-chromium-laden effluent into nearby water bodies. Worldwide, chromium is known to be one of the most common inorganic contaminants of groundwater at pollutant hazardous sites. Hexavalent chromium poses a health risk to all forms of life. Bioremediation of chromium extant in tannery waste involves different strategies that include biosorption, bioaccumulation,bioreduction, and immobilization of biomaterial(s). Biosorption is a nondirected physiochemical interaction that occurs between metal species and the cellular components of biological species. It is metabolism-dependent when living biomass is employed, and metabolism-independent in dead cell biomass. Dead cell biomass is much more effective than living cell biomass at biosorping heavy metals, including chromium. Bioaccumulation is a metabolically active process in living organisms that works through adsorption, intracellular accumulation, and bioprecipitation mechanisms. In bioreduction processes, microorganisms alter the oxidation/reduction state of toxic metals through direct or indirect biological and chemical process(es).Bioreduction of Cr6+ to Cr3+ not only decreases the chromium toxicity to living organisms, but also helps precipitate chromium at a neutral pH for further physical removal,thus offering promise as a bioremediation strategy. However, biosorption, bioaccumulation, and

  19. Similarity Scaling

    Science.gov (United States)

    Schnack, Dalton D.

    In Lecture 10, we introduced a non-dimensional parameter called the Lundquist number, denoted by S. This is just one of many non-dimensional parameters that can appear in the formulations of both hydrodynamics and MHD. These generally express the ratio of the time scale associated with some dissipative process to the time scale associated with either wave propagation or transport by flow. These are important because they define regions in parameter space that separate flows with different physical characteristics. All flows that have the same non-dimensional parameters behave in the same way. This property is called similarity scaling.

  20. Optimization-based image reconstruction in x-ray computed tomography by sparsity exploitation of local continuity and nonlocal spatial self-similarity

    Science.gov (United States)

    Han-Ming, Zhang; Lin-Yuan, Wang; Lei, Li; Bin, Yan; Ai-Long, Cai; Guo-En, Hu

    2016-07-01

    The additional sparse prior of images has been the subject of much research in problems of sparse-view computed tomography (CT) reconstruction. A method employing the image gradient sparsity is often used to reduce the sampling rate and is shown to remove the unwanted artifacts while preserve sharp edges, but may cause blocky or patchy artifacts. To eliminate this drawback, we propose a novel sparsity exploitation-based model for CT image reconstruction. In the presented model, the sparse representation and sparsity exploitation of both gradient and nonlocal gradient are investigated. The new model is shown to offer the potential for better results by introducing a similarity prior information of the image structure. Then, an effective alternating direction minimization algorithm is developed to optimize the objective function with a robust convergence result. Qualitative and quantitative evaluations have been carried out both on the simulation and real data in terms of accuracy and resolution properties. The results indicate that the proposed method can be applied for achieving better image-quality potential with the theoretically expected detailed feature preservation. Project supported by the National Natural Science Foundation of China (Grant No. 61372172).

  1. MetaRouter: bioinformatics for bioremediation

    Science.gov (United States)

    Pazos, Florencio; Guijas, David; Valencia, Alfonso; De Lorenzo, Victor

    2005-01-01

    Bioremediation, the exploitation of biological catalysts (mostly microorganisms) for removing pollutants from the environment, requires the integration of huge amounts of data from different sources. We have developed MetaRouter, a system for maintaining heterogeneous information related to bioremediation in a framework that allows its query, administration and mining (application of methods for extracting new knowledge). MetaRouter is an application intended for laboratories working in biodegradation and bioremediation, which need to maintain and consult public and private data, linked internally and with external databases, and to extract new information from it. Among the data-mining features is a program included for locating biodegradative pathways for chemical compounds according to a given set of constraints and requirements. The integration of biodegradation information with the corresponding protein and genome data provides a suitable framework for studying the global properties of the bioremediation network. The system can be accessed and administrated through a web interface. The full-featured system (except administration facilities) is freely available at http://pdg.cnb.uam.es/MetaRouter. Additional material: http://www.pdg.cnb.uam.es/biodeg_net/MetaRouter. PMID:15608267

  2. In situ microbial filter used for bioremediation

    Science.gov (United States)

    Carman, M. Leslie; Taylor, Robert T.

    2000-01-01

    An improved method for in situ microbial filter bioremediation having increasingly operational longevity of an in situ microbial filter emplaced into an aquifer. A method for generating a microbial filter of sufficient catalytic density and thickness, which has increased replenishment interval, improved bacteria attachment and detachment characteristics and the endogenous stability under in situ conditions. A system for in situ field water remediation.

  3. Assessing TCE source bioremediation by geostatistical analysis of a flux fence.

    Science.gov (United States)

    Cai, Zuansi; Wilson, Ryan D; Lerner, David N

    2012-01-01

    Mass discharge across transect planes is increasingly used as a metric for performance assessment of in situ groundwater remediation systems. Mass discharge estimates using concentrations measured in multilevel transects are often made by assuming a uniform flow field, and uncertainty contributions from spatial concentration and flow field variability are often overlooked. We extend our recently developed geostatistical approach to estimate mass discharge using transect data of concentration and hydraulic conductivity, so accounting for the spatial variability of both datasets. The magnitude and uncertainty of mass discharge were quantified by conditional simulation. An important benefit of the approach is that uncertainty is quantified as an integral part of the mass discharge estimate. We use this approach for performance assessment of a bioremediation experiment of a trichloroethene (TCE) source zone. Analyses of dissolved parent and daughter compounds demonstrated that the engineered bioremediation has elevated the degradation rate of TCE, resulting in a two-thirds reduction in the TCE mass discharge from the source zone. The biologically enhanced dissolution of TCE was not significant (~5%), and was less than expected. However, the discharges of the daughter products cis-1,2, dichloroethene (cDCE) and vinyl chloride (VC) increased, probably because of the rapid transformation of TCE from the source zone to the measurement transect. This suggests that enhancing the biodegradation of cDCE and VC will be crucial to successful engineered bioremediation of TCE source zones.

  4. Integrative analysis of Geobacter spp. and sulfate-reducing bacteria during uranium bioremediation

    Science.gov (United States)

    Barlett, M.; Zhuang, K.; Mahadevan, R.; Lovley, D.

    2012-03-01

    Enhancing microbial U(VI) reduction with the addition of organic electron donors is a promising strategy for immobilizing uranium in contaminated groundwaters, but has yet to be optimized because of a poor understanding of the factors controlling the growth of various microbial communities during bioremediation. In previous field trials in which acetate was added to the subsurface, there were two distinct phases: an initial phase in which acetate-oxidizing, U(VI)-reducing Geobacter predominated and U(VI) was effectively reduced and a second phase in which acetate-oxidizing sulfate reducing bacteria (SRB) predominated and U(VI) reduction was poor. The interaction of Geobacter and SRB was investigated both in sediment incubations that mimicked in situ bioremediation and with in silico metabolic modeling. In sediment incubations, Geobacter grew quickly but then declined in numbers as the microbially reducible Fe(III) was depleted whereas the SRB grow more slowly and reached dominance after 30-40 days. Modeling predicted a similar outcome. Additional modeling in which the relative initial percentages of the Geobacter and SRB were varied indicated that there was little to no competitive interaction between Geobacter and SRB when acetate was abundant. Further simulations suggested that the addition of Fe(III) would revive the Geobacter, but have little to no effect on the SRB. This result was confirmed experimentally. The results demonstrate that it is possible to predict the impact of amendments on important components of the subsurface microbial community during groundwater bioremediation. The finding that Fe(III) availability, rather than competition with SRB, is the key factor limiting the activity of Geobacter during in situ uranium bioremediation will aid in the design of improved uranium bioremediation strategies.

  5. Integrative analysis of the interactions between Geobacter spp. and sulfate-reducing bacteria during uranium bioremediation

    Science.gov (United States)

    Barlett, M.; Zhuang, K.; Mahadevan, R.; Lovley, D. R.

    2011-11-01

    Enhancing microbial U(VI) reduction with the addition of organic electron donors is a promising strategy for immobilizing uranium in contaminated groundwaters, but has yet to be optimized because of a poor understanding of the factors controlling the growth of various microbial communities during bioremediation. In previous field trials in which acetate was added to the subsurface, there were two distinct phases: an initial phase in which acetate-oxidizing, U(VI)-reducing Geobacter predominated and U(VI) was effectively reduced and a second phase in which acetate-oxidizing sulfate reducing bacteria (SRB) predominated and U(VI) reduction was poor. The interaction of Geobacter and SRB was investigated both in sediment incubations that mimicked in situ bioremediation and with in silico metabolic modeling. In sediment incubations, Geobacter grew quickly but then declined in numbers as the microbially reducible Fe(III) was depleted whereas the SRB grow more slowly and reached dominance after 30-40 days. Modeling predicted a similar outcome. Additional modeling in which the relative initial percentages of the Geobacter and SRB were varied indicated that there was little to no competitive interaction between Geobacter and SRB when acetate was abundant. Further simulations suggested that the addition of Fe(III) would revive the Geobacter, but have little to no effect on the SRB. This result was confirmed experimentally. The results demonstrate that it is possible to predict the impact of amendments on important components of the subsurface microbial community during groundwater bioremediation. The finding that Fe(III) availability, rather than competition with SRB, is the key factor limiting the activity of Geobacter during in situ uranium bioremediation will aid in the design of improved uranium bioremediation strategies.

  6. Integrative analysis of Geobacter spp. and sulfate-reducing bacteria during uranium bioremediation

    Directory of Open Access Journals (Sweden)

    D. Lovley

    2012-03-01

    Full Text Available Enhancing microbial U(VI reduction with the addition of organic electron donors is a promising strategy for immobilizing uranium in contaminated groundwaters, but has yet to be optimized because of a poor understanding of the factors controlling the growth of various microbial communities during bioremediation. In previous field trials in which acetate was added to the subsurface, there were two distinct phases: an initial phase in which acetate-oxidizing, U(VI-reducing Geobacter predominated and U(VI was effectively reduced and a second phase in which acetate-oxidizing sulfate reducing bacteria (SRB predominated and U(VI reduction was poor. The interaction of Geobacter and SRB was investigated both in sediment incubations that mimicked in situ bioremediation and with in silico metabolic modeling. In sediment incubations, Geobacter grew quickly but then declined in numbers as the microbially reducible Fe(III was depleted whereas the SRB grow more slowly and reached dominance after 30–40 days. Modeling predicted a similar outcome. Additional modeling in which the relative initial percentages of the Geobacter and SRB were varied indicated that there was little to no competitive interaction between Geobacter and SRB when acetate was abundant. Further simulations suggested that the addition of Fe(III would revive the Geobacter, but have little to no effect on the SRB. This result was confirmed experimentally. The results demonstrate that it is possible to predict the impact of amendments on important components of the subsurface microbial community during groundwater bioremediation. The finding that Fe(III availability, rather than competition with SRB, is the key factor limiting the activity of Geobacter during in situ uranium bioremediation will aid in the design of improved uranium bioremediation strategies.

  7. Integrative analysis of the interactions between Geobacter spp. and sulfate-reducing bacteria during uranium bioremediation

    Directory of Open Access Journals (Sweden)

    D. R. Lovley

    2011-11-01

    Full Text Available Enhancing microbial U(VI reduction with the addition of organic electron donors is a promising strategy for immobilizing uranium in contaminated groundwaters, but has yet to be optimized because of a poor understanding of the factors controlling the growth of various microbial communities during bioremediation. In previous field trials in which acetate was added to the subsurface, there were two distinct phases: an initial phase in which acetate-oxidizing, U(VI-reducing Geobacter predominated and U(VI was effectively reduced and a second phase in which acetate-oxidizing sulfate reducing bacteria (SRB predominated and U(VI reduction was poor. The interaction of Geobacter and SRB was investigated both in sediment incubations that mimicked in situ bioremediation and with in silico metabolic modeling. In sediment incubations, Geobacter grew quickly but then declined in numbers as the microbially reducible Fe(III was depleted whereas the SRB grow more slowly and reached dominance after 30–40 days. Modeling predicted a similar outcome. Additional modeling in which the relative initial percentages of the Geobacter and SRB were varied indicated that there was little to no competitive interaction between Geobacter and SRB when acetate was abundant. Further simulations suggested that the addition of Fe(III would revive the Geobacter, but have little to no effect on the SRB. This result was confirmed experimentally. The results demonstrate that it is possible to predict the impact of amendments on important components of the subsurface microbial community during groundwater bioremediation. The finding that Fe(III availability, rather than competition with SRB, is the key factor limiting the activity of Geobacter during in situ uranium bioremediation will aid in the design of improved uranium bioremediation strategies.

  8. Similarity Measuring of Spatial Topological Relations Based on Topological Predication%基于拓扑谓词的空间拓扑关系相似性度量模型与应用

    Institute of Scientific and Technical Information of China (English)

    安晓亚; 杨云; 刘平芝

    2013-01-01

    Similarity measuring of spatial topological relations is the important part of similarity measuring of spatial data, and also is the basic and key technology of spatial data retrieval and spatial scene query. Its meaning is to measure the similarity of topological relationships between multiple data entities in different sources, differ-ent sources scales of the same region. Common topological relations have been abstracted into nine topological predications. Current researches mainly focus on the topological relations similarity measuring between two sim-ple entities, but mostly do not involve topological relations similarity measuring for the entire data sets, as well as the complex line targets. In this paper we present a method of measuring simple topological relations based on 9- intersection matrix, that is, the distance between two 9- intersection matrixes as the simple topological rela-tions distance to measure the differences between two simple topological relations, so that we can get a simple to-pological relations similarity. Then considering the quantity similarity and dimension similarity between entity sets, we can get the simple topological relations similarity measuring model between entity sets. In this paper we establish a similarity measuring model of complex topological predication by using the strategy of decompos-ing-combination based on the simple topological relations similarity measuring model. Firstly, the complex topol-ogy relationship is broken down into a number of local topological relationships. Then through a combination of local topological relations similarity, we get the complex topology relationship similarity measuring model. At last, the method is used to measure similarity of different scales and different sources data. Experimental results show that the selection of cartographic generalization impact the topological relations similarity between entity sets mostly, and other factors with smaller impacts to the experimental

  9. Selenite bioremediation potential of indigenous microorganisms from industrial activated sludge.

    Science.gov (United States)

    Garbisu, C; Alkorta, I; Carlson, D E; Leighton, T; Buchanan, B B

    1997-12-01

    Ten bacterial strains were isolated from the activated sludge waste treatment system (BIOX) at the Exxon refinery in Benicia, California. Half of these isolates could be grown in minimal medium. When tested for selenite detoxification capability, these five isolates (members of the genera Bacillus, Pseudomonas, Enterobacter and Aeromonas), were capable of detoxifying selenite with kinetics similar to those of a well characterized Bacillus subtilis strain (168 Trp+) studied previously. The selenite detoxification phenotype of the Exxon isolates was stable to repeated transfer on culture media which did not contain selenium. Microorganisms isolated from the Exxon BIOX reactor were capable of detoxifying selenite. Treatability studies using the whole BIOX microbial community were also carried out to evaluate substrates for their ability to support growth and selenite bioremediation. Under the appropriate conditions, indigenous microbial communities are capable of remediating selenite in situ.

  10. Improving Bioremediation of PAH Contaminated Soils by Thermal Pretreatment

    OpenAIRE

    Bonten, L.T.C.

    2001-01-01

    Numerous sites and large volumes of sediments in the Netherlands are contaminated with polycyclic aromatic hydrocarbons (PAH), which are of great concern because of their toxic and carcinogenic effects. Since PAH tend to sorb very strongly to the soil matrix, bioremediation is a slow process with often high residual concentrations after remediation. In this study it was tried to develop methods to improve bioremediation, this means to decrease residual concentrations after bioremediation. In ...

  11. Bioremediation of a tropical clay soil contaminated with diesel oil.

    Science.gov (United States)

    Chagas-Spinelli, Alessandra C O; Kato, Mario T; de Lima, Edmilson S; Gavazza, Savia

    2012-12-30

    The removal of polyaromatic hydrocarbons (PAH) in tropical clay soil contaminated with diesel oil was evaluated. Three bioremediation treatments were used: landfarming (LF), biostimulation (BS) and biostimulation with bioaugmentation (BSBA). The treatment removal efficiency for the total PAHs differed from the efficiencies for the removal of individual PAH compounds. In the case of total PAHs, the removal values obtained at the end of the 129-day experimental period were 87%, 89% and 87% for LF, BS and BSBA, respectively. Thus, the efficiency was not improved by the addition of nutrients and microorganisms. Typically, two distinct phases were observed. A higher removal rate occurred in the first 17 days (P-I) and a lower rate occurred in the last 112 days (P-II). In phase P-I, the zero-order kinetic parameter (μg PAH g(-1) soil d(-1)) values were similar (about 4.6) for all the three treatments. In P-II, values were also similar but much lower (about 0.14). P-I was characterized by a sharp pH decrease to less than 5.0 for the BS and BSBA treatments, while the pH remained near 6.5 for LF. Concerning the 16 individual priority PAH compounds, the results varied depending on the bioremediation treatment used and on the PAH species of interest. In general, compounds with fewer aromatic rings were better removed by BS or BSBA, while those with 4 or more rings were most effectively removed by LF. The biphasic removal behavior was observed only for some compounds. In the case of naphthalene, pyrene, chrysene, benzo[k]fluoranthene and benzo[a]pyrene, removal occurred mostly in the P-I phase. Therefore, the best degradation process for total or individual PAHs should be selected considering the target compounds and the local conditions, such as native microbiota and soil type.

  12. Bioremediation Education Science and Technology (BEST) Program Annual Report 1999

    Energy Technology Data Exchange (ETDEWEB)

    Hazen, Terry C.

    2000-07-01

    The Bioremediation, Education, Science and Technology (BEST) partnership provides a sustainable and contemporary approach to developing new bioremedial technologies for US Department of Defense (DoD) priority contaminants while increasing the representation of underrepresented minorities and women in an exciting new biotechnical field. This comprehensive and innovative bioremediation education program provides under-represented groups with a cross-disciplinary bioremediation cirruculum and financial support, coupled with relevant training experiences at advanced research laboratories and field sites. These programs are designed to provide a stream of highly trained minority and women professionals to meet national environmental needs.

  13. Natural and accelerated bioremediation research program plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    This draft plan describes a ten-year program to develop the scientific understanding needed to harness and develop natural and enhanced biogeochemical processes to bioremediate contaminated soils, sediments and groundwater at DOE facilities. The Office of Health and Environmental Research (OHER) developed this program plan, with advice and assistance from DOE`s Office of Environmental Management (EM). The program builds on OHER`s tradition of sponsoring fundamental research in the life and environmental sciences and was motivated by OHER`s and Office of Energy Research`s (OER`s) commitment to supporting DOE`s environmental management mission and the belief that bioremediation is an important part of the solution to DOE`s environmental problems.

  14. Biosurfactant-enhanced bioremediation of hydrophobic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Cameotra, S.S.; Makkar, R.S. [Inst. of Microbial Technology, Chandigarh (India)

    2010-01-15

    Biosurfactants are surface-active compounds synthesized by a wide variety of microorganisms. They are molecules that have both hydrophobic and - philic domains and are capable of lowering the surface tension and the interfacial tension of the growth medium. Biosurfactants possess different chemical structures-lipopeptides, glycolipids, neutral lipids, and fatty acids. They are nontoxic biomolecules that are biodegradable. Biosurfactants also exhibit strong emulsification of hydrophobic compounds and form stable emulsions. Polycyclic aromatic hydrocarbons (PAHs), crude on sludge, and pesticides call be toxic, mutagenic, and carcinogenic compounds that pollute the environment. They are released into the environment as a result of oil spillage and by-products of coal treatment processes. The low water solubility of these compounds limits their availability to microorganisms, which is a potential problem for bioremediation of contaminated sites. Microbially produced surfactants enhance the bioavailability of these hydrophobic compounds for bioremediation. Therefore, biosurfactant-enhanced solubility of pollutants has potential hioremediation applications.

  15. Fungal Bioremediation of Creosote-contaminated Soil

    OpenAIRE

    BYSS, Marius

    2008-01-01

    The influence of two ligninolytic fungi (Pleurotus ostreatus and Irpex lacteus) on bioremediation of creosote-contaminated soil was studied. The thesis describes the polycyclic aromatic hydrocarbon concentration decrease during the laboratory-scale experiments and reveals the changes in the present soil microbial community under the influence of either fungus. The thesis compares different impact on PAH concentrations and soil microbial community depending on the fungus applied.

  16. The enzymatic basis for pesticide bioremediation

    OpenAIRE

    Scott, Colin; Pandey, Gunjan; Hartley, Carol J.; Jackson, Colin J.; Cheesman, Matthew J.; Taylor, Matthew C.; Pandey, Rinku; Khurana, Jeevan L.; Teese, Mark; Coppin, Chris W; Weir, Kahli M.; Jain, Rakesh K.; Lal, Rup; Russell, Robyn J.; Oakeshott, John G.

    2008-01-01

    Enzymes are central to the biology of many pesticides, influencing their modes of action, environmental fates and mechanisms of target species resistance. Since the introduction of synthetic xenobiotic pesticides, enzymes responsible for pesticide turnover have evolved rapidly, in both the target organisms and incidentally exposed biota. Such enzymes are a source of significant biotechnological potential and form the basis of several bioremediation strategies intended to reduce the environmen...

  17. [Response of soil microbial community to the bioremediation of soil contaminated with PAHs].

    Science.gov (United States)

    Zhang, Jing; Lin, Xian-gui; Liu, Wei-wei; Yin, Rui

    2012-08-01

    The diversity of bacterial community in soil contaminated with polycyclic aromatic hydrocarbons (PAHs) was investigated during the plant-microbe remediation enhanced by biosurfactant rhamnolips (RH), using the polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) method. The results showed that Shannon-Weaver diversity index was only 3.17 before bioremediation, and increased to 3.24-3.45 after bioremediation, in particular, highest value was found in the treatment of alfalfa (AL) inoculated with arbuscular mycorrhizal fungi (AM) and PAHs-degrading bacteria (DB) among all the treatments. The clustering analysis showed that the similarities of soil bacterial community of AL, AL + RH, AL + AM and AL + AM + RH were above 90%. At the same time, the similarity of AL + DB was much closer to those of the four treatments mentioned above. Additionally, when the bacterial communities of AL + DB + RH, AL + DB + AM and AL + DB + AM + RH were grouped together, the similarities of these three treatments were also higher than 80%. By sequence alignment, it was found that the predominant and characteristic bands in DGGE patterns were closely related with PAHs-degrading bacteria, such as Bacillus, Pseudomonas, Acidobacteria, Sphingmonas, Rhodopseudomonas, Firmicutes, and Methylocytaceae. Application of rhamnolipids in plant-microbe bioremediation not only improved the bioavailability of PAHs, but also had a simultaneous influence on the diversity of soil bacterial community, resulting in the efficient promotion of PAHs removal from soils.

  18. A scrutiny of heterogeneity at the TCE Source Area BioREmediation (SABRE) test site

    Science.gov (United States)

    Rivett, M.; Wealthall, G. P.; Mcmillan, L. A.; Zeeb, P.

    2015-12-01

    A scrutiny of heterogeneity at the UK's Source Area BioREmediation (SABRE) test site is presented to better understand how spatial heterogeneity in subsurface properties and process occurrence may constrain performance of enhanced in-situ bioremediation (EISB). The industrial site contained a 25 to 45 year old trichloroethene (TCE) dense non-aqueous phase liquid (DNAPL) that was exceptionally well monitored via a network of multilevel samplers and high resolution core sampling. Moreover, monitoring was conducted within a 3-sided sheet-pile cell that allowed a controlled streamtube of flow to be drawn through the source zone by an extraction well. We primarily focus on the longitudinal transect of monitoring along the length of the cell that provides a 200 groundwater point sample slice along the streamtube of flow through the DNAPL source zone. TCE dechlorination is shown to be significant throughout the cell domain, but spatially heterogeneous in occurrence and progress of dechlorination to lesser chlorinated ethenes - it is this heterogeneity in dechlorination that we primarily scrutinise. We illustrate the diagnostic use of the relative occurrence of TCE parent and daughter compounds to confirm: dechlorination in close proximity to DNAPL and enhanced during the bioremediation; persistent layers of DNAPL into which gradients of dechlorination products are evident; fast flowpaths through the source zone where dechlorination is less evident; and, the importance of underpinning flow regime understanding on EISB performance. Still, even with such spatial detail, there remains uncertainty over the dataset interpretation. These includes poor closure of mass balance along the cell length for the multilevel sampler based monitoring and points to needs to still understand lateral flows (even in the constrained cell), even greater spatial resolution of point monitoring and potentially, not easily proven, ethene degradation loss.

  19. Ecogenomics of microbial communities in bioremediation of chlorinated contaminated sites

    OpenAIRE

    Maphosa, Farai; Shakti H Lieten; Dinkla, Inez; Stams, Alfons J.; Smidt, Hauke; Fennell, Donna E.

    2012-01-01

    Organohalide compounds such as chloroethenes, chloroethanes, and polychlorinated benzenes are among the most significant pollutants in the world. These compounds are often found in contamination plumes with other pollutants such as solvents, pesticides, and petroleum derivatives. Microbial bioremediation of contaminated sites, has become commonplace whereby key processes involved in bioremediation include anaerobic degradation and transformation of these organohalides by organohalide respirin...

  20. BIOREMEDIATION OF PETROLEUM HYDROCARBON CONTAMINANTS IN MARINE HABITATS

    Science.gov (United States)

    Bioremediation is being increasingly seen as an effective environmentally benign treatment for shorelines contaminated as a result of marine oil spills. Despite a relatively long history of research on oil-spill bioremediation, it remains an essentially empirical technology and m...

  1. Treatment of petroleum hydrocarbon polluted environment through bioremediation: a review.

    Science.gov (United States)

    Singh, Kriti; Chandra, Subhash

    2014-01-01

    Bioremediation play key role in the treatment of petroleum hydrocarbon contaminated environment. Exposure of petroleum hydrocarbon into the environment occurs either due to human activities or accidentally and cause environmental pollution. Petroleum hydrocarbon cause many toxic compounds which are potent immunotoxicants and carcinogenic to human being. Remedial methods for the treatment of petroleum contaminated environment include various physiochemical and biological methods. Due to the negative consequences caused by the physiochemical methods, the bioremediation technology is widely adapted and considered as one of the best technology for the treatment of petroleum contaminated environment. Bioremediation utilizes the natural ability of microorganism to degrade the hazardous compound into simpler and non hazardous form. This paper provides a review on the role of bioremediation in the treatment of petroleum contaminated environment, discuss various hazardous effects of petroleum hydrocarbon, various factors influencing biodegradation, role of various enzymes in biodegradation and genetic engineering in bioremediation.

  2. POTENTIAL FUNGI FOR BIOREMEDIATION OF INDUSTRIAL EFFLUENTS

    Directory of Open Access Journals (Sweden)

    Vara Saritha

    2010-02-01

    Full Text Available Two fungi (unidentified were isolated from soil and marine environ-ments. These isolates were used for bioremediation of pulp and paper mill effluent at the laboratory scale. The treatment resulted in the reduction of color, lignin, and COD of the effluent in the order of 78.6%, 79.0%, and 89.4% in 21 days. A major part of reductions in these parameters occurred within 5 days of the treatment, which was also characterized by a steep decline in the pH of the effluent. The enzyme activity of these fungi was also tested, and the clearance zone was obtained in the plate assay.

  3. POTENTIAL FUNGI FOR BIOREMEDIATION OF INDUSTRIAL EFFLUENTS

    OpenAIRE

    Vara Saritha; Avasn Maruthi; Mukkanti, K.

    2010-01-01

    Two fungi (unidentified) were isolated from soil and marine environ-ments. These isolates were used for bioremediation of pulp and paper mill effluent at the laboratory scale. The treatment resulted in the reduction of color, lignin, and COD of the effluent in the order of 78.6%, 79.0%, and 89.4% in 21 days. A major part of reductions in these parameters occurred within 5 days of the treatment, which was also characterized by a steep decline in the pH of the effluent. The enzyme activity of t...

  4. Bioremediation:A review of applications and problems to be resolved

    Institute of Scientific and Technical Information of China (English)

    ZHOU Qixing; HUA Tao

    2004-01-01

    This review article describes the factors affecting bioremediation processes including: goals of bioremediation and the optimal ecological conditions required; inoculation of microorganisms; cometabolism; bioavailability and its improvement; biological evolution and its utilization;monitoring and control of bioremediation processes; identification of bioremediation effectiveness and ecological remediation and its key elements. The current progress in bioremediation techniques is summarized. The direction of future development, research and applications is also examined.

  5. Actinobacteria: Current research and perspectives for bioremediation of pesticides and heavy metals.

    Science.gov (United States)

    Alvarez, Analia; Saez, Juliana Maria; Davila Costa, José Sebastian; Colin, Veronica Leticia; Fuentes, María Soledad; Cuozzo, Sergio Antonio; Benimeli, Claudia Susana; Polti, Marta Alejandra; Amoroso, María Julia

    2017-01-01

    Actinobacteria exhibit cosmopolitan distribution since their members are widely distributed in aquatic and terrestrial ecosystems. In the environment they play relevant ecological roles including recycling of substances, degradation of complex polymers, and production of bioactive molecules. Biotechnological potential of actinobacteria in the environment was demonstrated by their ability to remove organic and inorganic pollutants. This ability is the reason why actinobacteria have received special attention as candidates for bioremediation, which has gained importance because of the widespread release of contaminants into the environment. Among organic contaminants, pesticides are widely used for pest control, although the negative impact of these chemicals in the environmental balance is increasingly becoming apparent. Similarly, the extensive application of heavy metals in industrial processes lead to highly contaminated areas worldwide. Several studies focused in the use of actinobacteria for cleaning up the environment were performed in the last 15 years. Strategies such as bioaugmentation, biostimulation, cell immobilization, production of biosurfactants, design of defined mixed cultures and the use of plant-microbe systems were developed to enhance the capabilities of actinobacteria in bioremediation. In this review, we compiled and discussed works focused in the study of different bioremediation strategies using actinobacteria and how they contributed to the improvement of the already existing strategies. In addition, we discuss the importance of omic studies to elucidate mechanisms and regulations that bacteria use to cope with pollutant toxicity, since they are still little known in actinobacteria. A brief account of sources and harmful effects of pesticides and heavy metals is also given.

  6. Auto- and heterotrophic acidophilic bacteria enhance the bioremediation efficiency of sediments contaminated by heavy metals.

    Science.gov (United States)

    Beolchini, Francesca; Dell'Anno, Antonio; De Propris, Luciano; Ubaldini, Stefano; Cerrone, Federico; Danovaro, Roberto

    2009-03-01

    This study deals with bioremediation treatments of dredged sediments contaminated by heavy metals based on the bioaugmentation of different bacterial strains. The efficiency of the following bacterial consortia was compared: (i) acidophilic chemoautotrophic, Fe/S-oxidising bacteria, (ii) acidophilic heterotrophic bacteria able to reduce Fe/Mn fraction, co-respiring oxygen and ferric iron and (iii) the chemoautotrophic and heterotrophic bacteria reported above, pooled together, as it was hypothesised that the two strains could cooperate through a mutual substrate supply. The effect of the bioremediation treatment based on the bioaugmentation of Fe/S-oxidising strains alone was similar to the one based only on Fe-reducing bacteria, and resulted in heavy-metal extraction yields typically ranging from 40% to 50%. The efficiency of the process based only upon autotrophic bacteria was limited by sulphur availability. However, when the treatment was based on the addition of Fe-reducing bacteria and the Fe/S oxidizing bacteria together, their growth rates and efficiency in mobilising heavy metals increased significantly, reaching extraction yields >90% for Cu, Cd, Hg and Zn. The additional advantage of the new bioaugmentation approach proposed here is that it is independent from the availability of sulphur. These results open new perspectives for the bioremediation technology for the removal of heavy metals from highly contaminated sediments.

  7. Bioremediation of Carbendazim by Streptomyces albogriseolus

    Directory of Open Access Journals (Sweden)

    Ridhima Arya

    2014-08-01

    Full Text Available Carbendazim (methyl-1H-benzimidazol-2-ylcarbamate, or MBC is a benzimidazole fungicide which is used to protect crops against the attack of fungi. MBC has a half-life of about 3-12 months and remain persistent in the environment which may lead to many harmful consequences. Besides chemical and photo-catalytic degradation of pesticides, microbial degradation has now been evolved as a much effective and safer way to eliminate these harmful compounds from the environment. However, in the literature very few reports are available where microbial community is involved in degrading MBC. Hence, the present study was planned to investigate the role of microbes isolated from the field soils for the bioremediation of MBC. Soil samples were collected from wheat fields of northern regions of India. Enrichment culture technique was employed to isolate the bacterium which was found to be growing at higher concentrations of MBC up to 500µg/ml. After biochemical and morphological analysis, the bacterium was identified as Streptomyces albogriseolus. Streptomyces albogriseolus was found to degrade MBC in a time-dependent manner from the initial concentration of 29 ppm to 285.67ppb and 62.73ppb in 24hrs and 48hrs respectively. LCMS-MS analysis was carried out to detect 2-aminobenzimidazole, a metabolite formed after degradation in 10 hrs of growth which eventually disappeared after 24hrs of growth. The strain Streptomyces albogriseolus holds a promising potential to be an efficient MBC bioremediation agent.

  8. Bioremediation of marine sediments impacted by petroleum.

    Science.gov (United States)

    da Silva, Aike C; de Oliveira, Fernando J S; Bernardes, Diogo S; de França, Francisca P

    2009-05-01

    The aim of this work was to optimize the bioremediation of crude oil-contaminated sand sediment through the biostimulation technique. The soil was obtained in the mid-tide zone of Guanabara Bay, Rio de Janeiro, Brazil and was artificially contaminated with crude oil at 14 g kg(-1). Bioremediation optimization was performed using an experimental design and statistical analysis of the following factors: supplementation with commercial biosurfactant Jeneil IBR 425 and commercial mineral NPK fertilizer. The response variable used was the biodegradation of the heavy oil fraction, HOF. The analysis of the studied factors and their interactions was executed using contour plots, Pareto diagram and ANOVA table. Experimental design results indicated that the supplementation with fertilizer at 100:25:25 C/N/P ratio and biosurfactant at 2 g kg(-1) yielded biodegradation of HOF at about 30% during 30 days of process. Some experiments were carried out using the experimental design results, yielding 65% of biodegradation of HOF and 100% of n- alkanes between C15 and C30 during 60 process days. Intrinsic biodegradation test was carried out, yielding 85% of biodegradation of n-alkanes between C15 and C30 during 30 days of process.

  9. Influence of a precepitator on bioremedial processes

    Directory of Open Access Journals (Sweden)

    Nježić Zvonko B.

    2010-01-01

    Full Text Available Natural environment represents a dynamic bioreactor with numerous chemical, biochemical and microbiological processes through which harmful materials are destroyed, so that living organisms and human beings are not endanger. Controlled anthropogenic actions can assist the natural ecosystem to become an efficient bioremedial unit and to reduce the level of effluents produced in the biotechnological transformations during massive food production. In this study, a monitoring system for the chemical oxygen demand (COD and the heavy metal levels in water was established, followed by construction and building of a precipitator in order to prevent discharging of sludge. The results contribute to the hypothesis of existence of in situ bioremedial processes in the observed ecosystem. The significant influence of the precipitator on the decrease of pollution was demonstrated: a decrease of both the COD value and the heavy metal levels downstream from the precipitator for about 15%. Therefore it can be concluded that the precipitator significantly contributes to the ecosystem by the reduction of pollutant level.

  10. The Kwajalein bioremediation demonstration: Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Walker, J.R. Jr.; Walker, A.B.

    1994-12-01

    The US Army Kwajalein Atoll (USAKA) Base, located in the Republic of the Marshall Islands (RMI) in the east-central Pacific Ocean, has significant petroleum hydrocarbon contamination resulting from years of military activities. Because of its remoteness, the lack of on-site sophisticated remediation or waste disposal facilities, the amenability of petroleum hydrocarbons to biodegradation, and the year-round temperature favorable for microbial activity, USAKA requested, through the Hazardous Waste Remedial Actions Program (HAZWRAP), that a project be conducted to evaluate the feasibility of using bioremediation for environmental restoration of contaminated sites within the atoll. The project was conducted in four distinct phases: (1) initial site characterization and on-site biotreatability studies, (2) selection of the demonstration area and collection of soil columns, (3) laboratory column biotreatability studies, and (4) an on-site bioremediation demonstration. The results of phases (1) and (3) have been detailed in previous reports. This report summarizes the results of phases (1) and (3) and presents phases (2) and (4) in detail.

  11. Enrichment of specific protozoan populations during in situ bioremediation of uranium-contaminated groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Holmes, Dawn; Giloteaux, L.; Williams, Kenneth H.; Wrighton, Kelly C.; Wilkins, Michael J.; Thompson, Courtney A.; Roper, Thomas J.; Long, Philip E.; Lovley, Derek

    2013-07-28

    The importance of bacteria in the anaerobic bioremediation of groundwater polluted with organic and/or metal contaminants is well-recognized and in some instances so well understood that modeling of the in situ metabolic activity of the relevant subsurface microorganisms in response to changes in subsurface geochemistry is feasible. However, a potentially significant factor influencing bacterial growth and activity in the subsurface that has not been adequately addressed is protozoan predation of the microorganisms responsible for bioremediation. In field experiments at a uranium-contaminated aquifer located in Rifle, CO, acetate amendments initially promoted the growth of metal-reducing Geobacter species followed by the growth of sulfate-reducers, as previously observed. Analysis of 18S rRNA gene sequences revealed a broad diversity of sequences closely related to known bacteriovorous protozoa in the groundwater prior to the addition of acetate. The bloom of Geobacter species was accompanied by a specific enrichment of sequences most closely related to the amoeboid flagellate, Breviata anathema, which at their peak accounted for over 80% of the sequences recovered. The abundance of Geobacter species declined following the rapid emergence of B. anathema. The subsequent growth of sulfate-reducing Peptococcaceae was accompanied by another specific enrichment of protozoa, but with sequences most similar to diplomonadid flagellates from the family Hexamitidae, which accounted for up to 100% of the sequences recovered during this phase of the bioremediation. These results suggest a prey-predator response with specific protozoa responding to increased availability of preferred prey bacteria. Thus, quantifying the influence of protozoan predation on the growth, activity, and composition of the subsurface bacterial community is essential for predictive modeling of in situ uranium bioremediation strategies.

  12. Bioremediation Kinetics of Pharmaceutical Industrial Effluent

    Directory of Open Access Journals (Sweden)

    M. Šabić

    2015-05-01

    Full Text Available In recent years, concerns about the occurrence and fate of pharmaceuticals that could be present in water and wastewater has gained increasing attention. With the public’s enhanced awareness of eco-safety, environmentally benign methods based on microorganisms have become more accepted methods of removing pollutants from aquatic systems. This study investigates bioremediation of pharmaceutical wastewater from pharmaceutical company Pliva Hrvatska d.o.o., using activated sludge and bioaugmented activated sludge with isolated mixed bacterial culture. The experiments were conducted in a batch reactor in submerged conditions, at initial concentration of organic matter in pharmaceutical wastewater, expressed as COD, 5.01 g dm–3 and different initial concentrations of activated sludge, which ranged from 1.16 to 3.54 g dm–3. During the experiments, the COD, pH, concentrations of dissolved oxygen and biomass were monitored. Microscopic analyses were performed to monitor the quality of activated sludge. Before starting with the bioremediation in the batch reactor, toxicity of the pharmaceutical wastewater was determined by toxicity test using bacteria Vibrio fischeri. The obtained results showed that the effective concentration of the pharmaceutical wastewater was EC50 = 17 % and toxicity impact index was TII50 = 5.9, meaning that the untreated pharmaceutical industrial effluent must not be discharged into the environment before treatment. The results of the pharmaceutical wastewater bioremediation process in the batch reactor are presented in Table 1. The ratio γXv ⁄ γX maintained high values throughout all experiments and ranged from 0.90 and 0.95, suggesting that the concentrations of biomass remained unchanged during the experiments. The important kinetic parameters required for performance of the biological removal process, namely μmax, Ks, Ki, Y and kd were calculated from batch experiments (Table 2. Figs. 1 and 2 show the experimental

  13. Development and application of the lux gene for environmental bioremediation

    Science.gov (United States)

    Burlage, Robert S.; Yang, Zamin; Palmer, Robert J., Jr.; Sayler, Gary S.; Khang, Yongho

    1996-11-01

    Bioremediation is the use of living systems, usually microorganisms, to treat a quantity of soil or water for the presence of hazardous wastes. Bioremediation has many advantages over other remediation approaches, including cost savings, versatility, and the ability to treat the wastes in situ. In order to study the processes of microbial bioremediation, we have constructed bacterial strains that incorporate genetically engineered bioreporter genes. These bioreporter genes allow the bacteria to be detected during in situ processes, as manifested by their ability to bioluminesce or to fluoresce. This bioreporter microorganisms are described, along with the technology for detecting them and the projects which are benefiting from their application.

  14. Bioremediation techniques applied to aqueous media contaminated with mercury.

    Science.gov (United States)

    Velásquez-Riaño, Möritz; Benavides-Otaya, Holman D

    2016-12-01

    In recent years, the environmental and human health impacts of mercury contamination have driven the search for alternative, eco-efficient techniques different from the traditional physicochemical methods for treating this metal. One of these alternative processes is bioremediation. A comprehensive analysis of the different variables that can affect this process is presented. It focuses on determining the effectiveness of different techniques of bioremediation, with a specific consideration of three variables: the removal percentage, time needed for bioremediation and initial concentration of mercury to be treated in an aqueous medium.

  15. Development and application of the lux gene for environmental bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Burlage, R.S.; Yang, Z. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Palmer, R.J. [Univ. of Tennessee, Knoxville, TN (United States). Center for Environmental Biotechnology; Khang, Y. [Yeungnam Univ., Kyongsan (Korea, Republic of)

    1996-09-01

    Bioremediation is the use of living systems, usually microorganisms, to treat a quantity of soil or water for the presence of hazardous wastes. Bioremediation has many advantages over other remediation approaches, including cost savings, versatility, and the ability to treat the wastes in situ. In order to study the processes of microbial bioremediation, the authors have constructed bacterial strains that incorporate genetically engineered bioreporter genes. These bioreporter genes allow the bacteria to be detected during in situ processes, as manifested by their ability to bioluminescence or to fluoresce. This bioreporter microorganisms are described, along with the technology for detecting them and the projects which are benefiting from their application.

  16. Semifield testing of a bioremediation tool for atrazine-contaminated soils: evaluating the efficacy on soil and aquatic compartments.

    Science.gov (United States)

    Chelinho, Sónia; Moreira-Santos, Matilde; Silva, Cátia; Costa, Catarina; Viana, Paula; Viegas, Cristina A; Fialho, Arsénio M; Ribeiro, Rui; Sousa, José Paulo

    2012-07-01

    The present study evaluated the bioremediation efficacy of a cleanup tool for atrazine-contaminated soils (Pseudomonas sp. ADP plus citrate [P. ADP + CIT]) at a semifield scale, combining chemical and ecotoxicological information. Three experiments representing worst-case scenarios of atrazine contamination for soil, surface water (due to runoff), and groundwater (due to leaching) were performed in laboratory simulators (100 × 40 × 20 cm). For each experiment, three treatments were set up: bioremediated, nonbioremediated, and a control. In the first, the soil was sprayed with 10 times the recommended dose (RD) for corn of Atrazerba and with P. ADP + CIT at day 0 and a similar amount of P. ADP at day 2. The nonbioremediated treatment consisted of soil spraying with 10 times the RD of Atrazerba (day 0). After 7 d of treatment, samples of soil (and eluates), runoff, and leachate were collected for ecotoxicological tests with plants (Avena sativa and Brassica napus) and microalgae (Pseudokirchneriella subcapitata) species. In the nonbioremediated soils, atrazine was very toxic to both plants, with more pronounced effects on plant growth than on seed emergence. The bioremediation tool annulled atrazine toxicity to A. sativa (86 and 100% efficacy, respectively, for seed emergence and plant growth). For B. napus, results point to incomplete bioremediation. For the microalgae, eluate and runoff samples from the nonbioremediated soils were extremely toxic; a slight toxicity was registered for leachates. After only 7 d, the ecotoxicological risk for the aquatic compartments seemed to be diminished with the application of P. ADP + CIT. In aqueous samples obtained from the bioremediated soils, the microalgal growth was similar to the control for runoff samples and slightly lower than control (by 11%) for eluates.

  17. Robust hydrocarbon degradation and dynamics of bacterial communities during nutrient-enhanced oil spill bioremediation.

    Science.gov (United States)

    Röling, Wilfred F M; Milner, Michael G; Jones, D Martin; Lee, Kenneth; Daniel, Fabien; Swannell, Richard J P; Head, Ian M

    2002-11-01

    Degradation of oil on beaches is, in general, limited by the supply of inorganic nutrients. In order to obtain a more systematic understanding of the effects of nutrient addition on oil spill bioremediation, beach sediment microcosms contaminated with oil were treated with different levels of inorganic nutrients. Oil biodegradation was assessed respirometrically and on the basis of changes in oil composition. Bacterial communities were compared by numerical analysis of denaturing gradient gel electrophoresis (DGGE) profiles of PCR-amplified 16S rRNA genes and cloning and sequencing of PCR-amplified 16S rRNA genes. Nutrient amendment over a wide range of concentrations significantly improved oil degradation, confirming that N and P limited degradation over the concentration range tested. However, the extent and rate of oil degradation were similar for all microcosms, indicating that, in this experiment, it was the addition of inorganic nutrients rather than the precise amount that was most important operationally. Very different microbial communities were selected in all of the microcosms. Similarities between DGGE profiles of replicate samples from a single microcosm were high (95% +/- 5%), but similarities between DGGE profiles from replicate microcosms receiving the same level of inorganic nutrients (68% +/- 5%) were not significantly higher than those between microcosms subjected to different nutrient amendments (63% +/- 7%). Therefore, it is apparent that the different communities selected cannot be attributed to the level of inorganic nutrients present in different microcosms. Bioremediation treatments dramatically reduced the diversity of the bacterial community. The decrease in diversity could be accounted for by a strong selection for bacteria belonging to the alkane-degrading Alcanivorax/Fundibacter group. On the basis of Shannon-Weaver indices, rapid recovery of the bacterial community diversity to preoiling levels of diversity occurred. However, although

  18. Ecogenomics of microbial communities in bioremediation of chlorinated contaminated sites

    NARCIS (Netherlands)

    Maphosa, F.; Lieten, S.; Dinkla, I.; Stams, A.J.M.; Fennel, D.E.

    2012-01-01

    Organohalide compounds such as chloroethenes, chloroethanes, and polychlorinated benzenes are among the most significant pollutants in the world. These compounds are often found in contamination plumes with other pollutants such as solvents, pesticides, and petroleum derivatives. Microbial bioremedi

  19. DEMONSTRATION BULLETIN: GRACE DEARBORN INC. DARAMEND™ BIOREMEDIATION TECHNOLOGY

    Science.gov (United States)

    The DARAMEND™ Bioremediation Technology may be applied to the remediation of soils and sediments contaminated by a wide variety of organic contaminants including chlorinated phenols, polynuclear aromatic hydrocarbons (PAHs), and petroleum hydrocarbons. The technology may be ap...

  20. Bioremediation of chlorinated ethenes in aquifer thermal energy storage

    NARCIS (Netherlands)

    Ni, Z.

    2015-01-01

      Subjects: bioremediation; biodegradation; environmental biotechnology, subsurface and groundwater contamination; biological processes; geochemistry; microbiology The combination of enhanced natural attenuation (ENA) of chlorinated volatile organic compounds (CVOCs) and aquife

  1. Bioremediation of oil-contaminated soils: A recipe for success

    Energy Technology Data Exchange (ETDEWEB)

    Wittenbach, S.A.

    1995-12-31

    Bioremediation of land crude oil and lube oil spills is an effective and economical option. Other options include road spreading (where permitted), thermal desorption, and off-site disposal. The challenge for environment and operations managers is to select the best approach for each remediation site. Costs and liability for off-site disposal are ever increasing. Kerr-McGee`s extensive field research in eastern and western Texas provides the data to support bioremediation as a legitimate and valid option. Both practical and economical bioremediation as a legitimate and valid option. Both practical and economical, bioremediation also offers a lower risk of, for example, Superfund clean-up exposure than off-site disposal.

  2. Heavy Metal Polluted Soils: Effect on Plants and Bioremediation Methods

    Directory of Open Access Journals (Sweden)

    G. U. Chibuike

    2014-01-01

    Full Text Available Soils polluted with heavy metals have become common across the globe due to increase in geologic and anthropogenic activities. Plants growing on these soils show a reduction in growth, performance, and yield. Bioremediation is an effective method of treating heavy metal polluted soils. It is a widely accepted method that is mostly carried out in situ; hence it is suitable for the establishment/reestablishment of crops on treated soils. Microorganisms and plants employ different mechanisms for the bioremediation of polluted soils. Using plants for the treatment of polluted soils is a more common approach in the bioremediation of heavy metal polluted soils. Combining both microorganisms and plants is an approach to bioremediation that ensures a more efficient clean-up of heavy metal polluted soils. However, success of this approach largely depends on the species of organisms involved in the process.

  3. Guidelines for the Bioremediation of Marine Shorelines and Freshwater Wetlands

    Science.gov (United States)

    For oil spill responders:presents rational approach, evaluates current practices and state-of-the-art research results pertaining to bioremediation of hydrocarbon contamination relative to types and amounts of amendments used, application frequency, extent

  4. The role of soil hydrologic heterogeneity for modeling large-scale bioremediation protocols.

    Science.gov (United States)

    Romano, N.; Palladino, M.; Speranza, G.; Di Fiore, P.; Sica, B.; Nasta, P.

    2014-12-01

    The major aim of the EU-Life+ project EcoRemed (Implementation of eco-compatible protocols for agricultural soil remediation in Litorale Domizio-Agro Aversano NIPS) is the implementation of operating protocols for agriculture-based bioremediation of contaminated croplands, which also involves plants extracting pollutants being then used as biomasses for renewable energy production. The study area is the National Interest Priority Site (NIPS) called Litorale Domitio-Agro Aversano, which is located in the Campania Region (Southern Italy) and has an extent of about 200,000 ectars. In this area, a high-level spotted soil contamination is mostly due to the legal or outlaw industrial and municipal wastes, with hazardous consequences also on the quality of the groundwater. An accurate determination of the soil hydraulic properties to characterize the landscape heterogeneity of the study area plays a key role within the general framework of this project, especially in view of the use of various modeling tools for water flow and solute transport simulations and to predict the effectiveness of the adopted bioremediation protocols. The present contribution is part of an ongoing study where we are investigating the following research questions: a) Which spatial aggregation schemes seem more suitable for upscaling from point to block support? b) Which effective soil hydrologic characteristic schemes simulate better the average behavior of larger scale phytoremediation processes? c) Allowing also for questions a) and b), how the spatial variability of soil hydraulic properties affect the variability of plant responses to hydro-meteorological forcing?

  5. Bioremediation of PCBs. CRADA final report

    Energy Technology Data Exchange (ETDEWEB)

    Klasson, K.T. [Oak Ridge National Lab., TN (United States). Chemical Technology Div., TN (United States); Abramowicz, D.A. [General Electric Co. Corporate Research and Development, Niskayuna, NY (United States)

    1996-06-01

    The Cooperative Research and Development Agreement was signed between Oak Ridge National Laboratory (ORNL) and General Electric Company (GE) on August 12, 1991. The objective was a collaborative venture between researchers at GE and ORNL to develop bioremediation of polychlorinated biphenyls (PCBs). The work was conducted over three years, and this report summarizes ORNL`s effort. It was found that the total concentration of PCBs decreased by 70% for sequential anaerobic-aerobic treatment compared with a 67% decrease for aerobic treatment alone. The sequential treatment resulted in PCB products with fewer chlorines and shorter halflives in humans compared with either anaerobic or aerobic treatment alone. The study was expected to lead to a technology applicable to a field experiment that would be performed on a DOE contaminated site.

  6. ENHANCING STAKEHOLDER ACCEPTANCE OF BIOREMEDIATION TECHNOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    Focht, Will; Albright, Matt; Anex, Robert P., Jr., ed.

    2009-04-21

    This project inquired into the judgments and beliefs of people living near DOE reservations and facilities at Oak Ridge, Tennessee; Hanford, Washington; and Los Alamos, Tennessee about bioremediation of subsurface contamination. The purpose of the investigation was to identify strategies based on these judgments and beliefs for enhancing public support of bioremediation. Several methods were used to collect and analyze data including content analysis of transcripts of face-to-face personal interviews, factor analysis of subjective perspectives using Q methodology, and statistical analysis of results from a large-sample randomized telephone survey. Content analysis of interview transcripts identified themes about public perceptions and constructions of contamination risk, risk management, and risk managers. This analysis revealed that those who have no employment relationship at the sites and are not engaged in technical professions are most concerned about contamination risks. We also found that most interviewees are unfamiliar with subsurface contamination risks and how they can be reduced, believe they have little control over exposure, are frustrated with the lack of progress in remediation, are concerned about a lack of commitment of DOE to full remediation, and distrust site managers to act in the public interest. Concern is also expressed over frequent site management turnover, excessive secrecy, ineffective and biased communication, perceived attempts to talk the public into accepting risk, and apparent lack of concern about community welfare. In the telephone survey, we asked respondents who were aware of site contamination about their perceptions of risk from exposure to subsurface contamination. Response analysis revealed that most people believe that they are at significant risk from subsurface contamination but they acknowledge that more education is needed to calibrate risk perceptions against scientific risk assessments. Most rate their personal

  7. Optimal conditions for bioremediation of oily seawater.

    Science.gov (United States)

    Zahed, Mohammad Ali; Aziz, Hamidi Abdul; Isa, Mohamed Hasnain; Mohajeri, Leila; Mohajeri, Soraya

    2010-12-01

    To determine the influence of nutrients on the rate of biodegradation, a five-level, three-factor central composite design (CCD) was employed for bioremediation of seawater artificially contaminated with crude oil. Removal of total petroleum hydrocarbons (TPH) was the dependent variable. Samples were extracted and analyzed according to US-EPA protocols. A significant (R(2)=0.9645, P<0.0001) quadratic polynomial mathematical model was generated. Removal from samples not subjected to optimization and removal by natural attenuation were 53.3% and 22.6%, respectively. Numerical optimization was carried out based on desirability functions for maximum TPH removal. For an initial crude oil concentration of 1g/L supplemented with 190.21 mg/L nitrogen and 12.71 mg/L phosphorus, the Design-Expert software predicted 60.9% hydrocarbon removal; 58.6% removal was observed in a 28-day experiment.

  8. Bioremediation: Copper Nanoparticles from Electronic-waste

    Directory of Open Access Journals (Sweden)

    D. R. MAJUMDER

    2012-10-01

    Full Text Available A single-step eco-friendly approach has been employed to synthesize copper nanoparticles. The superfast advancement in the field of electronics has given rise to a new type of waste called electronic waste. Since the physical and chemical recycling procedures have proved to be hazardous, the present work aims at the bioremediation of e-waste in order to recycle valuable metals. Microorganisms such as Fusarium oxysporum and Pseudomonas sp. were able to leach copper (84-130 nm from integrated circuits present on electronic boards under ambient conditions. Lantana camara, a weed commonly found in Maharashtra was also screened for leaching copper. The characteristics of the copper nanoparticles obtained were studied using X-ray diffraction analysis, energy-dispersive spectroscopy, scanning electron microscopy, Fourier Tranform Infrared analysis, Transmission electron microscopy, Thermogravimetric analysis and Cyclic Voltammetry. Copper nanoparticles were found to be effective against hospital strain Escherichia coli 2065.

  9. Healthy environments for healthy people: bioremediation today and tomorrow.

    OpenAIRE

    Bonaventura, C; Johnson, F. M.

    1997-01-01

    Increases in environmental contamination lead to a progressive deterioration of environmental quality. This condition challenges our global society to find effective measures of remediation to reverse the negative conditions that severely threaten human and environmental health. We discuss the progress being made toward this goal through application of bioremediation techniques. Bioremediation generally utilizes microbes (bacteria, fungi, yeast, and algae), although higher plants are used in ...

  10. Bioremediation, an environmental remediation technology for the bioeconomy.

    Science.gov (United States)

    Gillespie, Iain M M; Philp, Jim C

    2013-06-01

    Bioremediation differs from other industrial biotechnologies in that, although bioremediation contractors must profit from the activity, the primary driver is regulatory compliance rather than manufacturing profit. It is an attractive technology in the context of a bioeconomy but currently has limitations at the field scale. Ecogenomics techniques may address some of these limitations, but a further challenge would be acceptance of these techniques by regulators.

  11. Development of combinatorial bacteria for metal and radionuclide bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    A. C. Matin, Ph. D.

    2006-06-15

    The grant concerned chromate [Cr(VI)] bioremediation and it was our aim from the outset to construct individual bacterial strains capable of improved bioremediation of multiple pollutants and to identify the enzymes suited to this end. Bacteria with superior capacity to remediate multiple pollutants can be an asset for the cleanup of DOE sites as they contain mixed waste. I describe below the progress made during the period of the current grant, providing appropriate context.

  12. Effectiveness of bioremediation for the Exxon Valdez oil spill

    Science.gov (United States)

    Bragg, James R.; Prince, Roger C.; Harner, E. James; Atlas, Ronald M.

    1994-03-01

    The effectiveness of bioremediation for oil spills has been difficult to establish on dynamic, heterogeneous marine shorelines. A new interpretative technique used following the 1989 Exxon Valdez spill in Alaska shows that fertilizer applications significantly increased rates of oil biodegradation. Biodegradation rates depended mainly on the concentration of nitrogen within the shoreline, the oil loading, and the extent to which natural biodegradation had already taken place. The results suggest ways to improve the effectiveness of bioremediation measures in the future.

  13. Field Implementation of Bioremediation at INDOT Facilities-Phase I

    OpenAIRE

    Nies, Loring F.; Baldwin, Brett Robert; Mesarch, Matthew B.

    2000-01-01

    Bioremediation is often the most cost-effective and successful technique available for the remediation of soils and groundwater contaminated with organic pollutants (e.g. petroleum). The goal of bioremediation is to stimulate naturally occurring microorganisms to biodegrade the contaminants to harmless products. To be in compliance with EPA regulations all underground fuel storage tanks must have spill, leak and corrosion protection. Many older obsolete tanks had deteriorated to the extent th...

  14. A new technique of solar bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Chaalal, O. [University General Requirements Unit, UAE University, Abu Dhabi (United Arab Emirates); Tango, M.; Islam, M. [Dalhousie Univ., Halifax, NS (Canada)

    2005-03-15

    Disinfection with solar energy has been in practice for centuries. This article uses this old technology and builds on some of its unique features in order to develop an effective method of bioremediation. Recently, a strain of thermophilic bacteria was isolated from the environment of the United Arab Emirates. These bacteria show extraordinary resistance to heat and have their maximum growth rate around 80{sup o}C. They are found to be extremely efficient in remediating petroleum contaminants in the presence of high salinity water (simulated seawater). This article investigates the potential of using these facultative bacteria in a bioreactor in conjunction with solar irradiation. The bioreactor, recently developed at the UAE University, uses air flow through a transverse perforated pipe in order to create effective mixing, leading to optimum growth environment for bacteria. Solar energy is used in two ways. UV radiation from the sun destroys most pathogens and creates an environment that offers little competition for the thermophilic bacteria that cannot be destroyed with the UV. Also, the second advantage of the solar energy is the increase in temperature of the reactor water to a level that is more suitable for growth of the thermophilic bacteria. Heat also decreases the viscosity and interfacial tension of the petroleum contaminant, leading to the profuse emulsification. Emulsification makes more bacteria available to the petroleum contaminant and enhances bioremediation. Detailed pictorial visualization performed with a computer image analyzer showed the extinction of bacteria other than the useful thermophilic bacteria and helped measure their growth. Finally, mathematical models are developed for determining the degradation rate in the presence of solar exposure. Corrections are made to accommodate both the effects of temperature, salinity, and solar intensity. To the best of the knowledge of the authors, this coupling has not been done before. Predictive

  15. Endophytic microorganisms--promising applications in bioremediation of greenhouse gases.

    Science.gov (United States)

    Stępniewska, Z; Kuźniar, A

    2013-11-01

    Bioremediation is a technique that uses microbial metabolism to remove pollutants. Various techniques and strategies of bioremediation (e.g., phytoremediation enhanced by endophytic microorganisms, rhizoremediation) can mainly be used to remove hazardous waste from the biosphere. During the last decade, this specific technique has emerged as a potential cleanup tool only for metal pollutants. This situation has changed recently as a possibility has appeared for bioremediation of other pollutants, for instance, volatile organic compounds, crude oils, and radionuclides. The mechanisms of bioremediation depend on the mobility, solubility, degradability, and bioavailability of contaminants. Biodegradation of pollutions is associated with microbial growth and metabolism, i.e., factors that have an impact on the process. Moreover, these factors have a great influence on degradation. As a result, recognition of natural microbial processes is indispensable for understanding the mechanisms of effective bioremediation. In this review, we have emphasized the occurrence of endophytic microorganisms and colonization of plants by endophytes. In addition, the role of enhanced bioremediation by endophytic bacteria and especially of phytoremediation is presented.

  16. Impact of organic carbon and nutrients mobilized during chemical oxidation on subsequent bioremediation of a diesel-contaminated soil.

    Science.gov (United States)

    Sutton, Nora B; Grotenhuis, Tim; Rijnaarts, Huub H M

    2014-02-01

    Remediation with in situ chemical oxidation (ISCO) impacts soil organic matter (SOM) and the microbial community, with deleterious effects on the latter being a major hurdle to coupling ISCO with in situ bioremediation (ISB). We investigate treatment of a diesel-contaminated soil with Fenton's reagent and modified Fenton's reagent coupled with a subsequent bioremediation phase of 187d, both with and without nutrient amendment. Chemical oxidation mobilized SOM into the liquid phase, producing dissolved organic carbon (DOC) concentrations 8-16 times higher than the untreated field sample. Higher aqueous concentrations of nitrogen and phosphorous species were also observed following oxidation; NH4(+) increased 14-172 times. During the bioremediation phase, dissolved carbon and nutrient species were utilized for microbial growth-yielding DOC concentrations similar to field sample levels within 56d of incubation. In the absence of nutrient amendment, the highest microbial respiration rates were correlated with higher availability of nitrogen and phosphorus species mobilized by oxidation. Significant diesel degradation was only observed following nutrient amendment, implying that nutrients mobilized by chemical oxidation can increase microbial activity but are insufficient for bioremediation. While all bioremediation occurred in the first 28d of incubation in the biotic control microcosm with nutrient amendment, biodegradation continued throughout 187d of incubation following chemical oxidation, suggesting that chemical treatment also affects the desorption of organic contaminants from SOM. Overall, results indicate that biodegradation of DOC, as an alternative substrate to diesel, and biological utilization of mobilized nutrients have implications for the success of coupled ISCO and ISB treatments.

  17. Bioremediation Well Borehole Soil Sampling and Data Analysis Summary Report for the 100-N Area Bioremediation Project

    Energy Technology Data Exchange (ETDEWEB)

    D. A. Gamon

    2009-09-28

    The purpose of this report is to present data and findings acquired during the drilling and construction of seven bioremediation wells in the 100-N Area in conjunction with remediation of the UPR-100-N-17 petroleum waste site.

  18. Laboratory experiment on bioremediation of crude oil by microbial consortium

    Energy Technology Data Exchange (ETDEWEB)

    Bao, M.; Wang, L. [Ocean Univ. of China, Qingdao, Shandong (China); Cao, L.; Sun, P. [State Ocean Administration, Qingdao, Shandong (China). North China Sea Environmental Monitoring Center

    2009-07-01

    Bioremediation has been touted as a promising method to remove oil from seawater. Studies have shown that 4 bacteria N1, N2, N3 and N4, isolated from seawater and oil-polluted coastal sediments in Qingdao Port, have a strong ability to degrade crude oil. Laboratory-scale experiments were conducted based on the microbial remediation functions of the bacterium flora. This paper reported on a study in which shake flask experiments were used to investigate the degradation conditions of the 4 strains. The flask tests were followed by small model basin tests where 4 strains were applied to the simulated marine environment. In the model basin test, the biodegradation rate reached 86.22 per cent. In the simulation experiment, the crude oil was analyzed by gas chromatography before and after biodegradation. The study showed that shake flask experiments provided better biodegradation conditions for the bacteria, resulting in high degradation rates. The 3 stages of laboratory-scale studies produced very similar biodegradation trends, although the degradation rate decreased slightly. It was concluded that the predominant flora chosen for this study may be feasible in treating contaminated sea water. 19 refs., 1 tab., 6 figs.

  19. ENHANCING STAKEHOLDER ACCEPTANCE OF BIOREMEDIATION TECHNOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    Focht, Will; Albright, Matt; Anex, Robert P., Jr., ed.

    2009-04-21

    This project inquired into the judgments and beliefs of people living near DOE reservations and facilities at Oak Ridge, Tennessee; Hanford, Washington; and Los Alamos, Tennessee about bioremediation of subsurface contamination. The purpose of the investigation was to identify strategies based on these judgments and beliefs for enhancing public support of bioremediation. Several methods were used to collect and analyze data including content analysis of transcripts of face-to-face personal interviews, factor analysis of subjective perspectives using Q methodology, and statistical analysis of results from a large-sample randomized telephone survey. Content analysis of interview transcripts identified themes about public perceptions and constructions of contamination risk, risk management, and risk managers. This analysis revealed that those who have no employment relationship at the sites and are not engaged in technical professions are most concerned about contamination risks. We also found that most interviewees are unfamiliar with subsurface contamination risks and how they can be reduced, believe they have little control over exposure, are frustrated with the lack of progress in remediation, are concerned about a lack of commitment of DOE to full remediation, and distrust site managers to act in the public interest. Concern is also expressed over frequent site management turnover, excessive secrecy, ineffective and biased communication, perceived attempts to talk the public into accepting risk, and apparent lack of concern about community welfare. In the telephone survey, we asked respondents who were aware of site contamination about their perceptions of risk from exposure to subsurface contamination. Response analysis revealed that most people believe that they are at significant risk from subsurface contamination but they acknowledge that more education is needed to calibrate risk perceptions against scientific risk assessments. Most rate their personal

  20. Rehabilitation of oil polluted soils by bioremediation

    Science.gov (United States)

    Dumitru, Mihail; Parvan, Lavinia; Cioroianu, Mihai; Carmen, Sirbu; Constantin, Carolina

    2015-04-01

    In Romania about 50,000 ha are polluted with oil and/or brine. The main sources of pollution are the different activities using petroleum products: extraction, transport, treatment, refining and distribution. Taking into acoount the large areas and the cost per unit area, bioremediation was tested as a method of rehabilitation. To stimulate the performance of the bioremediation process for a polluted soil (luvisol) by 3% oil, different methods were tested: -application of a bacterial inoculum consisting of species of the Pseudomonas and Arthrobacter genera;- application of two types of absorbent materials, 16 t/ha peat and 16, respectively, 32 kg/ha Zeba (starch-based polymer, superabsorbent); -mineral fertilization with N200P200K200 and 5 different liquid fertilizer based on potassium humates extracted from lignite in a NPK matrix with micronutrients and added monosaccharides (4 and 8%). After 45 days from the treatment (60 days from pollution) the following observations have been noticed: • the application of only bacterial inoculum had no significant effect on the degradation of petroleum hydrocarbons; • the use of 650 l/ha AH-SH fertilizer (potassium humate in a NPK matrix) led to a 47% decrease of TPH (total petroleum hydrocarbons); • the application of 16 t/ha peat, together with the bacterial inoculum and the AH-SG2 liquid fertilizer (containing humates of potassium in a NPK matrix with microelements and 8% monosaccharides, in which the nitrogen is amide form) led to a 50% decrease of the TPH content; • the application of 16 kg/ha Zeba absorbent together with bacterial inoculum and 650 l/ha AH-SG1 liquid fertilizer (containing humates of potassium in a NPK matrix with microelements and 4% monosaccharide in which the nitrogen is in amide form) led to a 57% decrease of the TPH content; • the application of 32 kg/ha Zeba absorbent, together with the AH-SG2 fertilizer, led to a 58% decrease of the TPH content.

  1. Hydrogen as an Indicator to Assess Biological Activity During Trace-Metal Bioremediation

    Science.gov (United States)

    Jaffe, P. R.; Komlos, J.; Brown, D. G.; Lovley, D. R.

    2002-05-01

    The design and operation of a trace-metal or radionuclide bioremediation scheme requires that specific redox conditions be achieved at given zones of an aquifer for a predetermined duration. Tools are therefore needed to identify and quantify the terminal electron acceptor processes (TEAPs) that are being achieved during bioremediation in an aquifer, and that this is done at a high spatial resolution. Hydrogen holds the promise of being a key parameter that may be used to identify TEAPs. Theoretical analysis have shown that steady-state hydrogen levels in the subsurface are solely dependent upon the physiological parameters of the hydrogen-consuming microorganisms, and that hydrogen concentrations increase as each successive TEAP yields less energy for bacterial growth. The assumptions for this statement may not hold during a bioremediation scheme in which an organic substrate is injected into the subsurface and where organisms may consume hydrogen and carbon simultaneously. The objective of the research is to gain a basic understanding of the hydrogen dynamics in an aquifer during a trace metal/radionuclide bioremediation scheme. For this purpose, a series of batch studies have been conducted during the first year of this project. In these studies the utilization of acetate and hydrogen by geobacter sulfurreducens were studied. In all cases Fe(III) was the electron acceptor. Microcosms were set up to investigate the utilization of hydrogen and acetate when either of them is the sole electron donor and when both are present and utilized simultaneously as electron donor. These experiments were conducted for varying initial conditions of the hydrogen and acetate concentration, and the disappearance of these compounds plus the evolution of Fe(II) as well as biomass was monitored over time. The results of these studies indicate that the biokinetic coefficients describing the rate of hydrogen utilization are not affected by the simultaneous utilization of acetate. While

  2. The development and application of engineered proteins for bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Trewhella, J. [ed.

    1995-09-26

    Clean up of the toxic legacy of the Cold War is projected to be the most expensive domestic project the nation has yet undertaken. Remediation of the Department of Energy and Department of Defense toxic waste sites alone are projected to cost {approximately}$1 trillion over a 20-30 year period. New, cost effective technologies are needed to attack this enormous problem. Los Alamos has put together a cross-divisional team of scientist to develop science based bioremediation technology to work toward this goal. In the team we have expertise in: (1) molecular, ecosystem and transport modeling; (2) genetic and protein engineering; (3) microbiology and microbial ecology; (4) structural biology; and (5) bioinorganic chemistry. This document summarizes talks at a workshop of different aspects of bioremediation technology including the following: Introducing novel function into a Heme enzyme: engineering by excavation; cytochrome P-450: ideal systems for bioremediation?; selection and development of bacterial strains for in situ remediation of cholorinated solvents; genetic analysis and preparation of toluene ortho-monooxygenase for field application in remediation of trichloroethylene; microbial ecology and diversity important to bioremediation; engineering haloalkane dehalogenase for bioremediation; enzymes for oxidative biodegradation; indigenous bacteria as hosts for engineered proteins; performance of indigenous bacterial, hosting engineered proteins in microbial communities.

  3. Bioremediation treatment of hydrocarbon-contaminated Arctic soils: influencing parameters.

    Science.gov (United States)

    Naseri, Masoud; Barabadi, Abbas; Barabady, Javad

    2014-10-01

    The Arctic environment is very vulnerable and sensitive to hydrocarbon pollutants. Soil bioremediation is attracting interest as a promising and cost-effective clean-up and soil decontamination technology in the Arctic regions. However, remoteness, lack of appropriate infrastructure, the harsh climatic conditions in the Arctic and some physical and chemical properties of Arctic soils may reduce the performance and limit the application of this technology. Therefore, understanding the weaknesses and bottlenecks in the treatment plans, identifying their associated hazards, and providing precautionary measures are essential to improve the overall efficiency and performance of a bioremediation strategy. The aim of this paper is to review the bioremediation techniques and strategies using microorganisms for treatment of hydrocarbon-contaminated Arctic soils. It takes account of Arctic operational conditions and discusses the factors influencing the performance of a bioremediation treatment plan. Preliminary hazard analysis is used as a technique to identify and assess the hazards that threaten the reliability and maintainability of a bioremediation treatment technology. Some key parameters with regard to the feasibility of the suggested preventive/corrective measures are described as well.

  4. Predicting bioremediation of hydrocarbons: laboratory to field scale.

    Science.gov (United States)

    Diplock, E E; Mardlin, D P; Killham, K S; Paton, G I

    2009-06-01

    There are strong drivers to increasingly adopt bioremediation as an effective technique for risk reduction of hydrocarbon impacted soils. Researchers often rely solely on chemical data to assess bioremediation efficiently, without making use of the numerous biological techniques for assessing microbial performance. Where used, laboratory experiments must be effectively extrapolated to the field scale. The aim of this research was to test laboratory derived data and move to the field scale. In this research, the remediation of over thirty hydrocarbon sites was studied in the laboratory using a range of analytical techniques. At elevated concentrations, the rate of degradation was best described by respiration and the total hydrocarbon concentration in soil. The number of bacterial degraders and heterotrophs as well as quantification of the bioavailable fraction allowed an estimation of how bioremediation would progress. The response of microbial biosensors proved a useful predictor of bioremediation in the absence of other microbial data. Field-scale trials on average took three times as long to reach the same endpoint as the laboratory trial. It is essential that practitioners justify the nature and frequency of sampling when managing remediation projects and estimations can be made using laboratory derived data. The value of bioremediation will be realised when those that practice the technology can offer transparent lines of evidence to explain their decisions.

  5. Fungal Laccases and Their Applications in Bioremediation

    Directory of Open Access Journals (Sweden)

    Buddolla Viswanath

    2014-01-01

    Full Text Available Laccases are blue multicopper oxidases, which catalyze the monoelectronic oxidation of a broad spectrum of substrates, for example, ortho- and para-diphenols, polyphenols, aminophenols, and aromatic or aliphatic amines, coupled with a full, four-electron reduction of O2 to H2O. Hence, they are capable of degrading lignin and are present abundantly in many white-rot fungi. Laccases decolorize and detoxify the industrial effluents and help in wastewater treatment. They act on both phenolic and nonphenolic lignin-related compounds as well as highly recalcitrant environmental pollutants, and they can be effectively used in paper and pulp industries, textile industries, xenobiotic degradation, and bioremediation and act as biosensors. Recently, laccase has been applied to nanobiotechnology, which is an increasing research field, and catalyzes electron transfer reactions without additional cofactors. Several techniques have been developed for the immobilization of biomolecule such as micropatterning, self-assembled monolayer, and layer-by-layer techniques, which immobilize laccase and preserve their enzymatic activity. In this review, we describe the fungal source of laccases and their application in environment protection.

  6. Method for phosphate-accelerated bioremediation

    Science.gov (United States)

    Looney, Brian B.; Lombard, Kenneth H.; Hazen, Terry C.; Pfiffner, Susan M.; Phelps, Tommy J.; Borthen, James W.

    1996-01-01

    An apparatus and method for supplying a vapor-phase nutrient to contaminated soil for in situ bioremediation. The apparatus includes a housing adapted for containing a quantity of the liquid nutrient, a conduit in fluid communication with the interior of the housing, means for causing a gas to flow through the conduit, and means for contacting the gas with the liquid so that a portion thereof evaporates and mixes with the gas. The mixture of gas and nutrient vapor is delivered to the contaminated site via a system of injection and extraction wells configured to the site. The mixture has a partial pressure of vaporized nutrient that is no greater than the vapor pressure of the liquid. If desired, the nutrient and/or the gas may be heated to increase the vapor pressure and the nutrient concentration of the mixture. Preferably, the nutrient is a volatile, substantially nontoxic and nonflammable organic phosphate that is a liquid at environmental temperatures, such as triethyl phosphate or tributyl phosphate.

  7. Optimized Enhanced Bioremediation Through 4D Geophysical Monitoring and Autonomous Data Collection, Processing and Analysis

    Science.gov (United States)

    2014-09-01

    ER-200717) Optimized Enhanced Bioremediation Through 4D Geophysical Monitoring and Autonomous Data Collection, Processing and Analysis...N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Optimized Enhanced Bioremediation Through 4D Geophysical Monitoring and Autonomous Data...8 2.1.2 The Geophysical Signatures of Bioremediation ......................................... 8 2.2 PRIOR

  8. Application of Fingerprinting Molecular Methods in Bioremediation Studies

    Science.gov (United States)

    Karpouzas, Dimitrios G.; Singh, Brajesh K.

    Bioremediation has been identified as a beneficial and effective strategy for the removal of recalcitrant environmental contaminants. Bioaugmentation of polluted environments with exogenous degrading microorganisms constitutes a major strategy of bioremediation. However, the ecological role of these strains and their impact on the endogenous microbial community of the micro-ecosystems where they are released should be known. Fingerprinting PCR-based methods, like denaturating gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism (TRFLP), could be used in studies exploring the ecology of pollutant-degrading microorganisms and their effects on the structure of the soil microbial community. This chapter provides a brief outline of the technical details involved in the application of DGGE and TRFLP fingerprinting in soil microbial ecology, with particular reference to bioremediation studies.

  9. Biosurfactant-enhanced bioremediation of polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Cameotra, S.S.; Bollag, J.M. [Penn State University, University Park, PA (USA). Soil Biochemical Lab.

    2003-07-01

    Biosurfactants are surface-active compounds synthesized by it wide variety of micro-organisms. They are molecules that have both hydrophobic and hydrophilic domains and are capable of lowering the surface tension and the interfacial tension of the growth medium. Biosurfactants possess different chemical structures - lipopeptides, glycolipids, neutral lipids, and fatty acids. They are nontoxic biomolecules that are biodegradable. Biosurfactants also exhibit strong emulsification of hydrophobic compounds and form stable emulsions. Polycyclic aromatic hydrocarbons (PAHs) can be toxic, mutagenic, and carcinogenic compounds that pollute the environment. They are released to the environment its a result of spillage of oil and byproducts of coal treatment processes. The low water solubility of PAHs limits their availability to microorganisms, which is a potential problem for bioremediation of PAH-contaminated sites. Microbially produced surfactants enhance the bioavailability of these hydrophobic compounds for bioremediation. Therefore, biosurfactant-enhanced solubility of PAHs has potential applications in bioremediation.

  10. Bioremediation of soluble heavy metals with recombinant Caulobacter crescentus.

    Science.gov (United States)

    Xu, Zhaohui; Lei, Yu; Patel, Jigar

    2010-01-01

    To achieve one-step separation of heavy metal ions from contaminated water, we have developed a novel bioremediation technology based on self-immobilization of the Caulobacter crescentus recombinant strain JS4022/p723-6H, which overexpresses hexahistidine peptide on the surface of the bacterial cells and serves as a whole-cell adsorbent for dissolved heavy metals. Biofilms formed by JS4022/p723-6H are effective at retaining cadmium from bacterial growth media or environmental water samples. Here we provide additional experiment data discussing the application potential of this new technology. Supplementation of calcium to the growth media produced robust JS4022/p723-6H cells by alleviating their sensitivity to chelators. After growth in the presence of 0.3% CaCl(2)·2H(2)O, double the amount of JS4022/p723-6H cells survived the treatment with 2 mM EDTA. Free cells of JS4022/p723-6H effectively sequestered 51% of the total cadmium from a Lake Erie water sample at pH 5.4, compared to 37% retrieved by the control strain. Similar levels of adsorption were observed at pH 4.2 as well. Cells of JS4022/p723-6H were tolerant of acid treatment for 90 min at pH ≥1.1 or 120 min at pH ≥2.5, which provides an avenue for the convenient regeneration of the bacterial cells metal-binding capacity with acidic solutions. Designs of possible bioreactors and an operation system are also presented.

  11. Chemometric assessment of enhanced bioremediation of oil contaminated soils

    DEFF Research Database (Denmark)

    Soleimani, Mohsen; Farhoudi, Majid; Christensen, Jan H.

    2013-01-01

    Bioremediation is a promising technique for reclamation of oil polluted soils. In this study, six methods for enhancing bioremediation were tested on oil contaminated soils from three refinery areas in Iran (Isfahan, Arak, and Tehran). The methods included bacterial enrichment, planting...... steranes were used for determining the level and type of hydrocarbon contamination. The same methods were used to study oil weathering of 2 to 6 ring polycyclic aromatic compounds (PACs). Results demonstrated that bacterial enrichment and addition of nutrients were most efficient with 50% to 62% removal...

  12. Arsenate resistant Penicillium coffeae: a potential fungus for soil bioremediation.

    Science.gov (United States)

    Bhargavi, S D; Savitha, J

    2014-03-01

    Bioremediation is an effective method for the treatment of major metal contaminated sites. Fungi were isolated from soil samples collected from different arsenate contaminated areas across India. An isolate, Penicillium coffeae, exhibited resistance to arsenate up to 500 mM. Results indicated that pretreatment of biomass with alkali (NaOH) enhanced the percentage of adsorption to 66.8% as compared to that of live and untreated dead biomass whose adsorption was 22.9% and 60.2% respectively. The physiological parameters evaluated in this study may help pilot studies aimed at bioremediation of arsenate contaminated effluents using arsenate resistant fungus P. coffeae.

  13. TECHNOLOGIES FOR BIOREMEDIATION OF SOILS CONTAMINATED WITH PETROLEUM PRODUCTS

    Directory of Open Access Journals (Sweden)

    Roxana Gabriela POPA

    2012-05-01

    Full Text Available Biological methods for remediation of soils is based on the degradation of pollutants due to activity of microorganisms (bacteria, fungi. Effectiveness of biological decontamination of soils depends on the following factors: biodegradation of pollutants, type of microorganisms used, choice of oxidant and nutrient and subject to clean up environmental characteristics. Ex situ techniques for bioremediation of soils polluted are: composting (static / mechanical agitation, land farming and biopiles. Techniques in situ bioremediation of soils polluted are: bioventingul, biospargingul and biostimulation – bioaugumentarea.

  14. Bioremediation of Industrial Waste Through Enzyme Producing Marine Microorganisms.

    Science.gov (United States)

    Sivaperumal, P; Kamala, K; Rajaram, R

    2017-01-01

    Bioremediation process using microorganisms is a kind of nature-friendly and cost-effective clean green technology. Recently, biodegradation of industrial wastes using enzymes from marine microorganisms has been reported worldwide. The prospectus research activity in remediation area would contribute toward the development of advanced bioprocess technology. To minimize industrial wastes, marine enzymes could constitute a novel alternative in terms of waste treatment. Nowadays, the evidence on the mechanisms of bioremediation-related enzymes from marine microorganisms has been extensively studied. This review also will provide information about enzymes from various marine microorganisms and their complexity in the biodegradation of comprehensive range of industrial wastes.

  15. Metals, minerals and microbes: geomicrobiology and bioremediation.

    Science.gov (United States)

    Gadd, Geoffrey Michael

    2010-03-01

    Microbes play key geoactive roles in the biosphere, particularly in the areas of element biotransformations and biogeochemical cycling, metal and mineral transformations, decomposition, bioweathering, and soil and sediment formation. All kinds of microbes, including prokaryotes and eukaryotes and their symbiotic associations with each other and 'higher organisms', can contribute actively to geological phenomena, and central to many such geomicrobial processes are transformations of metals and minerals. Microbes have a variety of properties that can effect changes in metal speciation, toxicity and mobility, as well as mineral formation or mineral dissolution or deterioration. Such mechanisms are important components of natural biogeochemical cycles for metals as well as associated elements in biomass, soil, rocks and minerals, e.g. sulfur and phosphorus, and metalloids, actinides and metal radionuclides. Apart from being important in natural biosphere processes, metal and mineral transformations can have beneficial or detrimental consequences in a human context. Bioremediation is the application of biological systems to the clean-up of organic and inorganic pollution, with bacteria and fungi being the most important organisms for reclamation, immobilization or detoxification of metallic and radionuclide pollutants. Some biominerals or metallic elements deposited by microbes have catalytic and other properties in nanoparticle, crystalline or colloidal forms, and these are relevant to the development of novel biomaterials for technological and antimicrobial purposes. On the negative side, metal and mineral transformations by microbes may result in spoilage and destruction of natural and synthetic materials, rock and mineral-based building materials (e.g. concrete), acid mine drainage and associated metal pollution, biocorrosion of metals, alloys and related substances, and adverse effects on radionuclide speciation, mobility and containment, all with immense social

  16. Developments in Bioremediation of Soils and Sediments Pollutedwith Metals and Radionuclides: 2. Field Research on Bioremediation of Metals and Radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Hazen, Terry C.; Tabak, Henry H.

    2007-03-15

    Bioremediation of metals and radionuclides has had manyfield tests, demonstrations, and full-scale implementations in recentyears. Field research in this area has occurred for many different metalsand radionuclides using a wide array of strategies. These strategies canbe generally characterized in six major categories: biotransformation,bioaccumulation/bisorption, biodegradation of chelators, volatilization,treatment trains, and natural attenuation. For all field applicationsthere are a number of critical biogeochemical issues that most beaddressed for the successful field application. Monitoring andcharacterization parameters that are enabling to bioremediation of metalsand radionuclides are presented here. For each of the strategies a casestudy is presented to demonstrate a field application that uses thisstrategy.

  17. Partial characterization of biosurfactant from Lactobacillus pentosus and comparison with sodium dodecyl sulphate for the bioremediation of hydrocarbon contaminated soil.

    Science.gov (United States)

    Moldes, A B; Paradelo, R; Vecino, X; Cruz, J M; Gudiña, E; Rodrigues, L; Teixeira, J A; Domínguez, J M; Barral, M T

    2013-01-01

    The capability of a cell bound biosurfactant produced by Lactobacillus pentosus, to accelerate the bioremediation of a hydrocarbon-contaminated soil, was compared with a synthetic anionic surfactant (sodium dodecyl sulphate SDS-). The biosurfactant produced by the bacteria was analyzed by Fourier transform infrared spectroscopy (FTIR) that clearly indicates the presence of OH and NH groups, C=O stretching of carbonyl groups and NH nebding (peptide linkage), as well as CH2-CH3 and C-O stretching, with similar FTIR spectra than other biosurfactants obtained from lactic acid bacteria. After the characterization of biosurfactant by FTIR, soil contaminated with 7,000 mg Kg(-1) of octane was treated with biosurfactant from L. pentosus or SDS. Treatment of soil for 15 days with the biosurfactant produced by L. pentosus led to a 65.1% reduction in the hydrocarbon concentration, whereas SDS reduced the octane concentration to 37.2% compared with a 2.2% reduction in the soil contaminated with octane in absence of biosurfactant used as control. Besides, after 30 days of incubation soil with SDS or biosurfactant gave percentages of bioremediation around 90% in both cases. Thus, it can be concluded that biosurfactant produced by L. pentosus accelerates the bioremediation of octane-contaminated soil by improving the solubilisation of octane in the water phase of soil, achieving even better results than those reached with SDS after 15-day treatment.

  18. Partial Characterization of Biosurfactant from Lactobacillus pentosus and Comparison with Sodium Dodecyl Sulphate for the Bioremediation of Hydrocarbon Contaminated Soil

    Directory of Open Access Journals (Sweden)

    A. B. Moldes

    2013-01-01

    Full Text Available The capability of a cell bound biosurfactant produced by Lactobacillus pentosus, to accelerate the bioremediation of a hydrocarbon-contaminated soil, was compared with a synthetic anionic surfactant (sodium dodecyl sulphate SDS-. The biosurfactant produced by the bacteria was analyzed by Fourier transform infrared spectroscopy (FTIR that clearly indicates the presence of OH and NH groups, C=O stretching of carbonyl groups and NH nebding (peptide linkage, as well as CH2–CH3 and C–O stretching, with similar FTIR spectra than other biosurfactants obtained from lactic acid bacteria. After the characterization of biosurfactant by FTIR, soil contaminated with 7,000 mg Kg−1 of octane was treated with biosurfactant from L. pentosus or SDS. Treatment of soil for 15 days with the biosurfactant produced by L. pentosus led to a 65.1% reduction in the hydrocarbon concentration, whereas SDS reduced the octane concentration to 37.2% compared with a 2.2% reduction in the soil contaminated with octane in absence of biosurfactant used as control. Besides, after 30 days of incubation soil with SDS or biosurfactant gave percentages of bioremediation around 90% in both cases. Thus, it can be concluded that biosurfactant produced by L. pentosus accelerates the bioremediation of octane-contaminated soil by improving the solubilisation of octane in the water phase of soil, achieving even better results than those reached with SDS after 15-day treatment.

  19. Pilot-scale bioremediation of a petroleum hydrocarbon-contaminated clayey soil from a sub-Arctic site

    Energy Technology Data Exchange (ETDEWEB)

    Akbari, Ali; Ghoshal, Subhasis, E-mail: subhasis.ghoshal@mcgill.ca

    2014-09-15

    Highlights: • Aeration and moisture addition alone caused extensive hydrocarbon biodegradation. • 30-day slurry reactor remediation endpoints attained in 385 days in biopiles. • High nitrogen concentrations inhibited hydrocarbon degradation. • Inhibition of biodegradation linked to lack of shifts in soil microbial community. - Abstract: Bioremediation is a potentially cost-effective solution for petroleum contamination in cold region sites. This study investigates the extent of biodegradation of petroleum hydrocarbons (C16–C34) in a pilot-scale biopile experiment conducted at 15 °C for periods up to 385 days, with a clayey soil, from a crude oil-impacted site in northern Canada. Although several studies on bioremediation of petroleum hydrocarbon-contaminated soils from cold region sites have been reported for coarse-textured, sandy soils, there are limited studies of bioremediation of petroleum contamination in fine-textured, clayey soils. Our results indicate that aeration and moisture addition was sufficient for achieving 47% biodegradation and an endpoint of 530 mg/kg for non-volatile (C16–C34) petroleum hydrocarbons. Nutrient amendment with 95 mg-N/kg showed no significant effect on biodegradation compared to a control system without nutrient but similar moisture content. In contrast, in a biopile amended with 1340 mg-N/kg, no statistically significant biodegradation of non-volatile fraction was detected. Terminal Restriction Fragment Length Polymorphism (T-RFLP) analyses of alkB and 16S rRNA genes revealed that inhibition of hydrocarbon biodegradation was associated with a lack of change in microbial community composition. Overall, our data suggests that biopiles are feasible for attaining the bioremediation endpoint in clayey soils. Despite the significantly lower biodegradation rate of 0.009 day{sup −1} in biopile tank compared to 0.11 day{sup −1} in slurry bioreactors for C16–C34 hydrocarbons, the biodegradation extents for this fraction

  20. Pilot-scale bioremediation of a petroleum hydrocarbon-contaminated clayey soil from a sub-Arctic site.

    Science.gov (United States)

    Akbari, Ali; Ghoshal, Subhasis

    2014-09-15

    Bioremediation is a potentially cost-effective solution for petroleum contamination in cold region sites. This study investigates the extent of biodegradation of petroleum hydrocarbons (C16-C34) in a pilot-scale biopile experiment conducted at 15°C for periods up to 385 days, with a clayey soil, from a crude oil-impacted site in northern Canada. Although several studies on bioremediation of petroleum hydrocarbon-contaminated soils from cold region sites have been reported for coarse-textured, sandy soils, there are limited studies of bioremediation of petroleum contamination in fine-textured, clayey soils. Our results indicate that aeration and moisture addition was sufficient for achieving 47% biodegradation and an endpoint of 530 mg/kg for non-volatile (C16-C34) petroleum hydrocarbons. Nutrient amendment with 95 mg-N/kg showed no significant effect on biodegradation compared to a control system without nutrient but similar moisture content. In contrast, in a biopile amended with 1340 mg-N/kg, no statistically significant biodegradation of non-volatile fraction was detected. Terminal Restriction Fragment Length Polymorphism (T-RFLP) analyses of alkB and 16S rRNA genes revealed that inhibition of hydrocarbon biodegradation was associated with a lack of change in microbial community composition. Overall, our data suggests that biopiles are feasible for attaining the bioremediation endpoint in clayey soils. Despite the significantly lower biodegradation rate of 0.009 day(-1) in biopile tank compared to 0.11 day(-1) in slurry bioreactors for C16-C34 hydrocarbons, the biodegradation extents for this fraction were comparable in these two systems.

  1. RNA-TGGE, a Tool for Assessing the Potential for Bioremediation in Impacted Marine Ecosystems

    Directory of Open Access Journals (Sweden)

    Krishna K. Kadali

    2015-08-01

    Full Text Available Cultivation-independent genomic approaches have greatly advanced our understanding of the ecology and diversity of microbial communities involved in biodegradation processes. However, much still needs to be resolved in terms of the structure, composition and dynamics of the microbial community in impacted ecosystems. Here we report on the RNA activity of the microbial community during the bioremediation process using RNA Temperature Gradient Gel Electrophoresis (RNA-TGGE. Dendrograms constructed from similarity matching data produced from the TGGE profiles separated a community exhibiting high remediation potential. Overall, increased Shannon Weaver Diversity indices (1–2.4 were observed in the high potential remediation treatment samples. The functionality of the microbial community was compared, with the microbial community showing the greatest organisation also showing the highest levels of hydrocarbon degradation. Subsequent sequencing of excised bands from the microbial community identified the presence of Gammaproteobacteria together with a number of uncultured bacteria. The data shows that RNA TGGE represents a simple, reproducible and effective tool for use in the assessment of a commercial bioremediation event, in terms of monitoring either the natural or augmented hydrocarbon-degrading microbial community.

  2. Bioremediation of oil refinery sludge by landfarming in semiarid conditions: influence on soil microbial activity.

    Science.gov (United States)

    Marin, J A; Hernandez, T; Garcia, C

    2005-06-01

    Bioremediation of a refinery sludge containing hydrocarbons in a semi-arid climate using landfarming techniques is described. The objective of this study was to assess the ability of this technique to reduce the total hydrocarbon content added to the soil with the refinery sludge in semiarid climate (low rain and high temperature). In addition, we have evaluated the effect of this technique on the microbial activity of the soil involved. For this, biological parameters (carbon fractions, microbial biomass carbon, basal respiration and ATP) and biochemical parameters(different enzymatic activities) were determined. The results showed that 80% of the hydrocarbons were eliminated in eleven months, half of this reduction taking place during the first three months. The labile carbon fractions, MBC, basal respiration and ATP of the soils submitted to landfarming showed higher values than the control soil during the first months of the process, although these values fell down by the end of the experimental period as the hydrocarbons were degraded by mineralisation. All the enzymatic activities studied: oxidoreductases such as dehydrogenase activity, and hydrolases of C(beta-glucosidase activity) and N Cycle (urease and protease) showed higher values in the soils amended with the refinery sludge than in the control. As in the case of the previous parameters, these value fell down as the bioremediation of the hydrocarbons progressed, many of them reaching levels similar to those of the control soil after eleven months.

  3. Performance Indicators for Uranium Bioremediation in the Subsurface: Basis and Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Long, Philip E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Yabusaki, Steven B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2006-12-29

    The purpose of this letter report is to identify performance indicators for in situ engineered bioremediation of subsurface uranium (U) contamination. This report focuses on in situ treatment of groundwater by biostimulation of extant in situ microbial populations (see http://128.3.7.51/NABIR/generalinfo/primers_guides/03_NABIR_primer.pdf for background information on bioremediation of metals and radionuclides). The treatment process involves amendment of the subsurface with an electron donor such as acetate, lactate, ethanol or other organic compound such that in situ microorganisms mediate the reduction of U(VI) to U(IV). U(VI) precipitates as uraninite or other insoluble U phase. Uranium is thus immobilized in place by such processes and is subject to reoxidation that may remobilize the reduced uranium. Related processes include augmenting the extant subsurface microbial populations, addition of electron acceptors, and introduction of chemically reducing materials such as zero-valent Fe. While metrics for such processes may be similar to those for in situ biostimulation, these related processes are not directly in the scope of this letter report.

  4. Ecogenomics of microbial communities in bioremediation of chlorinated contaminated sites

    Directory of Open Access Journals (Sweden)

    Farai eMaphosa

    2012-10-01

    Full Text Available Organohalide compounds such as chloroethenes, chloroethanes and polychlorinated benzenes are among the most significant pollutants in the world. These compounds are often found in contamination plumes with other pollutants such as solvents, pesticides and petroleum derivatives. Microbial bioremediation of contaminated sites, has become commonplace whereby key processes involved in bioremediation include anaerobic degradation and transformation of these organohalides by organohalide respiring bacteria and also via hydrolytic, oxygenic and reductive mechanisms by aerobic bacteria. Microbial ecogenomics has enabled us to not only study the microbiology involved in these complex processes but also develop tools to better monitor and assess these sites during bioremediation. Microbial ecogenomics have capitalized on recent advances in high-throughput and -output genomics technologies in combination with microbial physiology studies to address these complex bioremediation problems at a system level. Advances in environmental metagenomics, transcriptomics and proteomics have provided insights into key genes and their regulation in the environment. They have also given us clues into microbial community structures, dynamics and functions at contaminated sites. These techniques have not only aided us in understanding the lifestyles of common organohalide respirers, for example Dehalococcoides, Dehalobacter and Desulfitobacterium, but also provided insights into novel and yet uncultured microorganisms found in organohalide respiring consortia. In this paper we look at how ecogenomic studies have aided us to understand the microbial structures and functions in response to environmental stimuli such as the presence of chlorinated pollutants.

  5. ENGINEERING ISSUE: IN SITU BIOREMEDIATION OF CONTAMINATED UNSATURATED SUBSURFACE SOILS

    Science.gov (United States)

    An emerging technology for the remediation of unsaturated subsurface soils involves the use of microorganisms to degrade contaminants which are present in such soils. Understanding the processes which drive in situ bioremediation, as well as the effectiveness and efficiency of th...

  6. Bioremediation of lead contaminated soil with Rhodobacter sphaeroides.

    Science.gov (United States)

    Li, Xiaomin; Peng, Weihua; Jia, Yingying; Lu, Lin; Fan, Wenhong

    2016-08-01

    Bioremediation with microorganisms is a promising technique for heavy metal contaminated soil. Rhodobacter sphaeroides was previously isolated from oil field injection water and used for bioremediation of lead (Pb) contaminated soil in the present study. Based on the investigation of the optimum culturing conditions and the tolerance to Pb, we employed the microorganism for the remediation of Pb contaminated soil simulated at different contamination levels. It was found that the optimum temperature, pH, and inoculum size for R. sphaeroides is 30-35 °C, 7, and 2 × 10(8) mL(-1), respectively. Rhodobacter sphaeroides did not remove the Pb from soil but did change its speciation. During the bioremediation process, more available fractions were transformed to less accessible and inert fractions; in particular, the exchangeable phase was dramatically decreased while the residual phase was substantially increased. A wheat seedling growing experiment showed that Pb phytoavailability was reduced in amended soils. Results inferred that the main mechanism by which R. sphaeroides treats Pb contaminated soil is the precipitation formation of inert compounds, including lead sulfate and lead sulfide. Although the Pb bioremediation efficiency on wheat was not very high (14.78% root and 24.01% in leaf), R. sphaeroides remains a promising alternative for Pb remediation in contaminated soil.

  7. Electromigration of Contaminated Soil by Electro-Bioremediation Technique

    Science.gov (United States)

    Azhar, A. T. S.; Nabila, A. T. A.; Nurshuhaila, M. S.; Shaylinda, M. Z. N.; Azim, M. A. M.

    2016-07-01

    Soil contamination with heavy metals poses major environmental and human health problems. This problem needs an efficient method and affordable technological solution such as electro-bioremediation technique. The electro-bioremediation technique used in this study is the combination of bacteria and electrokinetic process. The aim of this study is to investigate the effectiveness of Pseudomonas putida bacteria as a biodegradation agent to remediate contaminated soil. 5 kg of kaolin soil was spiked with 5 g of zinc oxide. During this process, the anode reservoir was filled with Pseudomonas putida while the cathode was filled with distilled water for 5 days at 50 V of electrical gradient. The X-Ray Fluorescent (XRF) test indicated that there was a significant reduction of zinc concentration for the soil near the anode with 89% percentage removal. The bacteria count is high near the anode which is 1.3x107 cfu/gww whereas the bacteria count at the middle and near the cathode was 5.0x106 cfu/gww and 8.0x106 cfu/gww respectively. The migration of ions to the opposite charge of electrodes during the electrokinetic process resulted from the reduction of zinc. The results obtained proved that the electro-bioremediation reduced the level of contaminants in the soil sample. Thus, the electro-bioremediation technique has the potential to be used in the treatment of contaminated soil.

  8. BIOREMEDIATION OF HAZARDOUS WASTES - RESEARCH, DEVELOPMENT AND FIELD EVALUATIONS - 1995

    Science.gov (United States)

    The proceedings of the 1995 Symposium on Bioremediation of Hazardous Wastes, hosted by the Office of Research and Development (ORD) of the EPA in Rye Brook, New York. he symposium was the eighth annual meeting for the presentation of research conducted by EPA's Biosystems Technol...

  9. Use of Additives in Bioremediation of Contaminated Groundwater and Soil

    Science.gov (United States)

    This chapter reviews application of additives used in bioremediation of chlorinated solvents and fuels for groundwater and soil remediation. Soluble carbon substrates are applicable to most site conditions except aquifers with very high or very low groundwater flow. Slow-release ...

  10. In Situ Bioremediation of Energetic Compounds in Groundwater

    Science.gov (United States)

    2012-05-01

    complex mixture, such as cheese whey . The use of a single soluble substrate (1) simplifies the injection process , as the material can be metered into...42  Figure 16. Semi-passive bioremediation alternative with cheese whey for whole plume treatment...cheese whey for plume cutoff. ............. 46  Figure 18. Passive biobarrier alternative with EVO for plume cutoff

  11. Genomic and physiological perspectives on bioremediation processes at the FRC

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas, Erick; Leigh, Mary Beth; Hemme, Christopher; Gentry, Terry; Harzman, Christina; Wu, Weimin; Criddle, Craig S.; Zhou, Jizhong; Marsh, Terence; Tiedje, James M.

    2006-04-05

    A suite of molecular and physiological studies, including metal reduction assays, metagenomics, functional gene microarrays and community sequence analyses were applied to investigate organisms involved in bioremediation processes at the ERSP Field Research Center and to understand the effects of stress on the makeup and evolution of microbial communities to inform effective remediation strategies.

  12. OIL SPILL BIOREMEDIATION ON COASTAL SHORELINES: A CRITIQUE

    Science.gov (United States)

    The purpose of this chapter is not to provide an extensive review of the literature on oil spill bioremediation. For that, the reader is referred to Swannell et al. (1996), who have conducted the most exhaustive review I have yet to come across. Other reviews are also av...

  13. INTRINSIC BIOREMEDIATION OF A PETROLEUM-IMPACTED WETLAND

    Science.gov (United States)

    Following the 1994 San Jacinto River flood and oil spill in southeast Texas, a petroleum-contaminated wetland was reserved for a long-term research program to evaluate bioremediation as a viable spill response tool. The first phase of this program, presented in this paper, evalua...

  14. MICROBIAL POPULATION CHANGES DURING BIOREMEDIATION OF AN EXPERIMENTAL OIL SPILL

    Science.gov (United States)

    Three crude oil bioremediation techniques were applied in a randomized block field experiment simulating a coastal oil-spill. Four treatments (no oil control, oil alone, oil + nutrients, and oil + nutrients + an indigenous inoculum) were applied. In-situ microbial community str...

  15. Bioremediation of Petroleum Hydrocarbon-Contaminated Soils, Comprehensive Report

    Energy Technology Data Exchange (ETDEWEB)

    Altman, D.J.

    2001-01-12

    The US Department of Energy and the Institute for Ecology of Industrial Areas, Katowice, Poland have been cooperating in the development and implementation of innovative environmental remediation technologies since 1995. U.S. experts worked in tandem with counterparts from the IETU and CZOR throughout this project to characterize, assess and subsequently, design, implement and monitor a bioremediation system.

  16. [Effects and Biological Response on Bioremediation of Petroleum Contaminated Soil].

    Science.gov (United States)

    Yang, Qian; Wu, Man-li; Nie, Mai-qian; Wang, Ting-ting; Zhang, Ming-hui

    2015-05-01

    Bioaugmentation and biostimulation were used to remediate petroleum-contaminated soil which were collected from Zichang city in North of Shaanxi. The optimal bioremediation method was obtained by determining the total petroleum hydrocarbon(TPH) using the infrared spectroscopy. During the bioremediation, number of degrading strains, TPH catabolic genes, and soil microbial community diversity were determined by Most Probable Number (MPN), polymerase chain reaction (PCR) combined agarose electrophoresis, and PCR-denaturing gradient electrophoresis (DGGE). The results in different treatments showed different biodegradation effects towards total petroleum hydrocarbon (TPH). Biostimulation by adding N and P to soils achieved the best degradation effects towards TPH, and the bioaugmentation was achieved by inoculating strain SZ-1 to soils. Further analysis indicated the positive correlation between catabolic genes and TPH removal efficiency. During the bioremediation, the number of TPH and alkanes degrading strains was higher than the number of aromatic degrading strains. The results of PCR-DGGE showed microbial inoculums could enhance microbial community functional diversity. These results contribute to understand the ecologically microbial effects during the bioremediation of petroleum-polluted soil.

  17. Legal and social concerns to the development of bioremediation technologies

    Energy Technology Data Exchange (ETDEWEB)

    Bilyard, G.R.; McCabe, G.H.; White, K.A.; Gajewski, S.W.; Hendrickson, P.L.; Jaksch, J.A.; Kirwan-Taylor, H.A.; McKinney, M.D.

    1996-09-01

    The social and legal framework within which bioremediation technologies must be researched, developed, and deployed in the US are discussed in this report. Discussions focus on policies, laws and regulations, intellectual property, technology transfer, and stakeholder concerns. These discussions are intended to help program managers, scientists and engineers understand the social and legal framework within which they work, and be cognizant of relevant issues that must be navigated during bioremediation technology research, development, and deployment activities. While this report focuses on the legal and social environment within which the DOE operates, the laws, regulations and social processes could apply to DoD and other sites nationwide. This report identifies specific issues related to bioremediation technologies, including those involving the use of plants; native, naturally occurring microbes; non-native, naturally occurring microbes; genetically engineered organisms; and microbial products (e.g., enzymes, surfactants, chelating compounds). It considers issues that fall within the following general categories: US biotechnology policy and the regulation of field releases of organisms; US environmental laws and waste cleanup regulations; intellectual property and patenting issues; technology transfer procedures for commercializing technology developed through government-funded research; stakeholder concerns about bioremediation proposals; and methods for assuring public involvement in technology development and deployment.

  18. Optimal design of an in-situ bioremediation system using support vector machine and particle swarm optimization

    Science.gov (United States)

    ch, Sudheer; Kumar, Deepak; Prasad, Ram Kailash; Mathur, Shashi

    2013-08-01

    A methodology based on support vector machine and particle swarm optimization techniques (SVM-PSO) was used in this study to determine an optimal pumping rate and well location to achieve an optimal cost of an in-situ bioremediation system. In the first stage of the two stage methodology suggested for optimal in-situ bioremediation design, the optimal number of wells and their locations was determined from preselected candidate well locations. The pumping rate and well location in the first stage were subsequently optimized in the second stage of the methodology. The highly nonlinear system of equations governing in-situ bioremediation comprises the equations of flow and solute transport coupled with relevant biodegradation kinetics. A finite difference model was developed to simulate the process of in-situ bioremediation using an Alternate-Direction Implicit technique. This developed model (BIOFDM) yields the spatial and temporal distribution of contaminant concentration for predefined initial and boundary conditions. BIOFDM was later validated by comparing the simulated results with those obtained using BIOPLUME III for the case study of Shieh and Peralta (2005). The results were found to be in close agreement. Moreover, since the solution of the highly nonlinear equation otherwise requires significant computational effort, the computational burden in this study was managed within a practical time frame by replacing the BIOFDM model with a trained SVM model. Support Vector Machine which generates fast solutions in real time was considered to be a universal function approximator in the study. Apart from reducing the computational burden, this technique generates a set of near optimal solutions (instead of a single optimal solution) and creates a re-usable data base that could be used to address many other management problems. Besides this, the search for an optimal pumping pattern was directed by a simple PSO technique and a penalty parameter approach was adopted

  19. Optimal design of an in-situ bioremediation system using support vector machine and particle swarm optimization.

    Science.gov (United States)

    ch, Sudheer; Kumar, Deepak; Prasad, Ram Kailash; Mathur, Shashi

    2013-08-01

    A methodology based on support vector machine and particle swarm optimization techniques (SVM-PSO) was used in this study to determine an optimal pumping rate and well location to achieve an optimal cost of an in-situ bioremediation system. In the first stage of the two stage methodology suggested for optimal in-situ bioremediation design, the optimal number of wells and their locations was determined from preselected candidate well locations. The pumping rate and well location in the first stage were subsequently optimized in the second stage of the methodology. The highly nonlinear system of equations governing in-situ bioremediation comprises the equations of flow and solute transport coupled with relevant biodegradation kinetics. A finite difference model was developed to simulate the process of in-situ bioremediation using an Alternate-Direction Implicit technique. This developed model (BIOFDM) yields the spatial and temporal distribution of contaminant concentration for predefined initial and boundary conditions. BIOFDM was later validated by comparing the simulated results with those obtained using BIOPLUME III for the case study of Shieh and Peralta (2005). The results were found to be in close agreement. Moreover, since the solution of the highly nonlinear equation otherwise requires significant computational effort, the computational burden in this study was managed within a practical time frame by replacing the BIOFDM model with a trained SVM model. Support Vector Machine which generates fast solutions in real time was considered to be a universal function approximator in the study. Apart from reducing the computational burden, this technique generates a set of near optimal solutions (instead of a single optimal solution) and creates a re-usable data base that could be used to address many other management problems. Besides this, the search for an optimal pumping pattern was directed by a simple PSO technique and a penalty parameter approach was adopted

  20. In situ microcosms in aquifer bioremediation studies.

    Science.gov (United States)

    Mandelbaum, R T; Shati, M R; Ronen, D

    1997-07-01

    The extent to which aquifer microbiota can be studied under laboratory or simulated conditions is limited by our inability to authentically duplicate natural conditions in the laboratory. Therefore, extrapolation of laboratory results to real aquifer situations is often criticized, unless validation of the data is performed in situ. Reliable data acquisition is critical for the estimation of chemical and biological reaction rates of biodegradation processes in groundwater and as input data for mathematical models. Typically, in situ geobiochemical studies relied on the injection of groundwater spiked with compounds or bacteria of interest into the aquifer, followed by monitoring the changes over time and space. In situ microcosms provide a more confined study site for measurements of microbial reactions, yet closer to natural conditions than laboratory microcosms. Two basic types of in situ aquifer microcosm have been described in recent years, and both originated from in situ instruments initially designed for geochemical measurements. Gillham et al. [Ground Water 28 (1990) 858-862] constructed an instrument that isolates a portion of an aquifer for in situ biochemical rate measurements. More recently Shati et al. [Environ. Sci. Technol. 30 (1996) 2646-2653] modified a multilayer sampler for studying the activity of inoculated bacteria in a contaminated aquifer Keeping in mind recent advances in environmental microbiology methodologies such as immunofluorescence direct counts, oligonucleotide and PCR probes, fatty acid methyl esther analysis for the detection and characterization of bacterial communities, measurement of mRNA and expression of proteins, it is evident that much new information can now be gained from in situ work. Using in situ microcosms to study bioremediation efficiencies, the fate of introduced microorganisms and general geobiochemical aquifer processes can shed more realistic light on the microbial underworld. The aim of this paper is to

  1. Shape Similarity Measures of Linear Entities

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The essential of feature matching technology lies in how to measure the similarity of spatial entities.Among all the possible similarity measures,the shape similarity measure is one of the most important measures because it is easy to collect the necessary parameters and it is also well matched with the human intuition.In this paper a new shape similarity measure of linear entities based on the differences of direction change along each line is presented and its effectiveness is illustrated.

  2. Bioremediation potential of diesel-contaminated Libyan soil.

    Science.gov (United States)

    Koshlaf, Eman; Shahsavari, Esmaeil; Aburto-Medina, Arturo; Taha, Mohamed; Haleyur, Nagalakshmi; Makadia, Tanvi H; Morrison, Paul D; Ball, Andrew S

    2016-11-01

    Bioremediation is a broadly applied environmentally friendly and economical treatment for the clean-up of sites contaminated by petroleum hydrocarbons. However, the application of this technology to contaminated soil in Libya has not been fully exploited. In this study, the efficacy of different bioremediation processes (necrophytoremediation using pea straw, bioaugmentation and a combination of both treatments) together with natural attenuation were assessed in diesel contaminated Libyan soils. The addition of pea straw was found to be the best bioremediation treatment for cleaning up diesel contaminated Libyan soil after 12 weeks. The greatest TPH degradation, 96.1% (18,239.6mgkg(-1)) and 95% (17,991.14mgkg(-1)) were obtained when the soil was amended with pea straw alone and in combination with a hydrocarbonoclastic consortium respectively. In contrast, natural attenuation resulted in a significantly lower TPH reduction of 76% (14,444.5mgkg(-1)). The presence of pea straw also led to a significant increased recovery of hydrocarbon degraders; 5.7log CFU g(-1) dry soil, compared to 4.4log CFUg(-1) dry soil for the untreated (natural attenuation) soil. DGGE and Illumina 16S metagenomic analyses confirm shifts in bacterial communities compared with original soil after 12 weeks incubation. In addition, metagenomic analysis showed that original soil contained hydrocarbon degraders (e.g. Pseudoxanthomonas spp. and Alcanivorax spp.). However, they require a biostimulant (in this case pea straw) to become active. This study is the first to report successful oil bioremediation with pea straw in Libya. It demonstrates the effectiveness of pea straw in enhancing bioremediation of the diesel-contaminated Libyan soil.

  3. DEMONSTRATION BULLETIN: NEW YORK STATE MULTI-VENDOR BIOREMEDIATION - R.E. WRIGHT ENVIRONMENTAL, INC.'S IN-SITU BIOREMEDIATION TREATMENT SYSTEM

    Science.gov (United States)

    The R.E. Wright Environmental, Inc.‘s (REWEI) In-situ Bioremediation Treatment System is an in-situ bioremediation technology for the treatment of soils contaminated with organic compounds. According to the Developer, contaminated soils are remediated in-situ by stimulating the a...

  4. Mass Transfer Limited Enhanced Bioremediation at Dnapl Source Zones: a Numerical Study

    Science.gov (United States)

    Kokkinaki, A.; Sleep, B. E.

    2011-12-01

    dechlorination kinetics were reflected in a transient, spatially heterogeneous bioavailability number and dissolution enhancement. In agreement with the literature, source zone architecture largely determined the impact of mass transfer on potential dissolution enhancement, with bioavailability decreasing the most at high ganglia to pool ratios. The results of this study suggest that if mass transfer rate limitations are not considered in designing bioremediation applications at DNAPL source zones, the enhancement of DNAPL depletion and the overall effectiveness of enhanced bioremediation may be significantly overestimated.

  5. Similarity Structure of Wave-Collapse

    DEFF Research Database (Denmark)

    Rypdal, Kristoffer; Juul Rasmussen, Jens; Thomsen, Kenneth

    1985-01-01

    Similarity transformations of the cubic Schrödinger equation (CSE) are investigated. The transformations are used to remove the explicit time variation in the CSE and reduce it to differential equations in the spatial variables only. Two different methods for similarity reduction are employed and...

  6. Similarity transformations of MAPs

    Directory of Open Access Journals (Sweden)

    Andersen Allan T.

    1999-01-01

    Full Text Available We introduce the notion of similar Markovian Arrival Processes (MAPs and show that the event stationary point processes related to two similar MAPs are stochastically equivalent. This holds true for the time stationary point processes too. We show that several well known stochastical equivalences as e.g. that between the H 2 renewal process and the Interrupted Poisson Process (IPP can be expressed by the similarity transformations of MAPs. In the appendix the valid region of similarity transformations for two-state MAPs is characterized.

  7. Dynamics and role of sphingomonas/mycobacterium populations during bio-remediation of weathered PAH-contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Bastiaens, L.; Ryngaert, A.; Leys, N.; Van Houtven, D.; Gemoets, J. [Flemish Institute for Technological Research-Vito, Mol (Belgium); Goethals, L. [ENVISAN, Aalst, (Belgium); Springael, D. [Catholic University of Leuven-KUL, Leuven (Belgium)

    2005-07-01

    Polycyclic Aromatic Hydrocarbons (PAHs) are major soil pollutants in many industrialized countries. During the last decades, a diversity of PAH-degrading micro-organisms has been isolated, suggesting possibilities for bio-remediation. However, biodegradation of PAHs in contaminated soils is not always successful. The low bio-availability of the PAHs is the major problem, especially in weathered soils. In these soils a tightly sorbed PAH-fraction is present which is in general hardly accessible for microorganisms. In order to bio-remedy PAHs also in weathered soils, stimulation of bacteria which have special strategies to access sorbed organics may be a solution. Sphingomonas and Mycobacterium strains may represent such bacteria as (I) they are often isolated as PAH degraders, (II) they are ubiquitously present in PAH-contaminated soils, and (III) they display features which might promote bioavailability. Lab- and pilot-scale experiments were set up in order (A) to study the dynamics of indigenous Sphingomonas and Mycobacterium populations during bio-remediation, and (B) to evaluate their role in the biodegradation of the less bio-available PAH-fraction during treatment of an historic PAH polluted soil. The soil was treated under natural soil moisture conditions and slurry conditions. The experimental set-ups ranged from 2 g lab-scale test to pilot experiments in 1 ton bio-piles and dry solid reactors (50 kg 70% dry matter soil). Different additives were evaluated for stimulation of the Sphingomonas and Mycobacterium population as a strategy to improve bio-remediation of PAHs. The evolution of this microbial population was followed using culture-independent general and genus-specific PCR-based detection methods targeting the 16S rRNA genes of the eu-bacterial community, Mycobacterium or the Sphingomonas populations, respectively. During the different bio-remediation experiments that were conducted, the Mycobacterium population remained very stable, only minor

  8. In situ bioremediation: A network model of diffusion and flow in granular porous media

    Energy Technology Data Exchange (ETDEWEB)

    Griffiths, S.K.; Nilson, R.H.; Bradshaw, R.W.

    1997-04-01

    In situ bioremediation is a potentially expedient, permanent and cost- effective means of waste site decontamination. However, permeability reductions due to the transport and deposition of native fines or due to excessive microorganism populations may severely inhibit the injection of supplemental oxygen in the contamination zone. To help understand this phenomenon, we have developed a micro-mechanical network model of flow, diffusion and particle transport in granular porous materials. The model differs from most similar models in that the network is defined by particle positions in a numerically-generated particle array. The model is thus widely applicable to computing effective transport properties for both ordered and realistic random porous media. A laboratory-scale apparatus to measure permeability reductions has also been designed, built and tested.

  9. Rapid toluene mineralization by aquifer microorganisms at Adak, Alaska: Implications for intrinsic bioremediation in cold environments

    Science.gov (United States)

    Bradley, P.M.; Chapelle, F.H.

    1995-01-01

    Sediments from a relatively cold (5??C), petroleum hydrocarbon-contaminated aquifer in Adak, AK, mineralized [14C]toluene at an aerobic rate (16.3% day-1 at 5??C) comparable to that (5.1% day-1 at 20??C) of sediments from a more temperate aquifer at Hanahan, SC. In addition, rates of overall microbial metabolism in sediments from the two aquifers, as estimated by [1 -14C]acetate mineralization, were similar (???10.6% h-1) at their respective in situ temperatures. These results are not consistent with the common assumption that biodegradation rates in cold ground-water systems are depressed relative to more temperate systems. Furthermore, these results suggest that intrinsic bioremediation of petroleum hydrocarbon contaminants in cold groundwater systems may be technically feasible, in some cases.

  10. Bioremediation in marine ecosystems: a computational study combining ecological modelling and flux balance analysis

    OpenAIRE

    Marianna eTaffi; Nicola ePaoletti; Claudio eAngione; Sandra ePucciarelli; Mauro eMarini; Pietro eLio

    2014-01-01

    The pressure to search effective bioremediation methodologies for contaminated ecosystems has led to the large-scale identification of microbial species and metabolic degradation pathways. However, minor attention has been paid to the study of bioremediation in marine food webs and to the definition of integrated strategies for reducing bioaccumulation in species. We propose a novel computational framework for analysing the multiscale effects of bioremediation at the ecosystem level, based o...

  11. Bioremediation in marine ecosystems: a computational study combining ecological modeling and flux balance analysis

    OpenAIRE

    Taffi, Marianna; Paoletti, Nicola; Angione, Claudio; Pucciarelli, Sandra; Marini, Mauro; Liò, Pietro

    2014-01-01

    The pressure to search effective bioremediation methodologies for contaminated ecosystems has led to the large-scale identification of microbial species and metabolic degradation pathways. However, minor attention has been paid to the study of bioremediation in marine food webs and to the definition of integrated strategies for reducing bioaccumulation in species. We propose a novel computational framework for analysing the multiscale effects of bioremediation at the ecosystem level, based on...

  12. New Similarity Functions

    DEFF Research Database (Denmark)

    Yazdani, Hossein; Ortiz-Arroyo, Daniel; Kwasnicka, Halina

    2016-01-01

    In data science, there are important parameters that affect the accuracy of the algorithms used. Some of these parameters are: the type of data objects, the membership assignments, and distance or similarity functions. This paper discusses similarity functions as fundamental elements in membership...

  13. Clustering by Pattern Similarity

    Institute of Scientific and Technical Information of China (English)

    Hai-xun Wang; Jian Pei

    2008-01-01

    The task of clustering is to identify classes of similar objects among a set of objects. The definition of similarity varies from one clustering model to another. However, in most of these models the concept of similarity is often based on such metrics as Manhattan distance, Euclidean distance or other Lp distances. In other words, similar objects must have close values in at least a set of dimensions. In this paper, we explore a more general type of similarity. Under the pCluster model we proposed, two objects are similar if they exhibit a coherent pattern on a subset of dimensions. The new similarity concept models a wide range of applications. For instance, in DNA microarray analysis, the expression levels of two genes may rise and fall synchronously in response to a set of environmental stimuli. Although the magnitude of their expression levels may not be close, the patterns they exhibit can be very much alike. Discovery of such clusters of genes is essential in revealing significant connections in gene regulatory networks. E-commerce applications, such as collaborative filtering, can also benefit from the new model, because it is able to capture not only the closeness of values of certain leading indicators but also the closeness of (purchasing, browsing, etc.) patterns exhibited by the customers. In addition to the novel similarity model, this paper also introduces an effective and efficient algorithm to detect such clusters, and we perform tests on several real and synthetic data sets to show its performance.

  14. Judgments of brand similarity

    NARCIS (Netherlands)

    Bijmolt, THA; Wedel, M; Pieters, RGM; DeSarbo, WS

    1998-01-01

    This paper provides empirical insight into the way consumers make pairwise similarity judgments between brands, and how familiarity with the brands, serial position of the pair in a sequence, and the presentation format affect these judgments. Within the similarity judgment process both the formatio

  15. New Similarity Functions

    DEFF Research Database (Denmark)

    Yazdani, Hossein; Ortiz-Arroyo, Daniel; Kwasnicka, Halina

    2016-01-01

    In data science, there are important parameters that affect the accuracy of the algorithms used. Some of these parameters are: the type of data objects, the membership assignments, and distance or similarity functions. This paper discusses similarity functions as fundamental elements in membership...... assignments. The paper introduces Weighted Feature Distance (WFD), and Prioritized Weighted Feature Distance (PWFD), two new distance functions that take into account the diversity in feature spaces. WFD functions perform better in supervised and unsupervised methods by comparing data objects on their feature...... spaces, in addition to their similarity in the vector space. Prioritized Weighted Feature Distance (PWFD) works similarly as WFD, but provides the ability to give priorities to desirable features. The accuracy of the proposed functions are compared with other similarity functions on several data sets...

  16. Microbial changes in rhizospheric soils contaminated with petroleum hydrocarbons after bioremediation

    Institute of Scientific and Technical Information of China (English)

    LIN Xin; LI Pei-jun; ZHOU Qi-xing; XU Hua-xia; ZHANG Hai-rong

    2004-01-01

    Effects of bioremediation on microbial communities in soils contaminated with petroleum hydrocarbons are a scientific problem to be solved. Changes in dominate microbial species and the total amount of microorganisms including bacteria and fungi in rhizospheric soils after bioremediation were thus evaluated using field bioremediation experiments. The results showed that there were changed dominant microorganisms including 11 bacterial strains which are mostly Gram positive bacteria and 6 fungal species which were identified. The total amount of microorganisms including bacteria and fungi increased after bioremediation of microbial agents combined with planting maize. On the contrary, fungi in rhizospheric soils were inhibited by adding microbial agents combined with planting soybean.

  17. Subtask 1.16-Slow-Release Bioremediation Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Marc D. Kurz; Edwin S. Olson

    2006-07-31

    Low-cost methods are needed to enhance various bioremediation technologies, from natural attenuation to heavily engineered remediation of subsurface hydrocarbon contamination. Many subsurface sites have insufficient quantities of nitrogen and phosphorus, resulting in poor bioactivity and increased remediation time and costs. The addition of conventional fertilizers can improve bioactivity, but often the nutrients dissolve quickly and migrate away from the contaminant zone before being utilized by the microbes. Through this project, conducted by the Energy & Environmental Research Center, polymers were developed that slowly release nitrogen and phosphorus into the subsurface. Conceptually, these polymers are designed to adhere to soil particles in the subsurface contamination zone where they slowly degrade and release nutrients over longer periods of time compared to conventional fertilizer applications. Tests conducted during this study indicate that some of the developed polymers have excellent potential to satisfy the microbial requirements for enhanced bioremediation.

  18. Fungal degradation of pesticides - construction of microbial consortia for bioremediation

    DEFF Research Database (Denmark)

    Ellegaard-Jensen, Lea

    in groundwater contamination. New technologies are therefore needed for cleaning up contaminated soil and water resources. This PhD was part of the project entitled Microbial Remediation of Contaminated Soil and Water Resources (MIRESOWA) where the overall aim is to develop new technologies for bioremediation...... of pesticide contaminated soil and water. The objectives of this PhD were to investigate fungal degradation of pesticides and following to construct microbial consortia for bioremediation. In Manuscript I the fungal degradation of the phenylurea herbicide diuron was studied. Isolates of soil fungi of the genus...... be a result of co-operative catabolism or physical interactions between the organisms improving growth and/or distribution of fungi and bacteria. The bacterial strains applied were Sphingomonas sp. SRS2, Variovorax sp. SRS16 and Arthrobacter globiformis D47 and the fungal strains were Mortierella sp. LEJ702...

  19. Structural analysis of enzymes used for bioindustry and bioremediation.

    Science.gov (United States)

    Tanokura, Masaru; Miyakawa, Takuya; Guan, Lijun; Hou, Feng

    2015-01-01

    Microbial enzymes have been widely applied in the large-scale, bioindustrial manufacture of food products and pharmaceuticals due to their high substrate specificity and stereoselectivity, and their effectiveness under mild conditions with low environmental burden. At the same time, bioremedial techniques using microbial enzymes have been developed to solve the problem of industrial waste, particularly with respect to persistent chemicals and toxic substances. And finally, structural studies of these enzymes have revealed the mechanistic basis of enzymatic reactions, including the stereoselectivity and binding specificity of substrates and cofactors. The obtained structural insights are useful not only to deepen our understanding of enzymes with potential bioindustrial and/or bioremedial application, but also for the functional improvement of enzymes through rational protein engineering. This review shows the structural bases for various types of enzymatic reactions, including the substrate specificity accompanying cofactor-controlled and kinetic mechanisms.

  20. [Bioremediation of heavy metal pollution by edible fungi: a review].

    Science.gov (United States)

    Liu, Jian-Fei; Hu, Liu-Jie; Liao, Dun-Xiu; Su, Shi-Ming; Zhou, Zheng-Ke; Zhang, Sheng

    2011-02-01

    Bioremediation is the method of using organisms and their derivatives to absorb heavy metals from polluted environment, with the characteristics of low cost, broad sources, and no secondary pollution. Heavy metals enrichment by edible fungi is an important research focus of bioremediation, because it can decrease the eco-toxicity of heavy metals via the uptake by edible fungi, and thereby, take a definite role in heavy metal remediation. This paper reviewed the research progress on the enrichment of heavy metal copper, cadmium, lead, zinc, arsenic, and chromium by edible fungi and the possible enrichment mechanisms, and prospected the development and applications of heavy metal enrichment by edible fungi in the management of polluted environment.

  1. Contributions of biosurfactants to natural or induced bioremediation.

    Science.gov (United States)

    Lawniczak, Lukasz; Marecik, Roman; Chrzanowski, Lukasz

    2013-03-01

    The number of studies dedicated to evaluating the influence of biosurfactants on bioremediation efficiency is constantly growing. Although significant progress regarding the explanation of mechanisms behind biosurfactant-induced effects could be observed, there are still many factors which are not sufficiently elucidated. This corresponds to the fact that although positive influence of biosurfactants is often reported, there are also numerous cases where no or negative effect was observed. This review summarizes the recent finding in the field of biosurfactant-amended bioremediation, focusing mainly on a critical approach towards potential limitations and causes of failure while investigating the effects of biosurfactants on the efficiency of biodegradation and phytoextraction processes. It also provides a summary of successive steps, which should be taken into consideration when designing biosurfactant-related treatment processes.

  2. Engineered Intrinsic Bioremediation of Ammonium Perchlorate in Groundwater

    Science.gov (United States)

    2010-12-01

    drive an aquifer anaerobic by biostimulation. Project tasks are to: 1) isolate and characterize novel perchlorate-reducing bacteria in addition to...bioremediation with the GA application is to engineer natural subsurface microbial communities ( aquifer biofilms) to give them the ability to degrade (reduce...hydrogen as electron donor for chloroform cometabolism by a mixed, methanogenic culture. Environ. Sci. Technol. 31: 880–885 Weuster-Botz, D. and Wandrey

  3. Assisted bioremediation tests on three natural soils contaminated with benzene

    Directory of Open Access Journals (Sweden)

    Maria Manuela Carvalho

    2015-07-01

    Full Text Available Bioremediation is an attractive and useful method of remediation of soils contaminated with petroleum hydrocarbons because it is simple to maintain, applicable in large areas, is economic and enables an effective destruction of the contaminant. Usually, the autochthone microorganisms have no ability to degrade these compounds, and otherwise, the contaminated sites have inappropriate environmental conditions for microorganism’s development. These problems can be overcome by assisted bioremediation (bioaugmentation and/or biostimulation. In this study the assisted bioremediation capacity on the rehabilitation of three natural sub-soils (granite, limestone and schist contaminated with benzene was evaluated. Two different types of assisted bioremediation were used: without and with ventilation (bioventing. The bioaugmentation was held by inoculating the soil with a consortium of microorganisms collected from the protection area of crude oil storage tanks in a refinery. In unventilated trials, biostimulation was accomplished by the addition of a nutrient mineral media, while in bioventing oxygen was also added. The tests were carried out at controlled temperature of 25 ºC in stainless steel columns where the moist soil contaminated with benzene (200 mg per kg of soil occupied about 40% of the column’s volume. The processes were daily monitored in discontinued mode. Benzene concentration in the gas phase was quantified by gas chromatography (GC-FID, oxygen and carbon dioxide concentrations were monitored by respirometry. The results revealed that the three contaminated soils were remediated using both technologies, nevertheless, the bioventing showed faster rates. With this work it was proved that respirometric analysis is an appropriate instrument for monitoring the biological activity.

  4. Biodegradation Rates Assessment For An In Situ Bioremediation Process

    Science.gov (United States)

    Troquet, J.; Poutier, F.

    Bioremediation methods seem a promising way of dealing with soil and subsoil con- tamination by organic substances. The biodegradation process is supported by micro- organisms which use the organic carbon from the pollutants as energy source and cells building blocks. However, bioremediation is not yet universally understood and its success is still an intensively debated issue because all soils and groundwater are not able to sustain biological growth and, then, cannot be successfully bioremediated. The outcome of each degradation process depends on several factors, which, such as oxygen transfer and pollutant bio-availability, can be controlled and are therefore key variables of such bioremediation processes. Then, it is essential to carry out a fea- sibility study based on pilot-testing before starting a remediation project in order to determine the best formulation of nutrients and bacteria to use for the specific condi- tions encountered. The scope of this work is to study the main parameters of the process and its physi- cal limiting steps in order to determine the biodegradation rates in a specific case of contamination. Several ground samples from an actual petroleum hydrocarbon con- taminated site have been laboratory tested. Five fixed bed column reactors, enabling the study of the influence of the different op- erating variables on the biodegradation kinetics, are used. The stoichiometric equation for bacteria growth and pollutant degradation has been established, allowing the de- termination of mass balances. Biodegradation monitoring is achieved by continuously measuring the emissions of carbon dioxide production and intermittently by analysing residual hydrocarbons. Results lead to the knowledge of biodegradation rates which allow to determine the treatment duration and cost.

  5. Environmental bioindication, biomonitoring, and bioremediation of organometal(loid)s.

    Science.gov (United States)

    Thayer, John S

    2010-01-01

    Environmentally occurring organometal(loid)s have generated some severe health and safety problems. Consequently, scientists have been investigating various organisms to show the presence of such compounds (bioindicators), to follow their movement through the environment (biomonitors), and to remove them (bioremediators). Examples of such organisms and the mechanisms of their action(s) are discussed. Also mentioned are those organisms that form organometal(loid)s as a way of removing toxic inorganic species.

  6. Environmental Factors and Bioremediation of Xenobiotics Using White Rot Fungi

    OpenAIRE

    Magan, Naresh; Fragoeiro, Silvia; Bastos, Catarina

    2010-01-01

    This review provides background information on the importance of bioremediation approaches. It describes the roles of fungi, specifically white rot fungi, and their extracellular enzymes, laccases, ligninases, and peroxidises, in the degradation of xenobiotic compounds such as single and mixtures of pesticides. We discuss the importance of abiotic factors such as water potential, temperature, and pH stress when considering an environmental screening approach, and examples are provided of the ...

  7. USING PHYTOREMEDIATION AND BIOREMEDIATION FOR PROTECTION SOIL NEAR GRAVEYARD

    OpenAIRE

    Katarzyna Ignatowicz

    2016-01-01

    The aim of present research was to assess the usefulness of Basket willow (Salix viminalis) to phytoremediation and bioremediation of sorption subsoil contaminated with pesticides. Studies upon purification of sorption material consisting of a soil and composting sewage sludge were conducted under pot experiment conditions. The study design included control pot along with 3 other ones polluted with pesticides. The vegetation season has lasted since spring till late autumn 2015. After acclimat...

  8. Bioremediation of severely weathered hydrocarbons: is it possible?

    Energy Technology Data Exchange (ETDEWEB)

    Gallego, J. R.; Villa, R.; Sierra, C.; Sotres, A.; Pelaez, A. I.; Sanchez, J.

    2009-07-01

    Weathering processes of spilled hydrocarbons promote a reduced biodegradability of petroleum compounds mixtures, and consequently bioremediation techniques are often ruled out within the selection of suitable remediation approaches. This is truly relevant wherever old spills at abandoned industrial sites have to be remediated. However it is well known most of the remaining fractions and individual compounds of weathered oil are still biodegradable, although at slow rates than alkanes or no and two-ring aromatics. (Author)

  9. Selection of electron acceptors and strategies for in situ bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Norris, R.D. [Eckenfelder, Inc., Nashville, TN (United States)

    1995-12-31

    The most critical aspect of designing in situ bioremediation systems is, typically, the selection and method of delivery of the electron acceptor. Nitrate, sulfate, and several forms of oxygen can be introduced, depending on the contaminants and the site conditions. Oxygen can be added as air, pure oxygen, hydrogen peroxide, or an oxygen release compound. Simplistic cost calculations can illustrate the advantages of some methods over others, providing technical requirements can be met.

  10. Heavy Metal Polluted Soils: Effect on Plants and Bioremediation Methods

    OpenAIRE

    Chibuike, G. U.; Obiora, S. C.

    2014-01-01

    Soils polluted with heavy metals have become common across the globe due to increase in geologic and anthropogenic activities. Plants growing on these soils show a reduction in growth, performance, and yield. Bioremediation is an effective method of treating heavy metal polluted soils. It is a widely accepted method that is mostly carried out in situ; hence it is suitable for the establishment/reestablishment of crops on treated soils. Microorganisms and plants employ different mechanisms for...

  11. Bioremediation of Southern Mediterranean oil polluted sites comes of age.

    Science.gov (United States)

    Daffonchio, Daniele; Ferrer, Manuel; Mapelli, Francesca; Cherif, Ameur; Lafraya, Alvaro; Malkawi, Hanan I; Yakimov, Michail M; Abdel-Fattah, Yasser R; Blaghen, Mohamed; Golyshin, Peter N; Kalogerakis, Nicolas; Boon, Nico; Magagnini, Mirko; Fava, Fabio

    2013-09-25

    Mediterranean Sea is facing a very high risk of oil pollution due to the high number of oil extractive and refining sites along the basin coasts, and the intense maritime traffic of oil tankers. All the Mediterranean countries have adopted severe regulations for minimizing pollution events and bioremediation feasibility studies for the most urgent polluted sites are undergoing. However, the analysis of the scientific studies applying modern 'meta-omics' technologies that have been performed on marine oil pollution worldwide showed that the Southern Mediterranean side has been neglected by the international research. Most of the studies in the Mediterranean Sea have been done in polluted sites of the Northern side of the basin. Those of the Southern side are poorly studied, despite many of the Southern countries being major oil producers and exporters. The recently EU-funded research project ULIXES has as a major objective to increase the knowledge of the bioremediation potential of sites from the Southern Mediterranean countries. ULIXES is targeting four major polluted sites on the coastlines of Egypt, Jordan, Morocco and Tunisia, including seashore sands, lagoons, and oil refinery polluted sediments. The research is designed to unravel, categorize, catalogue, exploit and manage the diversity and ecology of microorganisms thriving in these polluted sites. Isolation of novel hydrocarbon degrading microbes and a series of state of the art 'meta-omics' technologies are the baseline tools for improving our knowledge on biodegradation capacities mediated by microbes under different environmental settings and for designing novel site-tailored bioremediation approaches. A network of twelve European and Southern Mediterranean partners is cooperating for plugging the existing gap of knowledge for the development of novel bioremediation processes targeting such poorly investigated polluted sites.

  12. Similar component analysis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong; WANG Xin; LI Junwei; CAO Xianguang

    2006-01-01

    A new unsupervised feature extraction method called similar component analysis (SCA) is proposed in this paper. SCA method has a self-aggregation property that the data objects will move towards each other to form clusters through SCA theoretically,which can reveal the inherent pattern of similarity hidden in the dataset. The inputs of SCA are just the pairwise similarities of the dataset,which makes it easier for time series analysis due to the variable length of the time series. Our experimental results on many problems have verified the effectiveness of SCA on some engineering application.

  13. Challenging oil bioremediation at deep-sea hydrostatic pressure

    Directory of Open Access Journals (Sweden)

    Alberto Scoma

    2016-08-01

    Full Text Available The Deepwater Horizon (DWH accident has brought oil contamination of deep-sea environments to worldwide attention. The risk for new deep-sea spills is not expected to decrease in the future, as political pressure mounts to access deep-water fossil reserves, and poorly tested technologies are used to access oil. This also applies to the response to oil-contamination events, with bioremediation the only (biotechnology presently available to combat deep-sea spills. Many questions about the fate of petroleum-hydrocarbons at deep-sea remain unanswered, as much as the main constraints limiting bioremediation under increased hydrostatic pressures and low temperatures. The microbial pathways fueling oil take up are unclear, and the mild upregulation observed for beta-oxidation-related genes in both water and sediments contrasts with the high amount of alkanes present in the spilled-oil. The fate of solid alkanes (tar and that of hydrocarbons degradation rates was largely overlooked, as the reason why the most predominant hydrocarbonoclastic genera were not enriched at deep-sea, despite being present at hydrocarbon seeps at the Gulf of Mexico. This mini-review aims at highlighting the missing information in the field, proposing a holistic approach where in situ and ex situ studies are integrated to reveal the principal mechanisms accounting for deep-sea oil bioremediation.

  14. Biodegradation and bioremediation of hydrocarbons in extreme environments.

    Science.gov (United States)

    Margesin, R; Schinner, F

    2001-09-01

    Many hydrocarbon-contaminated environments are characterized by low or elevated temperatures, acidic or alkaline pH, high salt concentrations, or high pressure, Hydrocarbon-degrading microorganisms, adapted to grow and thrive in these environments, play an important role in the biological treatment of polluted extreme habitats. The biodegradation (transformation or mineralization) of a wide range of hydrocarbons, including aliphatic, aromatic, halogenated and nitrated compounds, has been shown to occur in various extreme habitats. The biodegradation of many components of petroleum hydrocarbons has been reported in a variety of terrestrial and marine cold ecosystems. Cold-adapted hydrocarbon degraders are also useful for wastewater treatment. The use of thermophiles for biodegradation of hydrocarbons with low water solubility is of interest, as solubility and thus bioavailability, are enhanced at elevated temperatures. Thermophiles, predominantly bacilli, possess a substantial potential for the degradation of environmental pollutants, including all major classes. Indigenous thermophilic hydrocarbon degraders are of special significance for the bioremediation of oil-polluted desert soil. Some studies have investigated composting as a bioremediation process. Hydrocarbon biodegradation in the presence of high salt concentrations is of interest for the bioremediation of oil-polluted salt marshes and industrial wastewaters, contaminated with aromatic hydrocarbons or with chlorinated hydrocarbons. Our knowledge of the biodegradation potential of acidophilic, alkaliphilic, or barophilic microorganisms is limited.

  15. Characterization of weathered petroleum hydrocarbons during a landfarming bioremediation study

    Directory of Open Access Journals (Sweden)

    Maletić Snežana

    2012-01-01

    Full Text Available Landfarming bioremediation was performed over 2 years on soil heavily polluted with weathered oil and oil derivatives: 23200 mg kg-1 of mineral oil, 35300 mg kg-1 total hydrocarbons, and 8.65 mg kg-1 of total PAHs. During the experiment, mineral oil, total hydrocarbon and PAH concentrations decreased by approximately 53%, 27% and 72%, respectively. A GC/MS-Scan was used to identify the crude oil components that persist after bioremediation treatment of contaminated soil and the metabolites generated during this process. The data shows that in weathered-hydrocarbons contaminated soil, the number of initially detected compounds after the bioremediation process further decreased over a 2 year period, and at the same time several new compounds were observed at the end of experiment. Higher persistence was also shown for heavier n-alkanes and branched alkanes, which could be detected over a longer period of time. The analysis highlights the importance of n-alkanes, their substituted derivatives and polycyclic aromatic hydrocarbons as the most significant pollutants.

  16. Monitoring bioremediation of atrazine in soil microcosms using molecular tools.

    Science.gov (United States)

    Sagarkar, Sneha; Mukherjee, Shinjini; Nousiainen, Aura; Björklöf, Katarina; Purohit, Hemant J; Jørgensen, Kirsten S; Kapley, Atya

    2013-01-01

    Molecular tools in microbial community analysis give access to information on catabolic potential and diversity of microbes. Applied in bioremediation, they could provide a new dimension to improve pollution control. This concept has been demonstrated in the study using atrazine as model pollutant. Bioremediation of the herbicide, atrazine, was analyzed in microcosm studies by bioaugmentation, biostimulation and natural attenuation. Genes from the atrazine degrading pathway atzA/B/C/D/E/F, trzN, and trzD were monitored during the course of treatment and results demonstrated variation in atzC, trzD and trzN genes with time. Change in copy number of trzN gene under different treatment processes was demonstrated by real-time PCR. The amplified trzN gene was cloned and sequence data showed homology to genes reported in Arthrobacter and Nocardioides. Results demonstrate that specific target genes can be monitored, quantified and correlated to degradation analysis which would help in predicting the outcome of any bioremediation strategy.

  17. Bioremediation of Oil Spills in Cold Environments: A Review

    Institute of Scientific and Technical Information of China (English)

    YANG Si-Zhong; JIN Hui-Jun; WEI Zhi; HE Rui-Xia; JI Yan-Jun; LI Xiu-Mei; YU Shao-Peng

    2009-01-01

    Oil spills have become a serious problem in cold environments with the ever-increasing resource exploitation,transportation,storage,and accidental leakage of oil.Several techniques,including physical,chemical,and biological methods,are used to recover spilled oil from the environment.Bioremediation is a promising option for remediation since it is effective and economic in removing oil with less undue environmental damages.However,it is a relatively slow process in cold regions and the degree of success depends on a number of factors,including the properties and fate of oil spilled in cold environments,and the major microbial and environmental limitations of bioremediation.The microbial factors include bioavailability of hydrocarbons,mass transfer through the cell membrane,and metabolic limitations.As for the environmental limitations in the cold regions,the emphasis is on soil temperatures,freeze-thaw processes,oxygen and nutrients availability,toxicity,and electron acceptors.There have been several cases of success in the polar regions,particularly in the Arctic and sub-Arctic regions.However,the challenges and constraints for bioremediation in cold environments remain large.

  18. Microbial inoculants and fertilization for bioremediation of oil in wetlands

    Energy Technology Data Exchange (ETDEWEB)

    Neralla, S.; Wright, A.L.; Weaver, R.W. [Texas A and M Univ., College Station, TX (United States). Dept. of Soil and Crop Sciences

    1995-12-31

    Bioremediation is an attractive alternative to physical methods of oil spill cleanup in wetlands where the ecosystem can be easily damaged. Because populations of oil-degrading microorganisms are usually low in wetlands, there is potential for increasing bioremediation through bioaugmentation in conjunction with N and P supplementation. Eight microbial inoculant products were added to microcosms containing soil from a salt marsh. Four of these products were also used in mesocosms containing Spartina alterniflora grown in a glasshouse. In unfertilized microcosms, the extent of oil degraded as measured by carbon dioxide evolution during 90 days, was 30% higher in the product with the highest activity than was recorded in the control with oil by 36%. None of the products when added to the fertilized soil increased activity above that of the fertilized control with oil. Addition of oil to microcosms increased populations of hydrocarbon-degrading microorganisms, but bioaugmentation products did not increase populations. Neither addition of products nor fertilization enhanced the disappearance of oil in mesocosms in the glasshouse. Approximately 50% of the weathered oil disappeared in 41 d for all treatments. Because bioaugmentation did not enhance oil degradation, it seems that natural populations of hydrocarbon-degrading microorganisms were adequate in the salt marsh soil for bioremediation.

  19. Bioremediation for coal-fired power stations using macroalgae.

    Science.gov (United States)

    Roberts, David A; Paul, Nicholas A; Bird, Michael I; de Nys, Rocky

    2015-04-15

    Macroalgae are a productive resource that can be cultured in metal-contaminated waste water for bioremediation but there have been no demonstrations of this biotechnology integrated with industry. Coal-fired power production is a water-limited industry that requires novel approaches to waste water treatment and recycling. In this study, a freshwater macroalga (genus Oedogonium) was cultivated in contaminated ash water amended with flue gas (containing 20% CO₂) at an Australian coal-fired power station. The continuous process of macroalgal growth and intracellular metal sequestration reduced the concentrations of all metals in the treated ash water. Predictive modelling shows that the power station could feasibly achieve zero discharge of most regulated metals (Al, As, Cd, Cr, Cu, Ni, and Zn) in waste water by using the ash water dam for bioremediation with algal cultivation ponds rather than storage of ash water. Slow pyrolysis of the cultivated algae immobilised the accumulated metals in a recalcitrant C-rich biochar. While the algal biochar had higher total metal concentrations than the algae feedstock, the biochar had very low concentrations of leachable metals and therefore has potential for use as an ameliorant for low-fertility soils. This study demonstrates a bioremediation technology at a large scale for a water-limited industry that could be implemented at new or existing power stations, or during the decommissioning of older power stations.

  20. Challenging Oil Bioremediation at Deep-Sea Hydrostatic Pressure

    Science.gov (United States)

    Scoma, Alberto; Yakimov, Michail M.; Boon, Nico

    2016-01-01

    The Deepwater Horizon accident has brought oil contamination of deep-sea environments to worldwide attention. The risk for new deep-sea spills is not expected to decrease in the future, as political pressure mounts to access deep-water fossil reserves, and poorly tested technologies are used to access oil. This also applies to the response to oil-contamination events, with bioremediation the only (bio)technology presently available to combat deep-sea spills. Many questions about the fate of petroleum-hydrocarbons within deep-sea environments remain unanswered, as well as the main constraints limiting bioremediation under increased hydrostatic pressures and low temperatures. The microbial pathways fueling oil bioassimilation are unclear, and the mild upregulation observed for beta-oxidation-related genes in both water and sediments contrasts with the high amount of alkanes present in the spilled oil. The fate of solid alkanes (tar), hydrocarbon degradation rates and the reason why the most predominant hydrocarbonoclastic genera were not enriched at deep-sea despite being present at hydrocarbon seeps at the Gulf of Mexico have been largely overlooked. This mini-review aims at highlighting the missing information in the field, proposing a holistic approach where in situ and ex situ studies are integrated to reveal the principal mechanisms accounting for deep-sea oil bioremediation. PMID:27536290

  1. A case study of the intrinsic bioremediation of petroleum hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Barker, G.W.; Raterman, K.T.; Fisher, J.B.; Corgan, J.M. [and others

    1995-12-31

    Condensate liquids have been found to contaminate soil and groundwater at two gas production sites in the Denver Basin operated by Amoco Production Co. These sites have been closely monitored since July 1993 to determine whether intrinsic aerobic or anaerobic bioremediation of hydrocarbons occurs at a sufficient rate and to an adequate endpoint to support a no-intervention decision. Groundwater monitoring and analysis of soil cores suggest that intrinsic bioremediation is occurring at these sites by multiple pathways including aerobic oxidation, Fe{sup 3+} reduction, and sulfate reduction. In laboratory experiments the addition of gas condensate hydrocarbons to saturated soil from the gas production site stimulated sulfate reduction under anaerobic and oxygen-limiting conditions, and nitrate and Fe{sup 3+} reduction under oxygen-limiting conditions, compared to biotic controls that lacked hydrocarbon and sterile controls. The sulfate reduction corresponded to a reduction in the amount of toluene relative to other hydrocarbons. These results confirmed that subsurface soils at the gas production site have the potential for intrinsic bioremediation of hydrocarbons.

  2. Cold climate bioremediation : a comparison of various approaches

    Energy Technology Data Exchange (ETDEWEB)

    Reimer, K.J.; Colden, M.; Francis, P.; Mauchan, J. [Royal Military Coll. of Canada, Kingston, ON (Canada); Mohn, W.W. [British Columbia Univ., Vancouver, BC (Canada); Poland, J.S. [Queen' s Univ., Kingston, ON (Canada)

    2003-07-01

    Bioremediation is a method commonly used to treat hydrocarbon contaminated soils in temperate climates. However, the method has received much less attention in cold and remote regions of Canada because of the low temperatures and lack of supporting infrastructure. Bioremediation methods based on biopiles and landfarms can be specifically adapted to cold and remote regions, and may offer a cost-effective solution to remediating areas that have frequent and significant fuel spills. Studies at many sites north of latitudes 65 degrees N have indicated the presence of cold-adapted psychrophilic organisms that can degrade hydrocarbons, particularly if aerated or augmented with fertilizers, native organisms, or bulking agents. The significance of natural attenuation in cold climates was examined. It was shown that temperature is the most critical limiting factor at such sites. The effectiveness of heated aeration systems in prolonging the biodegradation treatment was demonstrated at the CFS Alert site on the northern tip of Ellesmere Island. Simple aeration/insulation systems were used to decontaminate biopiles of soil at optimum temperatures for psychrophiles over a 12 month period. The ambient temperature during the treatment period was -45 degrees C. It was demonstrated that bioremediation is possible in the Arctic, particularly when assisted by nutrients. The treatment season can be extended by heating the biopiles. It was also noted that volatilization can account for a major portion of the hydrocarbon loss. 38 refs., 1 tab., 5 figs.

  3. Social evolution of toxic metal bioremediation in Pseudomonas aeruginosa.

    Science.gov (United States)

    O'Brien, Siobhán; Hodgson, David J; Buckling, Angus

    2014-07-22

    Bacteria are often iron-limited, and hence produce extracellular iron-scavenging siderophores. A crucial feature of siderophore production is that it can be an altruistic behaviour (individually costly but benefitting neighbouring cells), thus siderophore producers can be invaded by non-producing social 'cheats'. Recent studies have shown that siderophores can also bind other heavy metals (such as Cu and Zn), but in this case siderophore chelation actually reduces metal uptake by bacteria. These complexes reduce heavy metal toxicity, hence siderophore production may contribute to toxic metal bioremediation. Here, we show that siderophore production in the context of bioremediation is also an altruistic trait and can be exploited by cheating phenotypes in the opportunistic pathogen Pseudomonas aeruginosa. Specifically, we show that in toxic copper concentrations (i) siderophore non-producers evolve de novo and reach high frequencies, and (ii) producing strains are fitter than isogenic non-producing strains in monoculture, and vice versa in co-culture. Moreover, we show that the evolutionary effect copper has on reducing siderophore production is greater than the reduction observed under iron-limited conditions. We discuss the relevance of these results to the evolution of siderophore production in natural communities and heavy metal bioremediation.

  4. Bioremediation potential of five strains of Pseudomonas sp.

    Directory of Open Access Journals (Sweden)

    Stamenov Dragana R.

    2015-01-01

    Full Text Available Because of their huge biodiversity and metabolic capabilities, the application of microorganisms as bioremediation agents is a way to enhance pollutant degradation. The aim of this research was to investigate the potential of five strains of Pseudomonas sp. as possible bioremediation agents. Strains are from the Collection of the Microbiology Department, Faculty of Agriculture, Novi Sad. Bacterial strains were cultivated in King’s B liquid medium and incubated in shak­er at 28°C. Starter culture was obtained after 24h, CFU 108. This 24h old bacterial culture was used for the analysis of influence of five different natural naphthenic acids. Bacterial growth was determined spectrophotometrically through optical density, after 24h and 48h of growth. Our results showed that two bacterial strains (PS V1 and PS2 had better growth after 48h as they used C from the petroleum derivates. The growth of these strains was increased by 72% and 25% with deri­vates concentration of 10-5 mol/cm3 and 10-6 mol/cm3, respectively. The results of this research showed the potential of certain bacterial strains as bioremediators. [Projekat Ministarstva nauke Republike Srbije, br. TD 31027 i br. III 043002

  5. Biodegradation and bioremediation of hydrocarbons in extreme environments

    Energy Technology Data Exchange (ETDEWEB)

    Margesin, R.; Schinner, F. [Innsbruck Univ. (Austria). Inst. fuer Mikrobiologie

    2001-07-01

    Many hydrocarbon-contaminated environments are characterized by low or elevated temperatures, acidic or alkaline pH, high salt concentrations, or high pressure. Hydrocarbon-degrading microorganisms, adapted to grow and thrive in these environments, play an important role in the biological treatment of polluted extreme habitats. The biodegradation (transformation or mineralization) of a wide range of hydrocarbons, including aliphatic, aromatic, halogenated and nitrated compounds, has been shown to occur in various extreme habitats. The biodegradation of many components of petroleum hydrocarbons has been reported in a variety of terrestrial and marine cold ecosystems. Cold-adapted hydrocarbon degraders are also useful for wastewater treatment. The use of thermophiles for biodegradation of hydrocarbons with low water solubility is of interest, as solubility and thus bioavailability, are enhanced at elevated temperatures. Thermophiles, predominantly bacilli, possess a substantial potential for the degradation of environmental pollutants, including all major classes. Indigenous thermophilic hydrocarbon degraders are of special significance for the bioremediation of oil-polluted desert soil. Some studies have investigated composting as a bioremediation process. Hydrocarbon biodegradation in the presence of high salt concentrations is of interest for the bioremediation of oil-polluted salt marshes and industrial wastewaters, contaminated with aromatic hydrocarbons or with chlorinated hydrocarbons. Our knowledge of the biodegradation potential of acidophilic, alkaliphilic, or barophilic microorganisms is limited. (orig.)

  6. Gender similarities and differences.

    Science.gov (United States)

    Hyde, Janet Shibley

    2014-01-01

    Whether men and women are fundamentally different or similar has been debated for more than a century. This review summarizes major theories designed to explain gender differences: evolutionary theories, cognitive social learning theory, sociocultural theory, and expectancy-value theory. The gender similarities hypothesis raises the possibility of theorizing gender similarities. Statistical methods for the analysis of gender differences and similarities are reviewed, including effect sizes, meta-analysis, taxometric analysis, and equivalence testing. Then, relying mainly on evidence from meta-analyses, gender differences are reviewed in cognitive performance (e.g., math performance), personality and social behaviors (e.g., temperament, emotions, aggression, and leadership), and psychological well-being. The evidence on gender differences in variance is summarized. The final sections explore applications of intersectionality and directions for future research.

  7. Phylogenetic diversity of dominant bacterial communities during bioremediation of crude oil-polluted soil

    Directory of Open Access Journals (Sweden)

    Eugene Thomas Cloete

    2011-08-01

    degradation. Cluster analysis of DGGE bands using simple matching group average setting revealed that poultry droppings-amended soils and calcium ammonium nitrate-amended soils formed distinct clades meaning that the treatment selected similar bacterial populations for each of the treatments whereas NPK soils showed less association. Excision, reamplification and sequencing of dominant DGGE bands in biostimulated soils revealed the presence of distinct hydrocarbon degraders like Corynebacterium spp., Dietzia spp., low G+C Gram positive bacteria and some uncultured bacterial clones. Phylogenetic analysis of the 16S rRNA gene sequences of these dominant bacterial communities was conducted using the neighbour joining method of PHYLIP. Two distinct clades appeared in the tree clustered members of the Actinobacteria and Firmicutes separately. The overall data suggested that Gram positive bacteria especially members of the Actinobacteria may have a key role in bioremediation of crude oil-polluted soil.

  8. Bioremediation of hydrocarbon polluted soil - Improvement of in situ bioremediation by bioaugmentation with endogenous and exogenous strains

    OpenAIRE

    Tarayre, Cédric

    2010-01-01

    Petroleum pollution has now become a real problem because hydrocarbons are persistent contaminants in soils and water. Contamination problems increase when ages of relevant facilities, such as oil storage tanks and pipelines, increase over time. The evolution of Legislation concerning soil pollution has led to the need of efficient techniques able to restore the polluted ground. Unfortunately, these techniques are expensive. Bioremediation of hydrocarbon polluted soils has been recognized as...

  9. Geophysical monitoring of hydrological and biogeochemical transformations associated with Cr(VI) bioremediation.

    Science.gov (United States)

    Hubbard, Susan S; Williams, Ken; Conrad, Mark E; Faybishenko, Boris; Peterson, John; Chen, Jinsong; Long, Phil; Hazent, Terry

    2008-05-15

    Understanding how hydrological and biogeochemical properties change over space and time in response to remedial treatments is hindered by our ability to monitor these processes with sufficient resolution and over field relevant scales. Here, we explored the use of geophysical approaches for monitoring the spatiotemporal distribution of hydrological and biogeochemical transformations associated with a Cr(VI) bioremediation experiment performed at Hanford, WA. We first integrated hydrological wellbore and geophysical tomographic data sets to estimate hydrological zonation at the study site. Using results from laboratory biogeophysical experiments and constraints provided by field geochemical data sets, we then interpreted time-lapse seismic and radar tomographic data sets, collected during thirteen acquisition campaigns over a three year experimental period, in terms of hydrological and biogeochemical transformations. The geophysical monitoring data sets were used to infer: the spatial distribution of injected electron donor; the evolution of gas bubbles; variations in total dissolved solids (nitrate and sulfate) as a function of pumping activity; the formation of precipitates and dissolution of calcites; and concomitant changes in porosity. Although qualitative in nature, the integrated interpretation illustrates how geophysical techniques have the potential to provide a wealth of information about coupled hydrobiogeochemical responses to remedial treatments in high spatial resolution and in a minimally invasive manner. Particularly novel aspects of our study include the use of multiple lines of evidence to constrain the interpretation of a long-term, field-scale geophysical monitoring data set and the interpretation of the transformations as a function of hydrological heterogeneity and pumping activity.

  10. Compression-based Similarity

    CERN Document Server

    Vitanyi, Paul M B

    2011-01-01

    First we consider pair-wise distances for literal objects consisting of finite binary files. These files are taken to contain all of their meaning, like genomes or books. The distances are based on compression of the objects concerned, normalized, and can be viewed as similarity distances. Second, we consider pair-wise distances between names of objects, like "red" or "christianity." In this case the distances are based on searches of the Internet. Such a search can be performed by any search engine that returns aggregate page counts. We can extract a code length from the numbers returned, use the same formula as before, and derive a similarity or relative semantics between names for objects. The theory is based on Kolmogorov complexity. We test both similarities extensively experimentally.

  11. Segmentation Similarity and Agreement

    CERN Document Server

    Fournier, Chris

    2012-01-01

    We propose a new segmentation evaluation metric, called segmentation similarity (S), that quantifies the similarity between two segmentations as the proportion of boundaries that are not transformed when comparing them using edit distance, essentially using edit distance as a penalty function and scaling penalties by segmentation size. We propose several adapted inter-annotator agreement coefficients which use S that are suitable for segmentation. We show that S is configurable enough to suit a wide variety of segmentation evaluations, and is an improvement upon the state of the art. We also propose using inter-annotator agreement coefficients to evaluate automatic segmenters in terms of human performance.

  12. Biochar-carrying hydrocarbon decomposers promote degradation during the early stage of bioremediation

    Science.gov (United States)

    Galitskaya, Polina; Akhmetzyanova, Leisan; Selivanovskaya, Svetlana

    2016-10-01

    Oil pollution is one of the most serious current environmental problems. In this study, four strategies of bioremediation of oil-polluted soil were tested in the laboratory over a period of 84 days: (A) aeration and moistening; (B) amendment with 1 % biochar (w ⁄ w) in combination with A; amendment with 1 % biochar with immobilized Pseudomonas aeruginosa (C) or Acinetobacter radioresistens (D) in combination with A. All strategies used resulted in a decrease of the hydrocarbon content, while biochar addition (B, C, D strategies) led to acceleration of decomposition in the beginning. Microbial biomass and respiration rate increased significantly at the start of bioremediation. It was demonstrated that moistening and aeration were the main factors influencing microbial biomass, while implementation of biochar and introduction of microbes were the main factors influencing microbial respiration. All four remediation strategies altered bacterial community structure and phytotoxicity. The Illumina MiSeq method revealed 391 unique operational taxonomic units (OTUs) belonging to 40 bacterial phyla and a domination of Proteobacteria in all investigated soil samples. The lowest alpha diversity was observed in the samples with introduced bacteria on the first day of remediation. Metric multidimensional scaling demonstrated that in the beginning and at the end, microbial community structures were more similar than those on the 28th day of remediation. Strategies A and B decreased phytotoxicity of remediated soil between 2.5 and 3.1 times as compared with untreated soil. C and D strategies led to additional decrease of phytotoxicity between 2.1 and 3.2 times.

  13. Bioremediation techniques-classification based on site of application: principles, advantages, limitations and prospects.

    Science.gov (United States)

    Azubuike, Christopher Chibueze; Chikere, Chioma Blaise; Okpokwasili, Gideon Chijioke

    2016-11-01

    Environmental pollution has been on the rise in the past few decades owing to increased human activities on energy reservoirs, unsafe agricultural practices and rapid industrialization. Amongst the pollutants that are of environmental and public health concerns due to their toxicities are: heavy metals, nuclear wastes, pesticides, green house gases, and hydrocarbons. Remediation of polluted sites using microbial process (bioremediation) has proven effective and reliable due to its eco-friendly features. Bioremediation can either be carried out ex situ or in situ, depending on several factors, which include but not limited to cost, site characteristics, type and concentration of pollutants. Generally, ex situ techniques apparently are more expensive compared to in situ techniques as a result of additional cost attributable to excavation. However, cost of on-site installation of equipment, and inability to effectively visualize and control the subsurface of polluted sites are of major concerns when carrying out in situ bioremediation. Therefore, choosing appropriate bioremediation technique, which will effectively reduce pollutant concentrations to an innocuous state, is crucial for a successful bioremediation project. Furthermore, the two major approaches to enhance bioremediation are biostimulation and bioaugmentation provided that environmental factors, which determine the success of bioremediation, are maintained at optimal range. This review provides more insight into the two major bioremediation techniques, their principles, advantages, limitations and prospects.

  14. Bioremediation of polluted wasewaterwater influent: phiosphorus and nitrogen removal. Scientific Research and Essays

    DEFF Research Database (Denmark)

    Muchie, Mammo; Akpor, OB

    2010-01-01

    Akpor OB and Muchie M. (2010). Bioremediation of polluted wasewaterwater influent: phiosphorus and nitrogen removal. Scientific Research and Essays, Vol. 5(21), pp. 3222–3230......Akpor OB and Muchie M. (2010). Bioremediation of polluted wasewaterwater influent: phiosphorus and nitrogen removal. Scientific Research and Essays, Vol. 5(21), pp. 3222–3230...

  15. Modeling Application of Hydrogen Release Compound to Effect In Situ Bioremediation of Chlorinated Solvent - Contaminated Groundwater

    Science.gov (United States)

    2005-03-01

    substrate of choice to aid in the enhancing of bioremediation has varied from corn syrup, cheese whey , and molasses, to HRC®. One example of the use of...Bioremediation on the Fast Track. Water and Wastewater Products, July/August, 2003. Vogel, T. M., Criddle, C. S., McCarty, P. L

  16. BIOREMEDIATION OF AN EXPERIMENTAL OIL SPILL ON THE SHORELINE OF DELAWARE BAY

    Science.gov (United States)

    In the summer of 1994, a field study was undertaken in Delaware in which light crude oil was intentionally released onto plots to evaluate bioremediation. The objectives were to obtain credible statistical evidence to determine if bioremediation with inorganic mineral nutrients ...

  17. Variably saturated flow and multicomponent biogeochemical reactive transport modeling of a uranium bioremediation field experiment.

    Science.gov (United States)

    Yabusaki, Steven B; Fang, Yilin; Williams, Kenneth H; Murray, Christopher J; Ward, Andy L; Dayvault, Richard D; Waichler, Scott R; Newcomer, Darrell R; Spane, Frank A; Long, Philip E

    2011-11-01

    Three-dimensional, coupled variably saturated flow and biogeochemical reactive transport modeling of a 2008 in situ uranium bioremediation field experiment is used to better understand the interplay of transport and biogeochemical reactions controlling uranium behavior under pulsed acetate amendment, seasonal water table variation, spatially variable physical (hydraulic conductivity, porosity) and geochemical (reactive surface area) material properties. While the simulation of the 2008 Big Rusty acetate biostimulation field experiment in Rifle, Colorado was generally consistent with behaviors identified in previous field experiments at the Rifle IFRC site, the additional process and property detail provided several new insights. A principal conclusion from this work is that uranium bioreduction is most effective when acetate, in excess of the sulfate-reducing bacteria demand, is available to the metal-reducing bacteria. The inclusion of an initially small population of slow growing sulfate-reducing bacteria identified in proteomic analyses led to an additional source of Fe(II) from the dissolution of Fe(III) minerals promoted by biogenic sulfide. The falling water table during the experiment significantly reduced the saturated thickness of the aquifer and resulted in reactants and products, as well as unmitigated uranium, in the newly unsaturated vadose zone. High permeability sandy gravel structures resulted in locally high flow rates in the vicinity of injection wells that increased acetate dilution. In downgradient locations, these structures created preferential flow paths for acetate delivery that enhanced local zones of TEAP reactivity and subsidiary reactions. Conversely, smaller transport rates associated with the lower permeability lithofacies (e.g., fine) and vadose zone were shown to limit acetate access and reaction. Once accessed by acetate, however, these same zones limited subsequent acetate dilution and provided longer residence times that resulted

  18. Bioremediation of PAHs and VOCs: Advances in clay mineral-microbial interaction.

    Science.gov (United States)

    Biswas, Bhabananda; Sarkar, Binoy; Rusmin, Ruhaida; Naidu, Ravi

    2015-12-01

    Bioremediation is an effective strategy for cleaning up organic contaminants, such as polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs). Advanced bioremediation implies that biotic agents are more efficient in degrading the contaminants completely. Bioremediation by microbial degradation is often employed and to make this process efficient, natural and cost-effective materials can serve as supportive matrices. Clay/modified clay minerals are effective adsorbents of PAHs/VOCs, and readily available substrate and habitat for microorganisms in the natural soil and sediment. However, the mechanism underpinning clay-mediated biodegradation of organic compounds is often unclear, and this requires critical investigation. This review describes the role of clay/modified clay minerals in hydrocarbon bioremediation through interaction with microbial agents in specific scenarios. The vision is on a faster, more efficient and cost-effective bioremediation technique using clay-based products. This review also proposes future research directions in the field of clay modulated microbial degradation of hydrocarbons.

  19. Spatial planning

    OpenAIRE

    Dimitrov, Nikola; Koteski, Cane

    2016-01-01

    The professional book ,, Space planning "processed chapters on: space, concept and definition of space, space as a system, spatial economics, economic essence of space, space planning, social determinants of spatial planning, spatial planning as a process, factors development and elements in spatial planning, methodology, components and content of spatial planning stages and types of preparation of spatial planning, spatial planning and industrialization, industrialization, urbanization and s...

  20. [Bioremediation of petroleum hydrocarbon contaminated soil by bioaugmentation products].

    Science.gov (United States)

    Huang, Ting-Lin; Xu, Jin-Lan; Tang, Zhi-Xin; Xiao, Zhou-Qiang

    2009-06-15

    In an experimental investigation of bioaugmentation products affected on the petroleum contaminated soil. The influence of the bioaugmentation products dose, injections and temperature on bioremediation were studied. The results showed that the degradation rate was related positively to the amount of inoculation, when the dose was increased to 0.6 mg x kg(-1), total petroleum hydrocarbon (TPH) degradation rate was 87% in 48 days. The results of GC-MS indicated that the dominant petroleum constituents in oil-contaminated raw soil were 82.1% n-alkane, 16% alkene and little of others hydrocarbons, such as carotane, alkylnaphthalenes, hopanes, and steranes. The peaks amount of GC profile decreased from 32 to 14 after 40 days of bioremediation, this result indicated that branched alkanes, alkene, and alkylnaphthalenes were thoroughly degraded, then line alkanes, hopanes, and steranes were left in soil. In addition, the longer part of n-alkane were degraded with rate relatively higher, while the residual fraction at the end of the test is shorter part of n-alkane because bacteria degraded the longer n-alkane to shorter. The shorter n-alkane concentration decreased with increasing inoculation. One time injection of bioaugmentation products into soil clearly improved the biodegradation efficiency higher than injection of bioaugmentation products in turn. Soil temperature also affected TPH degradation rate when it was 30 degrees C, TPH rate reached 80%, where as when it was 20 degrees C, the TPH rate was lower to 60%, which indicated higher temperature improved TPH degradation and accelerated bioremediation.

  1. More Similar Than Different

    DEFF Research Database (Denmark)

    Pedersen, Mogens Jin

    2015-01-01

    What role do employee features play into the success of different personnel management practices for serving high performance? Using data from a randomized survey experiment among 5,982 individuals of all ages, this article examines how gender conditions the compliance effects of different...... incentive treatments—each relating to the basic content of distinct types of personnel management practices. The findings show that males and females are more similar than different in terms of the incentive treatments’ effects: Significant average effects are found for three out of five incentive...

  2. Mechanisms for similarity matching in disparity measurement

    Directory of Open Access Journals (Sweden)

    Ross eGoutcher

    2014-01-01

    Full Text Available Early neural mechanisms for the measurement of binocular disparity appear to operate in a manner consistent with cross-correlation-like processes. Consequently, cross-correlation, or cross-correlation-like procedures have been used in a range of models of disparity measurement. Using such procedures as the basis for disparity measurement creates a preference for correspondence solutions that maximise the similarity between local left and right eye image regions. Here, we examine how observers’ perception of depth in an ambiguous stereogram is affected by manipulations of luminance and orientation-based image similarity. Results show a strong effect of coarse-scale luminance similarity manipulations, but a relatively weak effect of finer-scale manipulations of orientation similarity. This is in contrast to the measurements of depth obtained from a standard cross-correlation model. This model shows strong effects of orientation similarity manipulations and weaker effects of luminance similarity. In order to account for these discrepancies, the standard cross-correlation approach may be modified to include an initial spatial frequency filtering stage. The performance of this adjusted model most closely matches human psychophysical data when spatial frequency filtering favours coarser scales. This is consistent with the operation of disparity measurement processes where spatial frequency and disparity tuning are correlated, or where disparity measurement operates in a coarse-to-fine manner.

  3. Similar dissection of sets

    CERN Document Server

    Akiyama, Shigeki; Okazaki, Ryotaro; Steiner, Wolfgang; Thuswaldner, Jörg

    2010-01-01

    In 1994, Martin Gardner stated a set of questions concerning the dissection of a square or an equilateral triangle in three similar parts. Meanwhile, Gardner's questions have been generalized and some of them are already solved. In the present paper, we solve more of his questions and treat them in a much more general context. Let $D\\subset \\mathbb{R}^d$ be a given set and let $f_1,...,f_k$ be injective continuous mappings. Does there exist a set $X$ such that $D = X \\cup f_1(X) \\cup ... \\cup f_k(X)$ is satisfied with a non-overlapping union? We prove that such a set $X$ exists for certain choices of $D$ and $\\{f_1,...,f_k\\}$. The solutions $X$ often turn out to be attractors of iterated function systems with condensation in the sense of Barnsley. Coming back to Gardner's setting, we use our theory to prove that an equilateral triangle can be dissected in three similar copies whose areas have ratio $1:1:a$ for $a \\ge (3+\\sqrt{5})/2$.

  4. Self-similar parabolic plasmonic beams.

    Science.gov (United States)

    Davoyan, Arthur R; Turitsyn, Sergei K; Kivshar, Yuri S

    2013-02-15

    We demonstrate that an interplay between diffraction and defocusing nonlinearity can support stable self-similar plasmonic waves with a parabolic profile. Simplicity of a parabolic shape combined with the corresponding parabolic spatial phase distribution creates opportunities for controllable manipulation of plasmons through a combined action of diffraction and nonlinearity.

  5. Similarity transformed semiclassical dynamics

    Science.gov (United States)

    Van Voorhis, Troy; Heller, Eric J.

    2003-12-01

    In this article, we employ a recently discovered criterion for selecting important contributions to the semiclassical coherent state propagator [T. Van Voorhis and E. J. Heller, Phys. Rev. A 66, 050501 (2002)] to study the dynamics of many dimensional problems. We show that the dynamics are governed by a similarity transformed version of the standard classical Hamiltonian. In this light, our selection criterion amounts to using trajectories generated with the untransformed Hamiltonian as approximate initial conditions for the transformed boundary value problem. We apply the new selection scheme to some multidimensional Henon-Heiles problems and compare our results to those obtained with the more sophisticated Herman-Kluk approach. We find that the present technique gives near-quantitative agreement with the the standard results, but that the amount of computational effort is less than Herman-Kluk requires even when sophisticated integral smoothing techniques are employed in the latter.

  6. Bioremediation of trinitrotolulene by a ruminal microorganism

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Taejin; Williamson, K.J.; Craig, A.M. [Oregon State Univ., Corvallis, OR (United States)

    1995-10-01

    2,4,6-trinitrotoluene (TNT) has been widely used for the production of explosives because of its low boiling point, high stability, low impact sensitivity, and safe manufacture. More than 1,100 military facilities, each potentially contaminated with munitions waste, are expected to require treatment of more than one million cubic yards of contaminated soils. The cost associated with remediation of these sites has been estimated to be in excess of $1.5 billion. Recently, researchers have studied ruminal microorganisms in relation to their ability to degrade xenobiotic compounds. Many of these organisms are strict anaerobes with optimal redox potentials as low as -420 mV. Ruminal organisms have been shown capable of destroying some pesticides, such as parathion, p-nitrophenol, and biphenyl-type compounds; thiono isomers, and nitrogen-containing heterocyclic plant toxins such as the pyrrolizidine alkaloids. Many of these compounds have structures similar to TNT. A TNT-degrading ruminal microorganism has been isolated from goat rumen fluid with successive enrichments on triaminotoluene (TAT) and TNT. The isolate, designated G.8, utilizes nitrate and lactate as the primary energy source. G.8 was able to tolerate and metabolite levels of TNT up to the saturation point of 125 mg/l.

  7. Hydrogen as an Indicator to Assess Biological Activity During Trace-Metal Bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Peter R. Jaffe, John Komlos, Derick Brown

    2005-09-27

    ) compared to soluble Fe(III) (ferric citrate). The addition of AQDS did not affect the rate of iron reduction for soluble Fe(III) but did increase the rate of surface bound Fe(III) reduction to values similar to soluble Fe(III). IOCS column experiments will be performed using acetate concentration ranges above and below the half saturation constant calculated from the batch experiments to verify if steady-state H2 concentrations vary with change in carbon concentration as predicted from the dual-donor modeling in phase 1. These results will determine if, and at what concentration, a carbon source added as an electron donor during a biostimulation scenario will compete with H2 as a co-electron donor and how this interaction will influence the use of H2 as an indicator of TEAP during bioremediation in an aquifer. The results for this phase of research are in Section 3.

  8. Microbial Bioremediation of Fuel Oil Hydrocarbons in Marine Environment

    Directory of Open Access Journals (Sweden)

    Sapna Pavitran

    2006-04-01

    Full Text Available Pollution in marine environment due to heavier petroleum products such as high-speeddiesel is known to take from days to months for complete natural remediation owing to its lowvolatility. For the survival of marine flora and fauna, it is important to control pollution causedby such recalcitrant and xenobiotic substances. Several petroleum hydrocarbons found in natureare toxic and recalcitrant. Therefore, pollution due to high-speed diesel is a cause of concern.The natural dispersion of high-speed diesel, a slow process, is attributed to an overall combinedeffect of physico-chemical and biological processes which take months for complete dispersion.History of marine oil spill bioremediation indicates limited laboratory studies. But experiencesfrom various oil spill management and field trials indicate important role of bioremediation, where,biodegradation of hydrocarbons through microbial mediators plays a major role in pollutant oildispersion. These microbial mediators such as bioemulsifiers and fimbrae, help in emulsification,dispersion, allowing attachment of bacteria to oil layers, followed by substrate-specific enzymaticbiodegradation in water.

  9. Bioremediation of Pyrene-Contaminated Soils Using Biosurfactant

    Directory of Open Access Journals (Sweden)

    Jorfi

    2014-10-01

    Full Text Available Background Polycyclic aromatic hydrocarbons (PAHs are persistence organic chemicals with proved carcinogenic and mutagenic hazards. These compounds are usually adsorbed in soils in vicinity of oil and gas industries. Bioremediation of PAHs contaminated soils is difficult due to hydrophobic nature of PAHs. Objectives The main purpose of the current study was to determine the pyrene removal efficiency in synthetically contaminated soil, using biosurfactant. Materials and Methods Four pure bacterial strains capable of pyrene degradation were isolated from contaminated soils via enrichment techniques. The soil samples were spiked with an initial pyrene concentration of 500 mg/kg and subjected to bioremediation using a mixed culture comprised of previously isolated strains, in addition to application of biosurfactant during 63 days. Results The pyrene removal efficiency in samples containing biosurfactant, without biosurfactant and controls, were 86.4%, 59.8% and 14%, respectively, after 63 days. The difference of pyrene removal efficiency between the biosurfactant-containing samples and the ones without it was significant (P < 0.05. Conclusions Application of rhamnolipid biosurfactant produced by Pseudomonas aeruginosa significantly improved pyrene removal in contaminated soils.

  10. Biomarkers for monitoring efficacy of bioremediation by microbial inoculants

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, J.K.; Elvang, A.M. [Stockholm University (Sweden). Arrhenius Laboratories for Natural Sciences; Bjorklof, K.; Jorgensen, K.S. [Finnish Environment Institute, Helsinki (Finland). Research Laboratory

    2000-07-01

    Bioaugmentation of contaminated sites with microbes that are adapted or genetically engineered for degradation of specific toxic compounds is an area that is currently being explored as a clean-up option. Biomarkers have been developed to track the survival and efficacy of specific bacteria that are used as inocula for bioremediation of contaminated soil. Examples of biomarkers include the Iuc gene, encoding firefly luciferase and the gfp gene, encoding the green fluorescent protein (GFP). The luc gene was used to tag different bacteria used for bioremediation of gasoline or chlorophenols. The bacteria were monitored on the basis of luciferase activity in cell extracts from soil. The gfp gene was also used to monitor bacteria during degradation of chlorophenol in soil, based on fluorescence of the GFP protein. Other biomarkers can also be used for monitoring of microbial inocula used for bioaugmentation of contaminated sites. The choice of biomarker and monitoring system depends on the particular site, bacterial strain and sensitivity and specificity of detection required. (author)

  11. In situ petroleum hydrocarbon bioremediation in the Canadian Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Greer, C.; Bell, T.; Lee, K.; Delisle, S.; Kovanen, D.; Craig, D.; Juck, D. [National Research Council of Canada, Montreal, PQ (Canada). Biotechnology Research Inst.

    2010-07-01

    This presentation reported on the in-situ bioremediation of diesel contaminated soils at the Canadian Forces Station CFS-Alert, in the Arctic. The soil was amended with monoammonium phosphate (MAP). The operation was designed to take place in a 2 month period during the brief thaw season. This presentation described the installation of the bioventing stacks, the turning of soil, and the application of an oxygen release compound (ORC) at the surface of the permafrost. A significant decrease in petroleum hydrocarbons (PC) was noted over 2 months. The effect of MAP amendment was a slight decrease in biomass in the pristine environment and a significant increase in biomass in the contaminated environment. The alkB gene was found to be important in the biodegradation of alkanes. Stable isotope probing (SIP) was used to identify active organisms. This bioremediation study showed that even in harsh Arctic climates, soils that are moderately contaminated with petroleum hydrocarbons can be remediated effectively and economically via biodegradation. tabs., figs.

  12. Bioremediation of heavy metals using biostimulation in laboratory bioreactor.

    Science.gov (United States)

    Fulekar, M H; Sharma, Jaya; Tendulkar, Akalpita

    2012-12-01

    The present research study investigates bioremediation potential of biostimulated microbial culture isolated from heavy metals waste disposal contaminated site located at Bhayander (east), Mumbai, India. The physicochemical and microbial characterization including heavy metal contaminants have been studied at waste disposal site. The microorganisms adapted at heavy metal-contaminated environment were isolated, cultured, and biostimulated in minimal salt medium under aerobic conditions in a designed and developed laboratory bioreactor. Heavy metals such as Fe, Cu, and Cd at a selected concentration of 25, 50, and 100 μg/ml were taken in bioreactor wherein biostimulated microbial culture was added for bioremediation of heavy metals under aerobic conditions. The remediation of heavy metals was studied at an interval of 24 h for a period of 21 days. The biostimulated microbial consortium has been found effective for remediation of Cd, Cu, and Fe at higher concentration, i.e., 100 mg/l up to 98.5%, 99.6%, and 100%, respectively. Fe being a micronutrient was remediated completely compared to Cu and Cd. During the bioaccumulation of heavy metals by microorganisms, environmental parameters such as pH, total alkalinity, electronic conductivity, biological oxygen demand, chemical oxygen demand, etc. were monitored and assessed. The pilot scale study would be applicable to remediate heavy metals from waste disposal contaminated site to clean up the environment.

  13. The phage-driven microbial loop in petroleum bioremediation.

    Science.gov (United States)

    Rosenberg, Eugene; Bittan-Banin, Gili; Sharon, Gil; Shon, Avital; Hershko, Galit; Levy, Itzik; Ron, Eliora Z

    2010-07-01

    During the drilling process and transport of crude oil, water mixes with the petroleum. At oil terminals, the water settles to the bottom of storage tanks. This drainage water is contaminated with emulsified oil and water-soluble hydrocarbons and must be treated before it can be released into the environment. In this study, we tested the efficiency of a continuous flow, two-stage bioreactor for treating drainage water from an Israeli oil terminal. The bioreactor removed all of the ammonia, 93% of the sulfide and converted 90% of the total organic carbon (TOC) into carbon dioxide. SYBR Gold staining indicated that reactor 1 contained 1.7 × 10(8) bacteria and 3.7 × 10(8) phages per millilitre, and reactor 2 contained 1.3 × 10(8) bacteria and 1.7 × 10(9) phages per millilitre. The unexpectedly high mineralization of TOC and high concentration of phage in reactor 2 support the concept of a phage-driven microbial loop in the bioremediation of the drainage water. In general, application of this concept in bioremediation of contaminated water has the potential to increase the efficiency of processes.

  14. Transformation of a petroleum pollutant during soil bioremediation experiments

    Directory of Open Access Journals (Sweden)

    B. JOVANCICEVIC

    2008-05-01

    Full Text Available The experiment of ex situ soil bioremediation was performed at the locality of the Oil Refinery in Pančevo (alluvial formation of the Danube River, Serbia polluted with an oil type pollutant. The experiments of biostimulation, bioventilation and reinoculation of an autochthonous microbial consortium were performed during the six-month period (May–November 2006. The changes in the quantity and composition of the pollutant, or the bioremediation effect, were monitored by analysis of the samples of the polluted soil taken in time spans of two weeks. In this way, from the beginning until the end of the experiment, 12 samples were collected and marked as P1–P12 (Pančevo 1–Pančevo 12. The results obtained showed that more significant changes in the composition of the oil pollutant occurred only during the last phases of the experiment (P8–P12. The activity of microorganisms was reflected in the increase of the quantity of polar oil fractions, mainly fatty acid fractions. In this way, the quantity of total eluate increased, and the quantity of the insoluble residue was reduced to a minimum, whereby the oil pollutant was transformed to a form that could be removed more efficiently and more completely from the soil, as a segment of the environment.

  15. Degrading and Detoxifying Industrial Waste Water using Bioremediation Approach

    Directory of Open Access Journals (Sweden)

    P. K. Agrawal

    2014-06-01

    Full Text Available Bioremediation uses various microorganisms to detoxify or degrade various harmful substances in the nature, particularly soil and water. In the proposed work, five species of micro-organisms were used to analyse their impact on various physico-chemical parameters of water. In the first attempt the actual physico chemical parameters of the collected sample water were noted down (Fresh sample parameters. Then the sample water was treated with micro-organisms (one at a time. The growth of microbes was noted carefully over 96 hours after inoculation. The physico chemical parameters were recorded again and were compared with the fresh sample parameters. The results were analysed for any change and on this basis an impact factor was developed. The study reveals all the selected microbes have a great capacity of degrading and simplifying the complex molecules into simpler ones. Bioremediative treatment further enhances this capacity and therefore this approach can be utilized on large scale to minimize pollution of water bodies.

  16. Dimensionless parameters to summarize the influence of microbial growth and inhibition on the bioremediation of groundwater contaminants.

    Science.gov (United States)

    Mohamed, M; Hatfield, K

    2011-09-01

    Monod expressions are preferred over zero- and first-order decay expressions in modeling contaminants biotransformation in groundwater because they better represent complex conditions. However, the wide-range of values reported for Monod parameters suggests each case-study is unique. Such uniqueness restricts the usefulness of modeling, complicates an interpretation of natural attenuation and limits the utility of a bioattenuation assessment to a small number of similar cases. In this paper, four Monod-based dimensionless parameters are developed that summarize the effects of microbial growth and inhibition on groundwater contaminants. The four parameters represent the normalized effective microbial growth rate (η), the normalized critical contaminant/substrate concentration (S*), the critical contaminant/substrate inhibition factor (N), and the bioremediation efficacy (η*). These parameters enable contaminated site managers to assess natural attenuation or augmented bioremediation at multiple sites and then draw comparisons between disparate remediation activities, sites and target contaminants. Simulations results are presented that reveal the sensitivity of these dimensionless parameters to Monod parameters and varying electron donor/acceptor loads. These simulations also show the efficacy of attenuation (η*) varying over space and time. Results suggest electron donor/acceptor amendments maintained at relative concentrations S* between 0.5 and 1.5 produce the highest remediation efficiencies. Implementation of the developed parameters in a case study proves their usefulness.

  17. Bioremediation of multi-polluted soil by spent mushroom (Agaricus bisporus) substrate: Polycyclic aromatic hydrocarbons degradation and Pb availability.

    Science.gov (United States)

    García-Delgado, Carlos; Yunta, Felipe; Eymar, Enrique

    2015-12-30

    This study investigates the effect of three spent Agaricus bisporus substrate (SAS) application methods on bioremediation of soil multi-polluted with Pb and PAH from close to a shooting range with respect natural attenuation (SM). The remediation treatments involve (i) use of sterilized SAS to biostimulate the inherent soil microbiota (SSAS) and two bioaugmentation possibilities (ii) its use without previous treatment to inoculate A. bisporus and inherent microbiota (SAS) or (iii) SAS sterilization and further A. bisporus re-inoculation (Abisp). The efficiency of each bioremediation microcosm was evaluated by: fungal activity, heterotrophic and PAH-degrading bacterial population, PAH removal, Pb mobility and soil eco-toxicity. Biostimulation of the native soil microbiology (SSAS) achieved similar levels of PAH biodegradation as SM and poor soil detoxification. Bioaugmented microcosms produced higher PAH removal and eco-toxicity reduction via different routes. SAS increased the PAH-degrading bacterial population, but lowered fungal activity. Abisp was a good inoculum carrier for A. bisporus exhibiting high levels of ligninolytic activity, the total and PAH-degrading bacteria population increased with incubation time. The three SAS applications produced slight Pb mobilization (bisporus re-inoculation (Abisp) proved the best application method to remove PAH, mainly BaP, and detoxify the multi-polluted soil.

  18. The application of a mulch biofilm barrier for surfactant enhanced polycyclic aromatic hydrocarbon bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Youngwoo; Lee, Woo-Hyung; Sorial, George [Department of Civil and Environmental Engineering, University of Cincinnati, 765 Baldwin Hall, PO Box 210071, Cincinnati, OH 45221-0071 (United States); Bishop, Paul L. [Department of Civil and Environmental Engineering, University of Cincinnati, 765 Baldwin Hall, PO Box 210071, Cincinnati, OH 45221-0071 (United States)], E-mail: Paul.Bishop@UC.edu

    2009-01-15

    Lab scale mulch biofilm barriers were constructed and tested to evaluate their performance for preventing the migration of aqueous and surfactant solubilized PAHs. The spatial distribution of viable PAH degrader populations and resultant biofilm formation were also monitored to evaluate the performance of the biobarrier and the prolonged surfactant effect on the PAH degrading microorganism consortia in the biobarrier. Sorption and biodegradation of PAHs resulted in stable operation of the system for dissolved phenanthrene and pyrene during 150 days of experimentation. The nonionic surfactant could increase the solubility of phenanthrene and pyrene significantly. However, the biobarrier itself couldn't totally prevent the migration of micellar solubilized phenanthrene and pyrene. The presence of surfactant and the resultant highly increased phenanthrene or pyrene concentration didn't appear to cause toxic effects on the attached biofilm in the biobarrier. However, the presence of surfactant did change the structural composition of the biofilm. - Mulch biofilm barrier showed potential for surfactant enhanced bioremediation, and the presence of surfactant changed the structural composition of the biofilm.

  19. Hydrogeophysical imaging of deposit heterogeneity and groundwater chemistry changes during DNAPL source zone bioremediation

    Science.gov (United States)

    Chambers, J. E.; Wilkinson, P. B.; Wealthall, G. P.; Loke, M. H.; Dearden, R.; Wilson, R.; Allen, D.; Ogilvy, R. D.

    2010-10-01

    Robust characterization and monitoring of dense nonaqueous phase liquid (DNAPL) source zones is essential for designing effective remediation strategies, and for assessing the efficacy of treatment. In this study high-resolution cross-hole electrical resistivity tomography (ERT) was evaluated as a means of monitoring a field-scale in-situ bioremediation experiment, in which emulsified vegetable oil (EVO) electron donor was injected into a trichloroethene source zone. Baseline ERT scans delineated the geometry of the interface between the contaminated alluvial aquifer and the underlying mudstone bedrock, and also the extent of drilling-induced physical heterogeneity. Time-lapse ERT images revealed major preferential flow pathways in the source and plume zones, which were corroborated by multiple lines of evidence, including geochemical monitoring and hydraulic testing using high density multilevel sampler arrays within the geophysical imaging planes. These pathways were shown to control the spatial distribution of the injected EVO, and a bicarbonate buffer introduced into the cell for pH control. Resistivity signatures were observed within the preferential flow pathways that were consistent with elevated chloride levels, providing tentative evidence from ERT of the biodegradation of chlorinated solvents.

  20. Synergistic effects of bioremediation and electrokinetics in the remediation of petroleum-contaminated soil.

    Science.gov (United States)

    Guo, Shuhai; Fan, Ruijuan; Li, Tingting; Hartog, Niels; Li, Fengmei; Yang, Xuelian

    2014-08-01

    The present study evaluated the coupling interactions between bioremediation (BIO) and electrokinetics (EK) in the remediation of total petroleum hydrocarbons (TPH) by using bio-electrokinetics (BIO-EK) with a rotatory 2-D electric field. The results demonstrated an obvious positive correlation between the degradation extents of TPH and electric intensity both in the EK and BIO-EK tests. The use of BIO-EK showed a significant improvement in degradation of TPH as compared to BIO or EK alone. The actual degradation curve in BIO-EK tests fitted well with the simulated curve obtained by combining the degradation curves in BIO- and EK-only tests during the first 60 d, indicating a superimposed effect of biological degradation and electrochemical stimulation. The synergistic effect was particularly expressed during the later phase of the experiment, concurrent with changes in the microbial community structure. The community composition changed mainly according to the duration of the electric field, leading to a reduction in diversity. No significant spatial shifts in microbial community composition and bacterial numbers were detected among different sampling positions. Soil pH was uniform during the experimental process, soil temperature showed no variations between the soil chambers with and without an electric field.

  1. Bioremediation of Metals and Radionuclides: What It Is and How It Works (2nd Edition)

    Energy Technology Data Exchange (ETDEWEB)

    Palmisano, Anna; Hazen, Terry

    2003-09-30

    This primer is intended for people interested in environmental problems of the U.S. Department of Energy (DOE) and in their potential solutions. It will specifically look at some of the more hazardous metal and radionuclide contaminants found on DOE lands and at the possibilities for using bioremediation technology to clean up these contaminants. The second edition of the primer incorporates recent findings by researchers in DOE's Natural and Accelerated Bioremediation Research (NABIR) Program. Bioremediation is a technology that can be used to reduce, eliminate, or contain hazardous waste. Over the past two decades, it has become widely accepted that microorganisms, and to a lesser extent plants, can transform and degrade many types of contaminants. These transformation and degradation processes vary, depending on the physical-chemical environment, microbial communities, and nature of the contaminant. This technology includes intrinsic bioremediation, which relies on naturally occurring processes, and accelerated bioremediation, which enhances microbial degradation or transformation through the addition of nutrients (biostimulation) or inoculation with microorganisms (bioaugmentation). Over the past few years, interest in bioremediation has increased. It has become clear that many organic contaminants such as hydrocarbon fuels can be degraded to relatively harmless products such as CO{sub 2} (the end result of the degradation process). Waste water managers and scientists have also found that microorganisms can interact with metals and convert them from one chemical form to another. Laboratory tests and ex situ bioremediation applications have shown that microorganisms can change the valence, or oxidation state, of some heavy metals (e.g., chromium and mercury) and radionuclides (e.g., uranium) by using them as electron acceptors. In some cases, the solubility of the altered species decreases and the contaminant is immobilized in situ, i.e., precipitated into

  2. SPATIAL STABILITY

    OpenAIRE

    Pascal Mossay

    2004-01-01

    We consider a continuous spatial economy consisting of pure exchange local economies. Agents are allowed to change their location over time as a response to spatial utility differentials. These spatial adjustments toward higher utility neighborhoods lead the spatial economy to converge to a spatially uniform allocation of resources, provided that the matrix of price effects is quasi-negative definite. Furthermore our model provides a real time interpretation of the tâtonnement story. Also, sp...

  3. Bioremediation of Mixtures of High Molecular Weight Polycyclic Aromatic Hydrocarbons

    Science.gov (United States)

    Xu, H.; Wu, J.; Shi, X.; Sun, Y.

    2014-12-01

    Although bioremediation has been considered as one of the most promising means to remove polycyclic aromatic hydrocarbons (PAHs) from polluted environments, the efficacy of PAHs bioremediation still remains challenged, especially for high molecular weight PAHs (HMW PAHs) and their mixtures. This study was focused on (a) isolation and characterization of pure strain and mixed microbial communities able to degrade HMW PAHs and (b) further evaluation of the ability of the isolated microbes to degrade HMW PAHs mixtures in the absence and presence of indigenous flora. Fluoranthene, benzo[b]fluoranthene and pyrene were selected as the representative HMW PAHs in this study. A pure bacterial strain, identified as Herbaspirillum chlorophenolicum FA1, was isolated from activated sludge. A mixed bacterial community designated as consortium-4 was isolated from petroleum contaminated soils, containing Pseudomonas sp. FbP1、Enterobacter sp. FbP2、Hydrogenophaga sp. FbP3 and Luteolibacter pohnpeiensis. FbP4. To our knowledge, this is the first study to demonstrate that bacterial strains of Herbaspirillum chlorophenolicum FA1 and Luteolibacter pohnpeiensis. FbP4 can also degrade fluoranthene, benzo[b]fluoranthene and pyrene. Experiment results showed that both strain FA1 and consortium-4 could degrade fluoranthene, benzo[b]fluoranthene and pyrene within a wide range of temperature, pH and initial PAHs concentration. Degradation of HMW PAHs mixtures (binary and ternary) demonstrated the interactive effects that can alter the rate and extent of biodegradation within a mixture. The presence of indigenous flora was found to either increase or decrease the degradation of HMW PAHs, suggesting possible synergistic or competition effects. Biodegradation kinetics of HMW PAHs for sole substrates, binary and ternary systems was evaluated, with the purpose to better characterize and compare the biodegradation process of individual HMW PAH and mixtures of HMW PAHs. Results of this study

  4. A Functional Genomic Approach to Chlorinated Ethenes Bioremediation

    Science.gov (United States)

    Lee, P. K.; Brodie, E. L.; MacBeth, T. W.; Deeb, R. A.; Sorenson, K. S.; Andersen, G. L.; Alvarez-Cohen, L.

    2007-12-01

    With the recent advances in genomic sciences, a knowledge-based approach can now be taken to optimize the bioremediation of trichloroethene (TCE). During the bioremediation of a heterogeneous subsurface, it is vital to identify and quantify the functionally important microorganisms present, characterize the microbial community and measure their physiological activity. In our field experiments, quantitative PCR (qPCR) was coupled with reverse-transcription (RT) to analyze both copy numbers and transcripts expressed by the 16S rRNA gene and three reductive dehalogenase (RDase) genes as biomarkers of Dehalococcoides spp. in the groundwater of a TCE-DNAPL site at Ft. Lewis (WA) that was serially subjected to biostimulation and bioaugmentation. Genes in the Dehalococcoides genus were targeted as they are the only known organisms that can completely dechlorinate TCE to the innocuous product ethene. Biomarker quantification revealed an overall increase of more than three orders of magnitude in the total Dehalococcoides population and quantification of the more liable and stringently regulated mRNAs confirmed that Dehalococcoides spp. were active. Parallel with our field experiments, laboratory studies were conducted to explore the physiology of Dehalococcoides isolates in order to develop relevant biomarkers that are indicative of the metabolic state of cells. Recently, we verified the function of the nitrogenase operon in Dehalococcoides sp. strain 195 and nitrogenase-encoding genes are ideal biomarker targets to assess cellular nitrogen requirement. To characterize the microbial community, we applied a high-density phylogenetic microarray (16S PhyloChip) that simultaneous monitors over 8,700 unique taxa to track the bacterial and archaeal populations through different phases of treatment. As a measure of species richness, 1,300 to 1,520 taxa were detected in groundwater samples extracted during different stages of treatment as well as in the bioaugmentation culture. We

  5. SITE TECHNOLOGY CAPSULE: J.R. SIMPLOT EX-SITU BIOREMEDIATION TECHNOLOGY: DINOSEB

    Science.gov (United States)

    The J.R. Simplot Ex-Situ Bioremediation Technology is designed to anaerobically degrade nitroaromatic and energetic compounds in soils and liquids without forming identifiable toxic intermediate compounds produced by other biotreatment methods. This technology was evaluated un...

  6. SITE TECHNOLOGY CAPSULE: GRACE DEARBORN INC.'S DARAMEND BIOREMEDIATION TECHNOLOGY

    Science.gov (United States)

    Grace Dearborn's DARAMEND Bioremediation Technology was developed to treat soils/sediment contaminated with organic contaminants using solid-phase organic amendments. The amendments increase the soil's ability to supply biologically available water/nutrients to microorganisms and...

  7. NATURAL BIOREMEDIATION PERSPECTIVE FOR BTX CONTAMINATED GROUNDWATER IN BRAZIL: EFFECT OF ETHANOL (R823420)

    Science.gov (United States)

    AbstractNatural bioremediation, the use of indigenous microorganisms to degrade hazardous substances within aquifers without engineered stimulation, shows great promise as a cost-effective approach to hydrocarbon plume management. This technique requires thorough site...

  8. Augmented In Situ Subsurface Bioremediation Process™BIO-REM, Inc. - Demonstration Bulletin

    Science.gov (United States)

    The Augmented In Situ Subsurface Bioremediation Process™ developed by BIO-REM, Inc., uses microaerophilic bacteria and micronutrients (H-10) and surface tension depressants/penetrants for the treatment of hydrocarbon contaminated soils and groundwater. The bacteria utilize hydroc...

  9. STUDIES ON BIOREMEDIATION OF POLYCYCLIC AROMATIC HYDROCARBON-CONTAMINATED SEDIMENTS: BIOAVAILABILITY, BIODEGRADABILITY, AND TOXICITY ISSUES

    Science.gov (United States)

    The widespread contamination of aquatic sediments by polycyclic aromatic hydrocarbons (PAHs) has created a need for cost-effective bioremediation processes, on which the bioavailability and the toxicity of PAHs often have a significant impact. This research investigated the biode...

  10. Bioremediation of metals and radionuclides: What it is and How itWorks

    Energy Technology Data Exchange (ETDEWEB)

    McCullough, J.; Hazen, Terry; Benson, Sally

    1999-01-01

    This primer is intended for people interested in DOE environmental problems and in their potential solutions. It will specifically look at some of the more hazardous metal and radionuclide contaminants found on DOE lands and at the possibilities for using bioremediation technology to clean up these contaminants. Bioremediation is a technology that can be used to reduce, eliminate, or contain hazardous waste. Over the past two decades, it has become widely accepted that microorganisms, and to a lesser extent plants, can transform and degrade many types of contaminants. These transformation and degradation processes vary, depending on physical environment, microbial communities, and nature of contaminant. This technology includes intrinsic bioremediation, which relies on naturally occurring processes, and accelerated bioremediation, which enhances microbial degradation or transformation through inoculation with microorganisms (bioaugmentation) or the addition of nutrients (biostimulation).

  11. Integrated water quality, emergy and economic evaluation of three bioremediation treatment systems for eutrophic water

    Science.gov (United States)

    This study was targeted at finding one or more environmentally efficient, economically feasible and ecologically sustainable bioremediation treatment modes for eutrophic water. Three biological species, i.e. water spinach (Ipomoea aquatica), loach (Misgurus anguillicaudatus) and ...

  12. Bioremediation of waste under ocean acidification: Reviewing the role of Mytilus edulis.

    Science.gov (United States)

    Broszeit, Stefanie; Hattam, Caroline; Beaumont, Nicola

    2016-02-15

    Waste bioremediation is a key regulating ecosystem service, removing wastes from ecosystems through storage, burial and recycling. The bivalve Mytilus edulis is an important contributor to this service, and is used in managing eutrophic waters. Studies show that they are affected by changes in pH due to ocean acidification, reducing their growth. This is forecasted to lead to reductions in M. edulis biomass of up to 50% by 2100. Growth reduction will negatively affect the filtering capacity of each individual, potentially leading to a decrease in bioremediation of waste. This paper critically reviews the current state of knowledge of bioremediation of waste carried out by M. edulis, and the current knowledge of the resultant effect of ocean acidification on this key service. We show that the effects of ocean acidification on waste bioremediation could be a major issue and pave the way for empirical studies of the topic.

  13. BIOREMEDIATION OF HAZARDOUS WASTE SITES: PRACTICAL APPROACHES TO IMPLEMENTATION (EPA/625/K-96/001)

    Science.gov (United States)

    This document contains abstracts and slide hardcopy for the U.S. Environmental Protection Agency's (EPA's) "Seminar Series on Bioremediation of Hazardous Waste Sites: Practical Approaches to Implementation." This technology transfer seminar series, sponsored by EPA's Biosystems ...

  14. Insight in the PCB-degrading functional community in long-term contaminated soil under bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Petric, Ines; Hrsak, Dubravka; Udikovic-Kolic, Nikolina [Ruder Boskovic Inst., Division for Marine and Environmental Research, Zagreb (Croatia); Fingler, Sanja [Inst. for Medical Research and Occupational Health, Zagreb (Croatia); Bru, David; Martin-Laurent, Fabrice [INRA, Univ. der Bourgogne, Soil and Environmental Microbiology, Dijon (France)

    2011-02-15

    A small-scale bioremediation assay was developed in order to get insight into the functioning of a polychlorinated biphenyl (PCB) degrading community during the time course of bioremediation treatment of a contaminated soil. The study was conducted with the aim to better understand the key mechanisms involved in PCB-removal from soils. Materials and methods Two bioremediation strategies were applied in the assay: (a) biostimulation (addition of carvone as inducer of biphenyl pathway, soya lecithin for improving PCB bioavailability, and xylose as supplemental carbon source) and (b) bioaugmentation with selected seed cultures TSZ7 or Rhodococcus sp. Z6 originating from the transformer station soil and showing substantial PCB-degrading activity. Functional PCB-degrading community was investigated by using molecular-based approaches (sequencing, qPCR) targeting bphA and bphC genes, coding key enzymes of the upper biphenyl pathway, in soil DNA extracts. In addition, kinetics of PCBs removal during the bioremediation treatment was determined using gas chromatography mass spectrometry analyses. Results and discussion bphA-based phylogeny revealed that bioremediation affected the structure of the PCB-degrading community in soils, with Rhodococcus-like bacterial populations developing as dominant members. Tracking of this population further indicated that applied bioremediation treatments led to its enrichment within the PCB-degrading community. The abundance of the PCB-degrading community, estimated by quantifying the copy number of bphA and bphC genes, revealed that it represented up to 0.3% of the total bacterial community. All bioremediation treatments were shown to enhance PCB reduction in soils, with approximately 40% of total PCBs being removed during a 1-year period. The faster PCB reduction achieved in bioaugmented soils suggested an important role of the seed cultures in bioremediation processes. Conclusions The PCBs degrading community was modified in response to

  15. Petroleum-Degrading Enzymes: Bioremediation and New Prospects

    Directory of Open Access Journals (Sweden)

    R. S. Peixoto

    2011-01-01

    Full Text Available Anthropogenic forces, such as petroleum spills and the incomplete combustion of fossil fuels, have caused an accumulation of petroleum hydrocarbons in the environment. The accumulation of petroleum and its derivatives now constitutes an important environmental problem. Biocatalysis introduces new ways to improve the development of bioremediation strategies. The recent application of molecular tools to biocatalysis may improve bioprospecting research, enzyme yield recovery, and enzyme specificity, thus increasing cost-benefit ratios. Enzymatic remediation is a valuable alternative as it can be easier to work with than whole organisms, especially in extreme environments. Furthermore, the use of free enzymes avoids the release of exotic or genetically modified organisms (GMO in the environment.

  16. Soil Bioremediation Strategies Based on the Use of Fungal Enzymes

    Science.gov (United States)

    Mougin, Christian; Boukcim, Hassan; Jolivalt, Claude

    The pollution of soil due to chemical compounds is an important problem worldwide. For that reason, the development of bioremediation processes remains an important challenge. In that context, filamentous fungi and their enzymatic systems appear to be potent tools to decrease the levels of contaminants in soils, by contaminant degradation or stabilisation. The structures and modes of action of selected fungal enzymes, namely peroxidases and laccases, have been extensively studied and are now well-known. Nevertheless, some improvement of their catalytic characteristics can be attempted through genetic engineering, in order to develop specific properties. In addition, some research is still needed to overcome several of their limitations for their efficient use in soils.

  17. Engineering microbial consortia to enhance biomining and bioremediation

    Directory of Open Access Journals (Sweden)

    Karl Dietrich Brune

    2012-06-01

    Full Text Available In natural environments microorganisms commonly exist as communities of multiple species that are capable of performing more varied and complicated tasks than clonal populations. Synthetic biologists have engineered clonal populations with characteristics such as differentiation, memory and pattern formation, which are usually associated with more complex multicellular organisms. The prospect of designing microbial communities has alluring possibilities for environmental, biomedical and energy applications and is likely to reveal insight into how natural microbial consortia function. Cell signaling and communication pathways between different species are likely to be key processes for designing novel functions in synthetic and natural consortia. Recent efforts to engineer synthetic microbial interactions will be reviewed here, with particular emphasis given to research with significance for industrial applications in the field of biomining and bioremediation of acid mine drainage.

  18. Intrinsic bioremediation potential of a chronically polluted marine coastal area.

    Science.gov (United States)

    Catania, Valentina; Santisi, Santina; Signa, Geraldina; Vizzini, Salvatrice; Mazzola, Antonio; Cappello, Simone; Yakimov, Michail M; Quatrini, Paola

    2015-10-15

    A microbiological survey of the Priolo Bay (eastern coast of Sicily, Ionian Sea), a chronically polluted marine coastal area, was carried out in order to discern its intrinsic bioremediation potential. Microbiological analysis, 16S rDNA-based DGGE fingerprinting and PLFAs analysis were performed on seawater and sediment samples from six stations on two transects. Higher diversity and variability among stations was detected by DGGE in sediment than in water samples although seawater revealed higher diversity of culturable hydrocarbon-degrading bacteria. The most polluted sediment hosted higher total bacterial diversity and higher abundance and diversity of culturable HC degraders. Alkane- and PAH-degrading bacteria were isolated from all stations and assigned to Alcanivorax, Marinobacter, Thalassospira, Alteromonas and Oleibacter (first isolation from the Mediterranean area). High total microbial diversity associated to a large selection of HC degraders is believed to contribute to natural attenuation of the area, provided that new contaminant contributions are avoided.

  19. Removing environmental organic pollutants with bioremediation and phytoremediation.

    Science.gov (United States)

    Kang, Jun Won

    2014-06-01

    Hazardous organic pollutants represent a threat to human, animal, and environmental health. If left unmanaged, these pollutants could cause concern. Many researchers have stepped up efforts to find more sustainable and cost-effective alternatives to using hazardous chemicals and treatments to remove existing harmful pollutants. Environmental biotechnology, such as bioremediation and phytoremediation, is a promising field that utilizes natural resources including microbes and plants to eliminate toxic organic contaminants. This technology offers an attractive alternative to other conventional remediation processes because of its relatively low cost and environmentally-friendly method. This review discusses current biological technologies for the removal of organic contaminants, including chlorinated hydrocarbons, focusing on their limitation and recent efforts to correct the drawbacks.

  20. Enhanced bioremediation of oil spills in the sea.

    Science.gov (United States)

    Ron, Eliora Z; Rosenberg, Eugene

    2014-06-01

    Hydrocarbon-degrading bacteria are ubiquitous in the sea, including hydrocarbonoclastic bacteria that utilize hydrocarbons almost exclusively as carbon and energy sources. However, the rates at which they naturally degrade petroleum following an oil spill appear to be too slow to prevent oil from reaching the shore and causing environmental damage, as has been documented in the Exxon Valdez and Gulf of Mexico disasters. Unfortunately, there is, at present, no experimentally demonstrated methodology for accelerating the degradation of hydrocarbons in the sea. The rate-limiting factor for petroleum degradation in the sea is availability of nitrogen and phosphorus. Oleophilic fertilizers, such as Inipol EAP 22 and urea-formaldehyde polymers, have stimulated hydrocarbon degradation on shorelines but are less effective in open systems. We suggest uric acid as a potentially useful fertilizer enhancing bioremediation at sea.

  1. Rhamnolipids enhance marine oil spill bioremediation in laboratory system.

    Science.gov (United States)

    Chen, Qingguo; Bao, Mutai; Fan, Xiaoning; Liang, Shengkang; Sun, Peiyan

    2013-06-15

    This paper presents a simulated marine oil spill bioremediation experiment using a bacterial consortium amended with rhamnolipids. The role of rhamnolipids in enhancing hydrocarbon biodegradation was evaluated via GC-FID and GC-MS analysis. Rhamnolipids enhanced total oil biodegradation efficiency by 5.63%, with variation in normal alkanes, polyaromatic hydrocarbons (PAHs) and biomakers biodegradation. The hydrocarbons biodegradation by bacteria consortium overall follows a decreasing order of PAHs>n-alkanes>biomarkers, while in different order of PAHs>biomarkers>n-alkanes when rhamnolipids was used, and the improvement in the removal efficiency by rhamnolipids follows another order of biomarkers>n-alkanes>PAHs. Rhamnolipids played a negative role in degradation of those hydrocarbons with relatively volatile property, such as n-alkanes with short chains, PAHs and sesquiterpenes with simple structure. As to the long chain normal alkanes and PAHs and biomakers with complex structure, the biosurfactant played a positive role in these hydrocarbons biodegradation.

  2. UTILIZING Aspergillus niger FOR BIOREMEDIATION OF TANNERY EFFLUENT

    Directory of Open Access Journals (Sweden)

    Jyoti Bisht

    2014-03-01

    Full Text Available Tannery waste water is characterized by highly toxic ammonium, sulfates, surfactants, acids, dyes, sulfonated oils and organic substances, including natural or synthetic tannins. This study was designed to study the potential of Aspergillus niger for bioremediation of tannery effluent. Addition of glucose as a carbon source in the tannery effluent encouraged the growth of A. niger but there was no change in physico-chemical parameters. The toxic effects were mostly reduced after treatment when 20% mineral salt medium was added in tannery effluent. Colour, COD, TS, TDS, TSS, chlorides, sulfides and chromium reduction were 71.9%, 72.1%, 69.0%, 65.0%, 68.1%, 66.8%, 65.7% and 57.8%, respectively.

  3. An evaluation of in-situ bioremediation processes

    Energy Technology Data Exchange (ETDEWEB)

    Cole, L.L. [Prairie View A and M Univ., TX (United States); Rashidi, M. [Lawrence Livermore National Lab., CA (United States). Environmental Programs Directorate

    1996-08-01

    Remediation of petroleum hydrocarbons in groundwater was the primary focus in the initial application of in-situ bioremediation which, from its development in the 1970s, has grown to become one of the most promising technologies for the degradation of a wide variety of organic contaminants. The degradation of contaminants in subsurface soils is the current new focus of the technology. While the need for improvements in the technology does exist, the indisputable fact remains that this technology is by far the least expensive and that it has the capability to provide long term reduced levels of contaminants or long term complete remediation of contaminated sites. The aim of this paper is to disclose pertinent information related to current conditions and current feelings in the area of new research, novel applications, new government regulations, and an overview of new topics on the horizon that relate to the overall technology.

  4. Role of Microbial Enzymes in the Bioremediation of Pollutants: A Review

    OpenAIRE

    Karigar, Chandrakant S.; Rao, Shwetha S.

    2011-01-01

    A large number of enzymes from bacteria, fungi, and plants have been reported to be involved in the biodegradation of toxic organic pollutants. Bioremediation is a cost effective and nature friendly biotechnology that is powered by microbial enzymes. The research activity in this area would contribute towards developing advanced bioprocess technology to reduce the toxicity of the pollutants and also to obtain novel useful substances. The information on the mechanisms of bioremediation-related...

  5. Bacterial Community Dynamics and Polycyclic Aromatic Hydrocarbon Degradation during Bioremediation of Heavily Creosote-Contaminated Soil

    OpenAIRE

    Viñas, Marc; Sabaté, Jordi; Espuny, María José; Solanas, Anna M.

    2005-01-01

    Bacterial community dynamics and biodegradation processes were examined in a highly creosote-contaminated soil undergoing a range of laboratory-based bioremediation treatments. The dynamics of the eubacterial community, the number of heterotrophs and polycyclic aromatic hydrocarbon (PAH) degraders, and the total petroleum hydrocarbon (TPH) and PAH concentrations were monitored during the bioremediation process. TPH and PAHs were significantly degraded in all treatments (72 to 79% and 83 to 87...

  6. Bioremediation: Hope/Hype for Environmental Cleanup (LBNL Summer Lecture Series)

    Energy Technology Data Exchange (ETDEWEB)

    Hazen, Terry [LBNL, Ecology Dept

    2007-07-18

    Summer Lecture Series 2007: Terry Hazen, Senior Staff Scientists and Head of the LBNL Ecology Department, discusses when it's best to resort to engineered bioremediation of contaminated sites, and when it's best to rely on natural attenuation. Recent advances have greatly broadened the potential applications for bioremediation. At the same time, scientists' knowledge of biogeochemical processes has advanced and they can better gauge how quickly and completely contaminants can be degraded without human intervention.

  7. Impact of Groundwater Salinity on Bioremediation Enhanced by Micro-Nano Bubbles

    OpenAIRE

    2013-01-01

    Micro-nano bubbles (MNBs) technology has shown great potential in groundwater bioremediation because of their large specific surface area, negatively charged surface, long stagnation, high oxygen transfer efficiency, etc. Groundwater salinity, which varies from sites due to different geological and environmental conditions, has a strong impact on the bioremediation effect. However, the groundwater salinity effect on MNBs’ behavior has not been reported. In this study, the size distribution, o...

  8. Assessing in situ rates of anaerobic hydrocarbon bioremediation.

    Science.gov (United States)

    Gieg, Lisa M; Alumbaugh, Robert E; Field, Jennifer; Jones, Jesse; Istok, Jonathon D; Suflita, Joseph M

    2009-03-01

    Identifying metabolites associated with anaerobic hydrocarbon biodegradation is a reliable way to garner evidence for the intrinsic bioremediation of problem contaminants. While such metabolites have been detected at numerous sites, the in situ rates of anaerobic hydrocarbon decay remain largely unknown. Yet, realistic rate information is critical for predicting how long individual contaminants will persist and remain environmental threats. Here, single-well push-pull tests were conducted at two fuel-contaminated aquifers to determine the in situ biotransformation rates of a suite of hydrocarbons added as deuterated surrogates, including toluene-d(8), o-xylene-d(10), m-xylene-d(10), ethylbenzene-d(5) (or -d(10)), 1, 2, 4-trimethylbenzene-d(12), 1, 3, 5-trimethylbenzene-d(12), methylcyclohexane-d(14) and n-hexane-d(14). The formation of deuterated fumarate addition and downstream metabolites was quantified and found to be somewhat variable among wells in each aquifer, but generally within an order of magnitude. Deuterated metabolites formed in one aquifer at rates that ranged from 3 to 50 µg l(-1) day(-1), while the comparable rates at another aquifer were slower and ranged from 0.03 to 15 µg l(-1) day(-1). An important observation was that the deuterated hydrocarbon surrogates were metabolized in situ within hours or days at both sites, in contrast to many laboratory findings suggesting that long lag periods of weeks to months before the onset of anaerobic biodegradation are typical. It seems clear that highly reduced conditions are not detrimental to the intrinsic bioremediation of fuel-contaminated aquifers.

  9. Bioremediation of industrially contaminated soil using compost and plant technology.

    Science.gov (United States)

    Taiwo, A M; Gbadebo, A M; Oyedepo, J A; Ojekunle, Z O; Alo, O M; Oyeniran, A A; Onalaja, O J; Ogunjimi, D; Taiwo, O T

    2016-03-05

    Compost technology can be utilized for bioremediation of contaminated soil using the active microorganisms present in the matrix of contaminants. This study examined bioremediation of industrially polluted soil using the compost and plant technology. Soil samples were collected at the vicinity of three industrial locations in Ogun State and a goldmine site in Iperindo, Osun State in March, 2014. The compost used was made from cow dung, water hyacinth and sawdust for a period of twelve weeks. The matured compost was mixed with contaminated soil samples in a five-ratio pot experimental design. The compost and contaminated soil samples were analyzed using the standard procedures for pH, electrical conductivity (EC), organic carbon (OC), total nitrogen (TN), phosphorus, exchangeable cations (Na, K, Ca and Mg) and heavy metals (Fe, Mn, Cu, Zn and Cr). Kenaf (Hibiscus cannabinus) seeds were also planted for co-remediation of metals. The growth parameters of Kenaf plants were observed weekly for a period of one month. Results showed that during the one-month remediation experiment, treatments with 'compost-only' removed 49 ± 8% Mn, 32 ± 7% Fe, 29 ± 11% Zn, 27 ± 6% Cu and 11 ± 5% Cr from the contaminated soil. On the other hand, treatments with 'compost+plant' remediated 71 ± 8% Mn, 63 ± 3% Fe, 59 ± 11% Zn, 40 ± 6% Cu and 5 ± 4% Cr. Enrichment factor (EF) of metals in the compost was low while that of Cu (EF=7.3) and Zn (EF=8.6) were high in the contaminated soils. Bioaccumulation factor (BF) revealed low metal uptake by Kenaf plant. The growth parameters of Kenaf plant showed steady increments from week 1 to week 4 of planting.

  10. Correlation between social proximity and mobility similarity

    CERN Document Server

    Fan, Chao; Huang, Junming; Rong, Zhihai; Zhou, Tao

    2016-01-01

    Human behaviors exhibit ubiquitous correlations in many aspects, such as individual and collective levels, temporal and spatial dimensions, content, social and geographical layers. With rich Internet data of online behaviors becoming available, it attracts academic interests to explore human mobility similarity from the perspective of social network proximity. Existent analysis shows a strong correlation between online social proximity and offline mobility similari- ty, namely, mobile records between friends are significantly more similar than between strangers, and those between friends with common neighbors are even more similar. We argue the importance of the number and diversity of com- mon friends, with a counter intuitive finding that the number of common friends has no positive impact on mobility similarity while the diversity plays a key role, disagreeing with previous studies. Our analysis provides a novel view for better understanding the coupling between human online and offline behaviors, and will...

  11. Effects on lead bioavailability and plant uptake during the bioremediation of soil PAHs

    Energy Technology Data Exchange (ETDEWEB)

    Amezcua-Allieri, M.A. [Inst. Politecnico Nacional, Mexico City (Mexico); Rodriguez-Vazquez, R. [CINVESTAV, Mexico City (Mexico)

    2008-07-01

    Polycyclic aromatic hydrocarbons (PAHs) are a group of priority pollutants that are present in the soils of many industrially contaminated sites. In Mexico, the petrochemical industry is the main source of soil pollution. Soils polluted with PAHs are often accompanied by high levels of metals. Although bioremediation of soil contaminated with PAHs have received increasing attentions, the influence of microbial activity on metal behaviour is not understood. For that reason, this study investigated lead behaviour during the bioremoval of phenanthrene in soils sampled from Tabasco, Mexico. Lead bioavailable concentrations were evaluated by diffusive gradients in thin-films (DGT). Metal uptake to plants was quantified. Lead concentrations were determined before and after organic removal by Penicillium frequentans and soil microflora. Metal uptake by Echinochloa polystachya and Triticum aestivum L was also investigated. DGT concentrations increased significantly after the addition of fungi in the presence of plants before bioremediation and after fungal addition. Although DGT responded immediately to uptake, plant uptake did not begin immediately. The fungal bioremediation reduced organic contaminants significantly while it increased bioavailable metal concentrations and plant uptake. The results highlight the impact of bioremediation of organic contaminants on trace metal behaviour. The bioremediation process makes the toxic lead more available to plants, and therefore more metal may be incorporated into the human food chain if crops grown on bioremediated soil are used for human or animal consumption. 15 refs., 3 figs.

  12. Changes in microbial populations and enzyme activities during the bioremediation of oil-contaminated soil.

    Science.gov (United States)

    Lin, Xin; Li, Xiaojun; Sun, Tieheng; Li, Peijun; Zhou, Qixing; Sun, Lina; Hu, Xiaojun

    2009-10-01

    In the process of bioremediation in the soil contaminated by different oil concentrations, the changes in the microbial numbers (bacteria and fungi) and the enzyme (catalase (CAT), polyphenol oxidase (PPO) and lipase) activities were evaluated over a 2-year period. The results showed that the microbial numbers after 2-year bioremediation were one to ten times higher than those in the initial. The changes in the bacterial and the fungal populations were different during the bioremediation, and the highest microbial numbers for bacteria and fungi were 5.51 x 10(9) CFU g(-1) dry soil in treatment 3 (10,000 mg kg(-1)) in the initial and 5.54 x 10(5) CFU g(-1) dry soil in treatment 5 (50,000 mg kg(-1)) after the 2-year bioremediation period, respectively. The CAT and PPO activities in the contaminated soil decreased with increasing oil concentration, while the lipase activity increased. The activities of CAT and PPO improved after the bioremediation, but lipase activity was on the contrary. The CAT activity was more sensible to the oil than others, and could be alternative to monitor the bioremediation process.

  13. Ecotoxicity monitoring and bioindicator screening of oil-contaminated soil during bioremediation.

    Science.gov (United States)

    Shen, Weihang; Zhu, Nengwu; Cui, Jiaying; Wang, Huajin; Dang, Zhi; Wu, Pingxiao; Luo, Yidan; Shi, Chaohong

    2016-02-01

    A series of toxicity bioassays was conducted to monitor the ecotoxicity of soils in the different phases of bioremediation. Artificially oil-contaminated soil was inoculated with a petroleum hydrocarbon-degrading bacterial consortium containing Burkholderia cepacia GS3C, Sphingomonas GY2B and Pandoraea pnomenusa GP3B strains adapted to crude oil. Soil ecotoxicity in different phases of bioremediation was examined by monitoring total petroleum hydrocarbons, soil enzyme activities, phytotoxicity (inhibition of seed germination and plant growth), malonaldehyde content, superoxide dismutase activity and bacterial luminescence. Although the total petroleum hydrocarbon (TPH) concentration in soil was reduced by 64.4%, forty days after bioremediation, the phytotoxicity and Photobacterium phosphoreum ecotoxicity test results indicated an initial increase in ecotoxicity, suggesting the formation of intermediate metabolites characterized by high toxicity and low bioavailability during bioremediation. The ecotoxicity values are a more valid indicator for evaluating the effectiveness of bioremediation techniques compared with only using the total petroleum hydrocarbon concentrations. Among all of the potential indicators that could be used to evaluate the effectiveness of bioremediation techniques, soil enzyme activities, phytotoxicity (inhibition of plant height, shoot weight and root fresh weight), malonaldehyde content, superoxide dismutase activity and luminescence of P. phosphoreum were the most sensitive.

  14. Polishing of Anaerobic Secondary Effluent and Symbiotic Bioremediation of Raw Municipal Wastewater by Chlorella Vulgaris

    KAUST Repository

    Cheng, Tuoyuan

    2016-05-01

    To assess polishing of anaerobic secondary effluent and symbiotic bioremediation of primary effluent by microalgae, bench scale bubbling column reactors were operated in batch modes to test nutrients removal capacity and associated factors. Chemical oxygen demand (COD) together with oil and grease in terms of hexane extractable material (HEM) in the reactors were measured after batch cultivation tests of Chlorella Vulgaris, indicating the releasing algal metabolites were oleaginous (dissolved HEM up to 8.470 mg/L) and might hazard effluent quality. Ultrafiltration adopted as solid-liquid separation step was studied via critical flux and liquid chromatography-organic carbon detection (LC-OCD) analysis. Although nutrients removal was dominated by algal assimilation, nitrogen removal (99.6% maximum) was affected by generation time (2.49 days minimum) instead of specific nitrogen removal rate (sN, 20.72% maximum), while phosphorus removal (49.83% maximum) was related to both generation time and specific phosphorus removal rate (sP, 1.50% maximum). COD increase was affected by cell concentration (370.90 mg/L maximum), specific COD change rate (sCOD, 0.87 maximum) and shading effect. sCOD results implied algal metabolic pathway shift under nutrients stress, generally from lipid accumulation to starch accumulation when phosphorus lower than 5 mg/L, while HEM for batches with initial nitrogen of 10 mg/L implied this threshold around 8 mg/L. HEM and COD results implied algal metabolic pathway shift under nutrients stress. Anaerobic membrane bioreactor effluent polishing showed similar results to synthetic anaerobic secondary effluent with slight inhibition while 4 symbiotic bioremediation of raw municipal wastewater with microalgae and activated sludge showed competition for ammonium together with precipitation or microalgal luxury uptake of phosphorus. Critical flux was governed by algal cell concentration for ultrafiltration membrane with pore size of 30 nm, while

  15. Algae as an electron donor promoting sulfate reduction for the bioremediation of acid rock drainage.

    Science.gov (United States)

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, Jim A

    2016-11-05

    This study assessed bioremediation of acid rock drainage in simulated permeable reactive barriers (PRB) using algae, Chlorella sorokiniana, as the sole electron donor for sulfate-reducing bacteria. Lipid extracted algae (LEA), the residues of biodiesel production, were compared with whole cell algae (WCA) as an electron donor to promote sulfate-reducing activity. Inoculated columns containing anaerobic granular sludge were fed a synthetic medium containing H2SO4 and Cu(2+). Sulfate, sulfide, Cu(2+) and pH were monitored throughout the experiment of 123d. Cu recovered in the column packing at the end of the experiment was evaluated using sequential extraction. Both WCA and LEA promoted 80% of sulfate removal (12.7mg SO4(2-) d(-1)) enabling near complete Cu removal (>99.5%) and alkalinity generation raising the effluent pH to 6.5. No noteworthy sulfate reduction, alkalinity formation and Cu(2+) removal were observed in the endogenous control. In algae amended-columns, Cu(2+) was precipitated with biogenic H2S produced by sulfate reduction. Formation of CuS was evidenced by sequential extraction and X-ray diffraction. LEA and WCA provided similar levels of electron donor based on the COD balance. The results demonstrate an innovative passive remediation system using residual algae biomass from the biodiesel industry.

  16. An in silico [correction of insilico] approach to bioremediation: laccase as a case study.

    Science.gov (United States)

    Suresh, Panneer Selvam; Kumar, Anil; Kumar, Rita; Singh, Ved Pal

    2008-01-01

    Laccase (E.C. 1.10.3.2) is one of the well-studied enzymes used for bioremediation of xenobiotics such as phenols, anilines, etc. Its broad substrate specificity offers a wide opportunity for screening pollutants in order to predict potential targets for degradation. Present study utilizes protein-ligand docking as a tool to achieve the said. For virtual screening, a set of pollutants were selected from five different industries from EPA. X-ray crystal structures of laccase enzymes were taken from the Brookhaven Protein Data Bank (PDB). Two-dimensional structures of pollutants were downloaded from the NCBI Pubchem, which were further converted into three-dimensional structures using CORINA. Protein-ligand docking was carried out using GOLD. Nearly 30 and 17% of the selected datasets showed the best average GOLD fitness score for fungal and bacterial laccase enzyme respectively, suggesting thereby that laccase might be able to oxidize these pollutants. Moreover, in few cases like anthracene, phenanthrene, etc., there is experimental data to support this hypothesis. Similar kind of work would be helpful to find putative pollutants for other biodegradative enzymes.

  17. Arsenic accumulating bacteria isolated from soil for possible application in bioremediation.

    Science.gov (United States)

    Majumder, Aparajita; Ghosh, Sagarmoy; Saha, Niharendu; Kole, S C; Sarkar, Supradip

    2013-09-01

    Twenty six arsenic (As) resistant bacterial strains were isolated from As contaminated paddy soil of West Bengal, India. Among them, 10 isolates exhibited higher As resistance capacity and could grow in concentration of 12000 mg I-1 of arsenate (AsV) and 2000 mg l-1 of arsenite (Aslll) in growing medium. Maximum growth was observed at 1000 mg I-1and 100 mg I-1 in case of AsV and Asll respectively. Results of incubation study carried out in basal salt minimal media (BSMY) containing 25 mg l-1 of AsV and Aslll separately showed that the isolates could accumulate 1.03 - 6.41 mg I-1 of AsV and 2.0 - 7.6 mg l-1 of Aslll from the media. The bacterial isolate AGH-21 showed highest As accumulating capacity both for AsV (25.64%) and Aslll (30.4%) under laboratory conditions. The isolates AGH-21 (NCBI accession no: HQ834295) showed highest sequence similarity (98%) with Bacillus sp. and could be used as a potential bioremediator in future to combat with arsenic toxicity.

  18. Bioremediation of chlorinated pesticide-contaminated soil using anaerobic sludges and surfactant addition.

    Science.gov (United States)

    Baczynski, Tomasz P; Pleissner, Daniel

    2010-01-01

    Methanogenic granular sludge and wastewater fermented sludge were used as inocula for batch tests of anaerobic bioremediation of chlorinated pesticide contaminated soil. Results obtained for both types of biomass were similar: 80 to over 90% of gamma -hexachlorocyclohexane (gamma-HCH), 1,1,1-trichloro-2,2-bis-(4-methoxyphenyl)ethane (methoxychlor) and 1,1,1-trichloro-2,2-bis-(4-chlorophenyl)ethane (DDT) removed in 4-6 weeks. Residual fractions of these pesticides persisted till the end of the 16-week experiment. DDT was degraded through 1,1-dichloro-2,2-bis-(4-chlorophenyl)ethane (DDD). Accumulation of this product corresponded stoichiometrically only to 34-53% of removed DDT, supposedly due to its further transformations, finally resulting in formation of detected 4,4'-dichlorobenzophenone (DBP). Addition of 0.5 mM Tween 80 nonionic surfactant resulted in about a twofold decrease of gamma -HCH and methoxychlor residual concentrations, as well as considerably lower DDD accumulation (7-29%) and higher DBP production. However, 1.25 mM dose of this surfactant applied together with granular sludge brought DDD levels back to that observed for treatments with the sludge alone, also impairing DBP formation.

  19. Isolation, identification and characterization of indigenous fungi for bioremediation of hexavalent chromium, nickel and cobalt

    Science.gov (United States)

    Hernahadini, Nelis; Suhandono, Sony; Choesin, Devi N.; Chaerun, Siti K.; Kadarusman, Ade

    2014-03-01

    Waste from nickel mining of Sorowako in South Sulawesi contains hexavalent chromium, nickel and cobalt metals in high concentration and may have a negative impact to the environment. Common waste treatment systems such as chemical treatment using a reducing reagent may still have a negative impact. Bioremediation using fungi or bacteria becomes more popular because it is an environmentally friendly alternative. The purposes of this study are to isolate and identify indigenous fungi that are resistant to heavy metals (hexavalent chromium, nickel, and cobalt) and are capable of reducing the concentration of metals in mining wastes. Ten fungal isolates were successfully isolated from the soils and pond sediments in the area of nickel mining in Sorowako. Selection of superior isolate was carried out by growing all the isolates on PDA medium, which contained all of the three metals. One superior isolate was identified to be able to grow on medium with concentrations of 6400 ppm hexavalent chromium, 200 ppm nickel and 50 ppm cobalt. Molecular identification and phylogenetic studies of the isolate using fungal PCR primers developed to amplify the ITS (internal transcribed spacer) region showed that the isolate sequence was very close to Trichoderma atroviride with 99.8% similarity. Optimum incubation time for the uptake of hexavalent chromium was 3 days, nickel and cobalt was 5 days, respectively, with an optimum pH of 4.

  20. Compost as a source of microbial isolates for the bioremediation of heavy metals: in vitro selection.

    Science.gov (United States)

    Vargas-García, María del Carmen; López, María José; Suárez-Estrella, Francisca; Moreno, Joaquín

    2012-08-01

    Heavy metal pollution has become a major environmental concern nowadays and the bioremediation of polluted habitats is an increasingly popular strategy due to both its efficiency and safety. A screening and selection protocol based on different composting processes was designed in order to isolate heavy metal-resistant microorganisms. A collection of 51 microorganisms was obtained and most of them showed the capability to tolerate heavy metals in multi-polluted aqueous systems (Cd(II), Cr(VI), Ni, Pb, Zn(II)), as well as to remove them. The highest detoxification ratios were observed for Pb. Some of the isolates detoxifying more than a 90% of this metal, while the other metals were removed in a range between 20% and 60%. The best isolates (Graphium putredinis, Fusarium solani, Fusarium sp. and Penicillium chrysogenum) were further assayed in order to determine the predominant removal mechanism and the potential use of their dead biomass as a biosorbent. Intracellular accumulation was the prevalent mechanism for most isolates and metals, with the exception of Ni. In this case, the proportion removed by extracellular adsorption was similar or even higher than that removed by intracellular accumulation. Thus, the efficiency of living cells was higher than that of dead biomass except in the case of Ni.

  1. Estimating similarity of XML Schemas using path similarity measure

    Directory of Open Access Journals (Sweden)

    Veena Trivedi

    2012-07-01

    Full Text Available In this paper, an attempt has been made to develop an algorithm which estimates the similarity for XML Schemas using multiple similarity measures. For performing the task, the XML Schema element information has been represented in the form of string and four different similarity measure approaches have been employed. To further improve the similarity measure, an overall similarity measure has also been calculated. The approach used in this paper is a distinguished one, as it calculates the similarity between two XML schemas using four approaches and gives an integrated values for the similarity measure. Keywords-componen

  2. Bioremediation of Metals and Radionuclides: What It Is and How It Works (2nd Edition)

    Energy Technology Data Exchange (ETDEWEB)

    Palmisano, Anna; Hazen, Terry

    2003-09-30

    This primer is intended for people interested in environmental problems of the U.S. Department of Energy (DOE) and in their potential solutions. It will specifically look at some of the more hazardous metal and radionuclide contaminants found on DOE lands and at the possibilities for using bioremediation technology to clean up these contaminants. The second edition of the primer incorporates recent findings by researchers in DOE's Natural and Accelerated Bioremediation Research (NABIR) Program. Bioremediation is a technology that can be used to reduce, eliminate, or contain hazardous waste. Over the past two decades, it has become widely accepted that microorganisms, and to a lesser extent plants, can transform and degrade many types of contaminants. These transformation and degradation processes vary, depending on the physical-chemical environment, microbial communities, and nature of the contaminant. This technology includes intrinsic bioremediation, which relies on naturally occurring processes, and accelerated bioremediation, which enhances microbial degradation or transformation through the addition of nutrients (biostimulation) or inoculation with microorganisms (bioaugmentation). Over the past few years, interest in bioremediation has increased. It has become clear that many organic contaminants such as hydrocarbon fuels can be degraded to relatively harmless products such as CO{sub 2} (the end result of the degradation process). Waste water managers and scientists have also found that microorganisms can interact with metals and convert them from one chemical form to another. Laboratory tests and ex situ bioremediation applications have shown that microorganisms can change the valence, or oxidation state, of some heavy metals (e.g., chromium and mercury) and radionuclides (e.g., uranium) by using them as electron acceptors. In some cases, the solubility of the altered species decreases and the contaminant is immobilized in situ, i.e., precipitated into

  3. Assessment of microbial community changes and limiting factors during bioremediation of hydrocarbon-polluted soil with new miniaturized physiological methods

    OpenAIRE

    Kaufmann, Karin; Holliger, Hans Christof

    2005-01-01

    Due to human activities, organic pollutants are spilled to the environment where they threaten public health, often as contaminants of soil or groundwater. Living organisms are able to transform or mineralize many organic pollutants, and bioremediation techniques have been developed to remove pollutants from a contaminated site. However, fast and easy methods to document both the efficacy of bioremediation and the changes in soil microbial communities during bioremediation are not well develo...

  4. A cost effective bioremediation strategy using low technology resources for reclamation of dry land hydrocarbon contamination: A case study

    Energy Technology Data Exchange (ETDEWEB)

    Robb, A.J. III; Hoggatt, P.R.

    1995-12-01

    Hydrocarbon containing soil was bioremediated at a combination wastewater and slop oil skim evaporation pond utilizing cost effective low technology resources. Fluids and sludge from the football field-sized pond were extraction procedure toxicity and purgeable organics tested, and total petroleum hydrocarbon (TPH) concentrations determined. An impact risk analysis was performed, and a corrective action plan developed and implemented. The three year project was closely coordinated with the Kansas Corporation Commission (KCC) and the Kansas Department of Health and Environment (KDHE) who established the closure level. The impacted soils at the pond were completely excavated and closure was immediately granted by KDHE for the excavated area. The 24,000 cubic yards of excavated soil were then surface spread on adjacent Mobil property. A nutrient and microbial base was applied to bioaugment the soil. The preapplication land surface and the subsequently land farmed soil was periodically disced and chiseled. A job safety plan including industrial hygiene measures to eliminate workforce exposure was developed and implemented. The final remediation cost analysis amounts to $1.48 per cubic yard compared to the $30 to $150 per cubic yard industry o estimates for similar projects. Several factors were critical in ailing costs to remain so low: (1) assessment and implementation by local in-house staff, (2) conservative remedial action plan and sampling strategy; (3) local contractors; (4) locally available soil amendment; and (5) effective regulatory coordination. The methods described can be used to cost effectively characterize and bioremediate other sites where hydrocarbon-impacted soils exist in similar dry-land environments.

  5. Air-dust-borne associations of phototrophic and hydrocarbon-utilizing microorganisms: promising consortia in volatile hydrocarbon bioremediation.

    Science.gov (United States)

    Al-Bader, Dhia; Eliyas, Mohamed; Rayan, Rihab; Radwan, Samir

    2012-11-01

    Aquatic and terrestrial associations of phototrophic and heterotrophic microorganisms active in hydrocarbon bioremediation have been described earlier. The question arises: do similar consortia also occur in the atmosphere? Dust samples at the height of 15 m were collected from Kuwait City air, and analyzed microbiologically for phototrophic and heterotrophic hydrocarbon-utilizing microorganisms, which were subsequently characterized according to their 16S rRNA gene sequences. The hydrocarbon utilization potential of the heterotrophs alone, and in association with the phototrophic partners, was measured quantitatively. The chlorophyte Gloeotila sp. and the two cyanobacteria Nostoc commune and Leptolyngbya thermalis were found associated with dust, and (for comparison) the cynobacteria Leptolyngbya sp. and Acaryochloris sp. were isolated from coastal water. All phototrophic cultures harbored oil vapor-utilizing bacteria in the magnitude of 10(5) g(-1). Each phototrophic culture had its unique oil-utilizing bacteria; however, the bacterial composition in Leptolyngbya cultures from air and water was similar. The hydrocarbon-utilizing bacteria were affiliated with Acinetobacter sp., Aeromonas caviae, Alcanivorax jadensis, Bacillus asahii, Bacillus pumilus, Marinobacter aquaeolei, Paenibacillus sp., and Stenotrophomonas maltophilia. The nonaxenic cultures, when used as inocula in batch cultures, attenuated crude oil in light and dark, and in the presence of antibiotics and absence of nitrogenous compounds. Aqueous and diethyl ether extracts from the phototrophic cultures enhanced the growth of the pertinent oil-utilizing bacteria in batch cultures, with oil vapor as a sole carbon source. It was concluded that the airborne microbial associations may be effective in bioremediating atmospheric hydrocarbon pollutants in situ. Like the aquatic and terrestrial habitats, the atmosphere contains dust-borne associations of phototrophic and heterotrophic hydrocarbon

  6. Mining Object Similarity for Predicting Next Locations

    Institute of Scientific and Technical Information of China (English)

    Meng Chen; Xiaohui Yu; Yang Liu

    2016-01-01

    Next location prediction is of great importance for many location-based applications. With the virtue of solid theoretical foundations, Markov-based approaches have gained success along this direction. In this paper, we seek to enhance the prediction performance by understanding the similarity between objects. In particular, we propose a novel method, called weighted Markov model (weighted-MM), which exploits both the sequence of just-passed locations and the object similarity in mining the mobility patterns. To this end, we first train a Markov model for each object with its own trajectory records, and then quantify the similarities between different objects from two aspects: spatial locality similarity and trajectory similarity. Finally, we incorporate the object similarity into the Markov model by considering the similarity as the weight of the probability of reaching each possible next location, and return the top-rankings as results. We have conducted extensive experiments on a real dataset, and the results demonstrate significant improvements in prediction accuracy over existing solutions.

  7. SEAL: Spatio-Textual Similarity Search

    CERN Document Server

    Fan, Ju; Zhou, Lizhu; Chen, Shanshan; Hu, Jun

    2012-01-01

    Location-based services (LBS) have become more and more ubiquitous recently. Existing methods focus on finding relevant points-of-interest (POIs) based on users' locations and query keywords. Nowadays, modern LBS applications generate a new kind of spatio-textual data, regions-of-interest (ROIs), containing region-based spatial information and textual description, e.g., mobile user profiles with active regions and interest tags. To satisfy search requirements on ROIs, we study a new research problem, called spatio-textual similarity search: Given a set of ROIs and a query ROI, we find the similar ROIs by considering spatial overlap and textual similarity. Spatio-textual similarity search has many important applications, e.g., social marketing in location-aware social networks. It calls for an efficient search method to support large scales of spatio-textual data in LBS systems. To this end, we introduce a filter-and-verification framework to compute the answers. In the filter step, we generate signatures for ...

  8. Response of Archaeal communities in beach sediments to spilled oil and bioremediation.

    Science.gov (United States)

    Röling, Wilfred F M; de Brito Couto, Ivana R; Swannell, Richard P J; Head, Ian M

    2004-05-01

    While the contribution of Bacteria to bioremediation of oil-contaminated shorelines is well established, the response of Archaea to spilled oil and bioremediation treatments is unknown. The relationship between archaeal community structure and oil spill bioremediation was examined in laboratory microcosms and in a bioremediation field trial. 16S rRNA gene-based PCR and denaturing gradient gel analysis revealed that the archaeal community in oil-free laboratory microcosms was stable for 26 days. In contrast, in oil-polluted microcosms a dramatic decrease in the ability to detect Archaea was observed, and it was not possible to amplify fragments of archaeal 16S rRNA genes from samples taken from microcosms treated with oil. This was the case irrespective of whether a bioremediation treatment (addition of inorganic nutrients) was applied. Since rapid oil biodegradation occurred in nutrient-treated microcosms, we concluded that Archaea are unlikely to play a role in oil degradation in beach ecosystems. A clear-cut relationship between the presence of oil and the absence of Archaea was not apparent in the field experiment. This may have been related to continuous inoculation of beach sediments in the field with Archaea from seawater or invertebrates and shows that the reestablishment of Archaea following bioremediation cannot be used as a determinant of ecosystem recovery following bioremediation. Comparative 16S rRNA sequence analysis showed that the majority of the Archaea detected (94%) belonged to a novel, distinct cluster of group II uncultured Euryarchaeota, which exhibited less than 87% identity to previously described sequences. A minor contribution of group I uncultured Crenarchaeota was observed.

  9. In Situ Bioremediation of Chlorinated Ethenes in Hydraulically-Tight Sediments: Challenges and Limitations

    Science.gov (United States)

    Zhang, M.; Yoshikawa, M.; Takeuchi, M.; Komai, T.

    2011-12-01

    Chlorinated ethenes, like perchloroethene (PCE) and trichloroethene (TCE), have been widely used by many industries, especially in developed countries like Japan. Because of their wide applications, lack of proper regulation, poor handing, storage and disposal practices in the past, chlorinated ethenes have become a type of the most prevalent contaminants for soils and groundwater pollution. For the sake of their degradability, bioremediation has been considered as a potentially cost-effective and environmentally friendly approach for cleanup of chlorinated ethenes in situ. In this presentation, we briefly overview the status of soil and groundwater pollution, the recent amendment of the Soil Contamination Countermeasures Act in Japan, comparison between the bioremediation and other techniques like pump and treat, and the mechanisms of reductive dechlorination, direct oxidation and co-metabolism of chlorinated ethenes. We then introduce and discuss some recent challenges and advancements in in-situ bioremediation including technologies for accelerating bio-degradation of chlorinated ethenes, technologies for assessing diffusive properties of dissolved hydrogen in hydraulically-tight soil samples, and combination of bioremediation with other techniques like electro-kinetic approach. Limiting factors that may cause incomplete remediation and/or ineffectiveness of bioremediation are examined from biochemical, geochemical and hydro-geological aspects. This study reconfirmed and illustrated that: 1) The key factor for an effective bioremediation is how to disperse a proper accelerating agent throughout the polluted strata, 2) The effective diffusion coefficient of dissolved hydrogen in geologic media is relatively big and is almost independent on their permeability, and 3) To effectively design and perform an accelerated bioremediation, a combination of natural migration with pressurized injection and/or other approaches, like electro-migration, for stimulating mass

  10. INFLUENCE OF TIDE AND WAVES ON WASHOUT OF DISSOLVED NUTRIENTS FROM THE BIOREMEDIATION ZONE OF A COARSE-SAND BEACH: APPLICATION IN OIL-SPILL BIOREMEDIATION

    Science.gov (United States)

    Successful bioremediation of oil-contaminated beaches requires maintenance of a sufficient quantity of growth-limiting nutrients in contact with the oiled beach materials. A conservative tracer study was conducted on a moderate-energy, sandy beach on Delaware Bay to estimate the...

  11. Similarity measures for protein ensembles

    DEFF Research Database (Denmark)

    Lindorff-Larsen, Kresten; Ferkinghoff-Borg, Jesper

    2009-01-01

    Analyses of similarities and changes in protein conformation can provide important information regarding protein function and evolution. Many scores, including the commonly used root mean square deviation, have therefore been developed to quantify the similarities of different protein conformatio...

  12. Spatial cognition

    Science.gov (United States)

    Kaiser, Mary Kister; Remington, Roger

    1988-01-01

    Spatial cognition is the ability to reason about geometric relationships in the real (or a metaphorical) world based on one or more internal representations of those relationships. The study of spatial cognition is concerned with the representation of spatial knowledge, and our ability to manipulate these representations to solve spatial problems. Spatial cognition is utilized most critically when direct perceptual cues are absent or impoverished. Examples are provided of how human spatial cognitive abilities impact on three areas of space station operator performance: orientation, path planning, and data base management. A videotape provides demonstrations of relevant phenomena (e.g., the importance of orientation for recognition of complex, configural forms). The presentation is represented by abstract and overhead visuals only.

  13. Functional Similarity and Interpersonal Attraction.

    Science.gov (United States)

    Neimeyer, Greg J.; Neimeyer, Robert A.

    1981-01-01

    Students participated in dyadic disclosure exercises over a five-week period. Results indicated members of high functional similarity dyads evidenced greater attraction to one another than did members of low functional similarity dyads. "Friendship" pairs of male undergraduates displayed greater functional similarity than did "nominal" pairs from…

  14. Investigation of the bioremediation potential of aerobic zymogenous microorganisms in soil for crude oil biodegradation

    Directory of Open Access Journals (Sweden)

    TATJANA ŠOLEVIĆ

    2011-03-01

    Full Text Available The bioremediation potential of the aerobic zymogenous microorganisms in soil (Danube alluvium, Pančevo, Serbia for crude oil biodegradation was investigated. A mixture of paraffinic types of oils was used as the substrate. The laboratory experiment of the simulated oil biodegradation lasted 15, 30, 45, 60 and 75 days. In parallel, an experiment with a control sample was conducted. Extracts were isolated from the samples with chloroform in a separation funnel. From these extracts, the hydrocarbons were isolated by column chromatography and analyzed by gas chromatography–mass spectrometry (GC–MS. n-Alkanes, isoprenoids, phenanthrene and its derivatives with one and two methyl groups were quantitatively analyzed. The ability and efficiency of zymogenous microorganisms in soil for crude oil bioremediation was assessed by comparison between the composition of samples which were exposed to the microorganisms and the control sample. The investigated microorganisms showed the highest bioremediation potential in the biodegradation of n-alkanes and isoprenoids. A considerably high bioremediation potential was confirmed in the biodegradation of phenanthrene and methyl phenanthrenes. Low bioremediation potential of these microorganisms was proven in the case of polycyclic alkanes of the sterane and triterpane types and dimethyl phenanthrenes.

  15. Effectiveness of bioremediation for the Prestige fuel spill : a summary of case studies

    Energy Technology Data Exchange (ETDEWEB)

    Gallego, J.R. [Oviedo Univ., Asturias (Spain); Gonzalez-Rojas, E.; Pelaez, A.I.; Sanchez, J [Oviedo Univ., Asturias (Spain). Inst. de Biotecnologia de Asturias; Garcia-Martinez, M.J.; Llamas, J.F. [Univ. Polictenica de Madrid, Madrid (Spain). Laboratorio de Estratigrafia Biomolecular

    2006-07-01

    This paper described novel bioremediation strategies used to remediate coastal areas in Spain impacted by the Prestige fuel oil spill in 2002. The bioremediation techniques were applied after hot pressurized water washing was used to remove hydrocarbons adhering to shorelines and rocks. Bioremediation strategies included monitored natural attenuation as well as accelerating biodegradation by stimulating indigenous populations through the addition of exogenous microbial populations. The sites selected for bioremediation were rocky shorelines of heterogenous granitic sediments with grain sizes ranging from sands to huge boulders; limestone-sandstone pebbles and cobbles; and fuel-coated limestone cliffs. Total surface area covered by the fuel was determined through the use of image analysis calculations. A statistical measurement of the fuel layer thickness was calculated by averaging the weights of multiple-fuel sampling increments. Bioremediation products included the use of oleophilic fertilizers; a biodegradable surfactant; and a microbial seeding agent. Determinations of saturate, aromatic, resins, and asphaltene (SARA) were performed using maltenes extraction and liquid chromatography. Microbial plating and selective enrichment with fuel as the sole carbon source were used to monitor the evolution of microbial populations in a variety of experiments. It was concluded that the biostimulation technique enhanced the efficiency of the in situ oleophilic fertilizers. 17 refs., 2 tabs., 6 figs.

  16. Key Factors Controlling the Applicability and Efficiency of Bioremediation of Chlorinated Ethenes In Situ

    Science.gov (United States)

    Zhang, M.; Yoshikawa, M.; Takeuchi, M.; Komai, T.

    2012-12-01

    Bioremediation has been considered as one of environmentally friendly and cost effective approaches for cleaning up the sites polluted by organic contaminants, such as chlorinated ethenes. Although bioremediation, in its widest sense, is not new, and many researches have been performed on bioremediation of different kinds of pollutants, an effective design and implication of in situ bioremediation still remains a challenging problem because of the complexity. Many factors may affect the applicability and efficiency of bioremediation of chlorinated ethenes in situ, which include the type and concentration of contaminants, biological, geological and hydro-geological conditions of the site, physical and chemical characteristics of groundwater and soils to be treated, as well as the constraints in engineering. In this presentation, an overview together with a detailed discussion on each factor will be provided. The influences of individual factors are discussed using the data obtained or cited from different sites and experiments, and thus under different environmental conditions. The results of this study illustrated that 1) the establishment of microbial consortium is of crucial importance for a complete degradation of chlorinated ethenes, 2) in situ control of favorable conditions for increasing microbial activities for bio-degradation through a designed pathway is the key to success, 3) the focus of a successful remediation system is to design an effective delivery process that is capable of producing adequate amendment mixing of contaminant-degrading bacteria, appropriate concentrations of electron acceptors, electron donors, and microbial nutrients in the subsurface treatment area.

  17. Distribution of hydrocarbon-degrading bacteria in the soil environment and their contribution to bioremediation.

    Science.gov (United States)

    Fukuhara, Yuki; Horii, Sachie; Matsuno, Toshihide; Matsumiya, Yoshiki; Mukai, Masaki; Kubo, Motoki

    2013-05-01

    A real-time PCR quantification method for indigenous hydrocarbon-degrading bacteria (HDB) carrying the alkB gene in the soil environment was developed to investigate their distribution in soil. The detection limit of indigenous HDB by the method was 1 × 10(6) cells/g-soil. The indigenous HDB were widely distributed throughout the soil environment and ranged from 3.7 × 10(7) to 5.0 × 10(8) cells/g-soil, and the ratio to total bacteria was 0.1-4.3 %. The dynamics of total bacteria, indigenous HDB, and Rhodococcus erythropolis NDKK6 (carrying alkB R2) during bioremediation were analyzed. During bioremediation with an inorganic nutrient treatment, the numbers of these bacteria were slightly increased. The numbers of HDB (both indigenous bacteria and strain NDKK6) were gradually decreased from the middle stage of bioremediation. Meanwhile, the numbers of these bacteria were highly increased and were maintained during bioremediation with an organic nutrient. The organic treatment led to activation of not only the soil bacteria but also the HDB, so an efficient bioremediation was carried out.

  18. Electrokinetic-enhanced bioremediation of organic contaminants: a review of processes and environmental applications.

    Science.gov (United States)

    Gill, R T; Harbottle, M J; Smith, J W N; Thornton, S F

    2014-07-01

    There is current interest in finding sustainable remediation technologies for the removal of contaminants from soil and groundwater. This review focuses on the combination of electrokinetics, the use of an electric potential to move organic and inorganic compounds, or charged particles/organisms in the subsurface independent of hydraulic conductivity; and bioremediation, the destruction of organic contaminants or attenuation of inorganic compounds by the activity of microorganisms in situ or ex situ. The objective of the review is to examine the state of knowledge on electrokinetic bioremediation and critically evaluate factors which affect the up-scaling of laboratory and bench-scale research to field-scale application. It discusses the mechanisms of electrokinetic bioremediation in the subsurface environment at different micro and macroscales, the influence of environmental processes on electrokinetic phenomena and the design options available for application to the field scale. The review also presents results from a modelling exercise to illustrate the effectiveness of electrokinetics on the supply electron acceptors to a plume scale scenario where these are limiting. Current research needs include analysis of electrokinetic bioremediation in more representative environmental settings, such as those in physically heterogeneous systems in order to gain a greater understanding of the controlling mechanisms on both electrokinetics and bioremediation in those scenarios.

  19. Change of isoprenoids, steranes and terpanes during ex situ bioremediation of mazut on industrial level

    Directory of Open Access Journals (Sweden)

    Beškoski Vladimir P.

    2010-01-01

    Full Text Available The paper presents results of the ex situ bioremediation of soil contaminated by mazut (heavy residual fuel oil in the field scale (600 m3. A treatment-bed (thickness 0.4 m consisted of mechanically mixed mazut-contaminated soil, softwood sawdust as the additional carbon source and crude river sand, as bulking and porosity increasing material. The inoculation/reinoculation was conducted periodically using a biomass of a consortium of zymogenous microorganisms isolated from the bioremediation substrate. The biostimulation was performed through addition of nutritious substances (N, P and K. The aeration was improved by systematic mixing of the bioremediation system. After 50 days, the number of hydrocarbon degraders increased 100 times. Based on the changes in the group composition, the average biodegradation rate during bioremediation was 24 mg/kg/day for the aliphatic fraction, 6 mg/kg/day for the aromatic fraction, and 3 mg/kg/day for the nitrogen-sulphuroxygen compounds (NSO-asphaltene fraction. In the saturated hydrocarbon fraction, gas chromatography-mass spectrometry (GC-MS in the single ion-monitoring mode (SIM was applied to analyse isoprenoids pristane and phytane and polycyclic molecules of sterane and triterpane type. Biodegradation occurred during the bioremediation process, as well as reduction of relative quantities of isoprenoids, steranes, tri- and tetracyclic terpanes and pentacyclic terpanes of hopane type.

  20. PROSPECTIVE IN-SILCO APPROACH IN BIOREMEDIATION OF PETROLEUM HYDROCARBON: SUCCESS SO FAR

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    Mohammad Nadeem Khan

    2013-06-01

    Full Text Available Bioremediation has the potential to reduce contaminated environment inexpensively yet effectively. But, the lack of information about the factors controlling the growth and metabolism in microorganisms in polluted environment often limits its implementation. However rapid advances in the understanding of bioremediation are on the horizon. With advances in biotechnology, bioremediation has become one of the most rapidly developing fields of environmental restoration, utilizing microorganisms to reduce the concentration and toxicity of various chemical pollutants, such as petroleum hydrocarbons. In this mini-review, the current state of the field is described and the role of synthetic biology in biotechnology in short and medium term is discussed. A number of bioremediation strategies have been developed to treat contaminated wastes and sites. Selecting the most appropriate strategy to treat a specific site can be guided by considering three basic principles: the amenability of the pollutant to biological transformation to less toxic products, the bioavailability of the contaminant to microorganisms and the opportunity for bioprocess optimization. By the recent advances on in-silico dimensions of bioremediation, it seems that the synthetic biology software will soon drive the wet-lab implementation at molecular level.

  1. Monitoring genetic and metabolic potential for in situ bioremediation: Mass spectrometry. 1997 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Buchanan, M.V.; Hurst, G.B.; Britt, P.F.; McLuckey, S.A.; Doktycz, M.J.

    1997-09-01

    'A number of US Department of Energy (DOE) sites are contaminated with mixtures of dense non-aqueous phase liquids (DNAPLs) such as carbon tetrachloride, chloroform,. perchloroethylene, and trichloroethylene. At many of these sites, in situ microbial bioremediation is an attractive strategy for cleanup because it has the potential to degrade DNAPLs in situ without producing toxic byproducts. A rapid screening method to determine the broad range metabolic and genetic potential for contaminant degradation would greatly reduce the cost and time involved in assessment for in situ bioremediation as well as for monitoring ongoing bioremediation treatment. In this project, the ORNL Organic Mass Spectrometry (OMS) group is developing mass-spectrometry-based methods to screen for the genetic and metabolic potential for assessment and monitoring of in situ bioremediation of DNAPLs. In close collaboration, Professor Mary Lidstrom''s group at the University of Washington is identifying short DNA sequences related to microbial processes involved in the biodegradation of pollutants. This work will lay the foundation for development of a field-portable mass-spectrometry-based technique for rapid assessment and monitoring of bioremediation processes on site.'

  2. Sensitivity of geological, geochemical and hydrologic parameters in complex reactive transport systems for in-situ uranium bioremediation

    Science.gov (United States)

    Yang, G.; Maher, K.; Caers, J.

    2015-12-01

    Groundwater contamination associated with remediated uranium mill tailings is a challenging environmental problem, particularly within the Colorado River Basin. To examine the effectiveness of in-situ bioremediation of U(VI), acetate injection has been proposed and tested at the Rifle pilot site. There have been several geologic modeling and simulated contaminant transport investigations, to evaluate the potential outcomes of the process and identify crucial factors for successful uranium reduction. Ultimately, findings from these studies would contribute to accurate predictions of the efficacy of uranium reduction. However, all these previous studies have considered limited model complexities, either because of the concern that data is too sparse to resolve such complex systems or because some parameters are assumed to be less important. Such simplified initial modeling, however, limits the predictive power of the model. Moreover, previous studies have not yet focused on spatial heterogeneity of various modeling components and its impact on the spatial distribution of the immobilized uranium (U(IV)). In this study, we study the impact of uncertainty on 21 parameters on model responses by means of recently developed distance-based global sensitivity analysis (DGSA), to study the main effects and interactions of parameters of various types. The 21 parameters include, for example, spatial variability of initial uranium concentration, mean hydraulic conductivity, and variogram structures of hydraulic conductivity. DGSA allows for studying multi-variate model responses based on spatial and non-spatial model parameters. When calculating the distances between model responses, in addition to the overall uranium reduction efficacy, we also considered the spatial profiles of the immobilized uranium concentration as target response. Results show that the mean hydraulic conductivity and the mineral reaction rate are the two most sensitive parameters with regard to the overall

  3. Enhanced bioremediation process: A case study of effectiveness on PAH contamination in soils at a former wood-treating site

    Energy Technology Data Exchange (ETDEWEB)

    Mills, W.F. [Miltech Environmental, Inc., Tucker, GA (United States); Matens, B.L. [Dames and Moore, Baton Rouge, LA (United States); Buchalter, D.S. [EMCON, Norcross, GA (United States); Montgomery, D.N. [Georgia Dept. of Transportation, Forest Park, GA (United States). Office of Materials and Research

    1997-12-31

    The Enhanced Bioremediation Process (EBP) technology is an exsitu biodegradation process that utilizes bacterial and fungal inoculants to effectively oxidize and bioremediate persistent hard to degrade organics in contaminated soils. The EBP fungal inoculants produce highly reactive extracellular peroxidase enzymes that can oxidize and degrade lignin, a complex, natural polymer composed of phenylpropane units that is resistant to decay. The lignin peroxidase enzymes are highly nonspecific because of their ability to oxidize the heterogenic lignin molecule, and are capable of degrading a wide variety of complex organic compounds. Because the chemical sub-structure of lignin (1,2-aryl diethers, alkyl sidechains and connected aryl systems) resembles that of many persistent organic compounds, the EBP inoculants are very effective in biodegrading similar hazardous organic pollutants in contaminated soils. As an inadvertent by-product of these biochemical processes, the EBP organisms reduce the organic constituents to a soluble form. In a soluble form, the indigenous organisms can further degrade the contaminants. The technology is applied in such a manner as to maximize the activity of the indigenous organisms by establishing optimum growth conditions. The efficacy of the EBP technology in degrading persistent environmental pollutants has been documented at both the bench scale and pilot demonstration levels. A recently completed field pilot demonstration was conducted at a creosote contaminated site. The demonstration entailed the treatment of approximately 700 tons of soil contaminated with PAH constituents. Laboratory analyses of pre and post-treated soils indicate that total average PAH concentrations in many samples were reduced by greater than 91 percent over a two month treatment period.

  4. Scale-up impacts on mass transfer and bioremediation of suspended naphthalene particles in bead mill bioreactors.

    Science.gov (United States)

    Wang, Yuching; Riess, Ryan; Nemati, Mehdi; Hill, Gordon; Headley, John

    2008-11-01

    Scale-up effects on mass transfer and bioremediation of suspended naphthalene particles have been studied in 20 and 58L bead mill bioreactors and compared to data generated earlier with a laboratory scaled bioreactor. The bead mill bioreactor performance with respect to naphthalene mass transfer rate was dependent on the size and loading of the inert particles, as well as the rotational speed of the roller apparatus. The optimum operating conditions were found to be 15mm glass beads at a loading of 50% (total volume of particles/working volume of bioreactor: v/v%) and a bioreactor rotational speed of 50rpm. The highest naphthalene mass transfer coefficients obtained in the large scale system under these optimum conditions (19.6 and 22.4h(-1) for 20 and 58L vessels, respectively) were higher than those determined previously in a 2.5L bead mill bioreactor (0.7h(-1)). The acute toxicity tests indicated that the bioreactor effluent was less toxic than the untreated naphthalene suspension. Biodegradation rates obtained in these large scale bead mill bioreactors under optimum conditions (36-37.4mgL(-1)h(-1)) were higher than those achieved in the control bioreactors of similar sizes (11.4 and 11.6mgL(-1)h(-1)) but were slower than those previously determined in a 2.5L bead mill bioreactor (59-61.5mgL(-1)h(-1)). The limitation of oxygen in the large scale systems and damage of the bacterial cells due to the crushing effects of the large beads are likely contributing factors in the lower observed biodegradation rates. The optimum conditions with respect to naphthalene mass transfer might not necessarily translate to optimum performance with regard to bioremediation.

  5. Bioremediation of the textile waste effluent by Chlorella vulgaris

    Directory of Open Access Journals (Sweden)

    Hala Yassin El-Kassas

    2014-01-01

    Full Text Available The microalgae biomass production from textile waste effluent is a possible solution for the environmental impact generated by the effluent discharge into water sources. The potential application of Chlorella vulgaris for bioremediation of textile waste effluent (WE was investigated using 22 Central Composite Design (CCD. This work addresses the adaptation of the microalgae C. vulgaris in textile waste effluent (WE and the study of the best dilution of the WE for maximum biomass production and for the removal of colour and Chemical Oxygen Demand (COD by this microalga. The cultivation of C. vulgaris, presented maximum cellular concentrations Cmax and maximum specific growth rates μmax in the wastewater concentration of 5.0% and 17.5%, respectively. The highest colour and COD removals occurred with 17.5% of textile waste effluent. The results of C. vulgaris culture in the textile waste effluent demonstrated the possibility of using this microalga for the colour and COD removal and for biomass production. There was a significant negative relationship between textile waste effluent concentration and Cmax at 0.05 level of significance. However, sodium bicarbonate concentration did not significantly influence the responses of Cmax and the removal of colour and COD.

  6. Bioremediation via in situ microbial degradation of organic pollutants.

    Science.gov (United States)

    Vogt, Carsten; Richnow, Hans Hermann

    2014-01-01

    Contamination of soil and natural waters by organic pollutants is a global problem. The major organic pollutants of point sources are mineral oil, fuel components, and chlorinated hydrocarbons. Research from the last two decades discovered that most of these compounds are biodegradable under anoxic conditions. This has led to the rise of bioremediation strategies based on the in situ biodegradation of pollutants. Monitored natural attenuation is a concept by which a contaminated site is remediated by natural biodegradation; to evaluate such processes, a combination of chemical and microbiological methods are usually used. Compound specific stable isotope analysis emerged as a key method for detecting and quantifying in situ biodegradation. Natural attenuation processes can be initiated or accelerated by manipulating the environmental conditions to become favorable for indigenous pollutant degrading microbial communities or by adding externally breeded specific pollutant degrading microorganisms; these techniques are referred to as enhanced natural attenuation. Xenobiotic micropollutants, such as pesticides or pharmaceuticals, contaminate diffusively large areas in low concentrations; the biodegradation pattern of such contaminations are not yet understood.

  7. Bioremediation of coal contaminated soil under sulfate-reducing condition

    Energy Technology Data Exchange (ETDEWEB)

    Kuwano, Y.; Shimizu, Y. [Kyoto University, Shiga (Japan)

    2006-01-15

    The objective of this study was to investigate the biodegradation of coal-derived hydrocarbons, especially high molecular weight (HMW) components, under anaerobic conditions. For this purpose biodegradation experiments were performed, using specifically designed soil column bioreactors. For the experiment, coal-contaminated soil was prepared, which contains high molecular weight hydrocarbons at high concentration (approx. 55.5 mgC g-drysoil{sup -1}). The experiment was carried out in two different conditions: sulfate reducing (SR) condition (SO{sub 4}{sup 2-}=10 mmol 1{sup -1} in the liquid medium) and control condition (SO{sub 4}{sup 2-} {lt} 0.5 mmol 1{sup -1}). Although no degradation was observed under the control condition, the resin fraction decreased to half (from 6,541 to 3,386 mgC g-soil{sup -1}) under SR condition, with the concomitant increase of two PAHs (phenanthrene and fluoranthene 9 and 2.5 times, respectively). From these results, we could conclude that high molecular hydrocarbons were biodegradable and transformed to low molecular weight PAHs under the sulfate-reducing condition. Since these PAHs are known to be biologically degraded under aerobic condition, a serial combination of anaerobic (sulfate reducing) and then aerobic bioremediations could be effective and useful for the soil pollution by petroleum and/or coal derived hydrocarbons.

  8. Proteogenomic monitoring of Geobacter physiology during stimulated uranium bioremediation.

    Science.gov (United States)

    Wilkins, Michael J; Verberkmoes, Nathan C; Williams, Kenneth H; Callister, Stephen J; Mouser, Paula J; Elifantz, Hila; N'guessan, A Lucie; Thomas, Brian C; Nicora, Carrie D; Shah, Manesh B; Abraham, Paul; Lipton, Mary S; Lovley, Derek R; Hettich, Robert L; Long, Philip E; Banfield, Jillian F

    2009-10-01

    Implementation of uranium bioremediation requires methods for monitoring the membership and activities of the subsurface microbial communities that are responsible for reduction of soluble U(VI) to insoluble U(IV). Here, we report a proteomics-based approach for simultaneously documenting the strain membership and microbial physiology of the dominant Geobacter community members during in situ acetate amendment of the U-contaminated Rifle, CO, aquifer. Three planktonic Geobacter-dominated samples were obtained from two wells down-gradient of acetate addition. Over 2,500 proteins from each of these samples were identified by matching liquid chromatography-tandem mass spectrometry spectra to peptides predicted from seven isolate Geobacter genomes. Genome-specific peptides indicate early proliferation of multiple M21 and Geobacter bemidjiensis-like strains and later possible emergence of M21 and G. bemidjiensis-like strains more closely related to Geobacter lovleyi. Throughout biostimulation, the proteome is dominated by enzymes that convert acetate to acetyl-coenzyme A and pyruvate for central metabolism, while abundant peptides matching tricarboxylic acid cycle proteins and ATP synthase subunits were also detected, indicating the importance of energy generation during the period of rapid growth following the start of biostimulation. Evolving Geobacter strain composition may be linked to changes in protein abundance over the course of biostimulation and may reflect changes in metabolic functioning. Thus, metagenomics-independent community proteogenomics can be used to diagnose the status of the subsurface consortia upon which remediation biotechnology relies.

  9. Bioremediation of polyaromatic hydrocarbons (PAHs using rhizosphere technology

    Directory of Open Access Journals (Sweden)

    Sandeep Bisht

    2015-03-01

    Full Text Available The remediation of polluted sites has become a priority for society because of increase in quality of life standards and the awareness of environmental issues. Over the past few decades there has been avid interest in developing in situ strategies for remediation of environmental contaminants, because of the high economic cost of physicochemical strategies, the biological tools for remediation of these persistent pollutants is the better option. Major foci have been considered on persistent organic chemicals i.e.polyaromatic hydrocarbons (PAHs due to their ubiquitous occurrence, recalcitrance, bioaccumulation potential and carcinogenic activity. Rhizoremediation, a specific type of phytoremediation that involves both plants and their associated rhizospheric microbes is the creative biotechnological approach that has been explored in this review. Moreover, in this review we showed the significance of rhizoremediation of PAHs from other bioremediation strategies i.e. natural attenuation, bioaugmentation and phytoremediation and also analyze certain environmental factor that may influence the rhizoremediation technique. Numerous bacterial species were reported to degrade variety of PAHs and most of them are isolated from contaminated soil, however few reports are available from non contaminated soil. Pseudomonas aeruginosa, Pseudomons fluoresens, Mycobacterium spp., Haemophilus spp., Rhodococcus spp., Paenibacillus spp. are some of the commonly studied PAH-degrading bacteria. Finally, exploring the molecular communication between plants and microbes, and exploiting this communication to achieve better results in the elimination of contaminants, is a fascinating area of research for future perspective.

  10. Apparatus and method for phosphate-accelerated bioremediation

    Science.gov (United States)

    Looney, B.B.; Phelps, T.J.; Hazen, T.C.; Pfiffner, S.M.; Lombard, K.H.; Borthen, J.W.

    1994-01-01

    An apparatus and method for supplying a vapor-phase nutrient to contaminated soil for in situ bioremediation. The apparatus includes a housing adapted for containing a quantity of the liquid nutrient, a conduit in fluid communication with the interior of the housing, means for causing a gas to flow through the conduit, and means for contacting the gas with the liquid so that a portion thereof evaporates and mixes with the gas. The mixture of gas and nutrient vapor is delivered to the contaminated site via a system of injection and extraction wells configured to the site. The mixture has a partial pressure of vaporized nutrient that is no greater than the vapor pressure of the liquid. If desired, the nutrient and/or the gas may be heated to increase the vapor pressure and the nutrient concentration of the mixture. Preferably, the nutrient is a volatile, substantially nontoxic and nonflammable organic phosphate that is a liquid at environmental temperatures, such as triethyl phosphate or tributyl phosphate.

  11. Potential of Penicillium Species in the Bioremediation Field

    Directory of Open Access Journals (Sweden)

    Ana Lúcia Leitão

    2009-04-01

    Full Text Available The effects on the environment of pollution, particularly that caused by various industrial activities, have been responsible for the accelerated fluxes of organic and inorganic matter in the ecosphere. Xenobiotics such as phenol, phenolic compounds, polycyclic aromatic hydrocarbons (PAHs, and heavy metals, even at low concentrations, can be toxic to humans and other forms of life. Many of the remediation technologies currently being used for contaminated soil and water involve not only physical and chemical treatment, but also biological processes, where microbial activity is the responsible for pollutant removal and/or recovery. Fungi are present in aquatic sediments, terrestrial habitats and water surfaces and play a significant part in natural remediation of metal and aromatic compounds. Fungi also have advantages over bacteria since fungal hyphae can penetrate contaminated soil, reaching not only heavy metals but also xenobiotic compounds. Despite of the abundance of such fungi in wastes, penicillia in particular have received little attention in bioremediation and biodegradation studies. Additionally, several studies conducted with different strains of imperfecti fungi, Penicillium spp. have demonstrated their ability to degrade different xenobiotic compounds with low co-substrate requirements, and could be potentially interesting for the development of economically feasible processes for pollutant transformation.

  12. Bioremediation of aflatoxins by some reference fungal strains.

    Science.gov (United States)

    El-Shiekh, Hussein H; Mahdy, Hesham M; El-Aaser, Mahmoud M

    2007-01-01

    Aspergillus parasiticus RCMB 002001 (2) producing four types of aflatoxins B1, B2, G1, and G2 was used in this study as an aflatoxin-producer. Penicillium griseofulvum, P. urticae, Paecilomyces lilacinus, Trichoderma viride, Candida utilis, Saccharomyces cerevisiae as well as a non-toxigenic strain of Aspergillus flavus were found to be able to exhibit growth on aflatoxin B1-containing medium up to a concentration of 500 ppb. It was also found that several fungal strains exhibited the growth in co-culture with A. parasiticus, natural aflatoxins producer, and were able to decreased the total aflatoxin concentration, resulting in the highest inhibition percentage of 67.2% by T viride, followed by P. lilacinus, P. griseofulvum, S. cerevisiae, C. utilis, P. urticae, Rhizopus nigricans and Mucor rouxii with total aflatoxin inhibition percentage of 53.9, 52.4, 52, 51.7, 44, 38.2 and 35.4%, respectively. The separation of bioremediation products using GC/MS revealed that the toxins were degraded into furan moieties.

  13. Apparatus and method for phosphate-accelerated bioremediation

    Science.gov (United States)

    Looney, Brian B.; Pfiffner, Susan M.; Phelps, Tommy J.; Lombard, Kenneth H.; Hazen, Terry C.; Borthen, James W.

    1998-01-01

    An apparatus and method for supplying a vapor-phase nutrient to contaminated soil for in situ bioremediation. The apparatus includes a housing adapted for containing a quantity of the liquid nutrient, a conduit in communication with the interior of the housing, means for causing a gas to flow through the conduit, and means for contacting the gas with the liquid so that a portion thereof evaporates and mixes with the gas. The mixture of gas and nutrient vapor is delivered to the contaminated site via a system of injection and extraction wells configured to the site and provides for the use of a passive delivery system. The mixture has a partial pressure of vaporized nutrient that is no greater than the vapor pressure of the liquid. If desired, the nutrient and/or the gas may be heated to increase the vapor pressure and the nutrient concentration of the mixture. Preferably, the nutrient is a volatile, substantially nontoxic and nonflammable organic phosphate that is a liquid at environmental temperatures, such as triethyl phosphate or tributyl phosphate.

  14. USING PHYTOREMEDIATION AND BIOREMEDIATION FOR PROTECTION SOIL NEAR GRAVEYARD

    Directory of Open Access Journals (Sweden)

    Katarzyna Ignatowicz

    2016-07-01

    Full Text Available The aim of present research was to assess the usefulness of Basket willow (Salix viminalis to phytoremediation and bioremediation of sorption subsoil contaminated with pesticides. Studies upon purification of sorption material consisting of a soil and composting sewage sludge were conducted under pot experiment conditions. The study design included control pot along with 3 other ones polluted with pesticides. The vegetation season has lasted since spring till late autumn 2015. After acclimatization, the mixture of chloroorganic pesticides was added into 3 experimental pots. After harvest, it was found that pesticide contents in sorption subsoil (from 0.0017 to 0.0087 mg kg DM were much higher than in control soil (from 0.0005 to 0.0027 mg kg DM. Achieved results initially indicate that Basket willow (Salix viminalis can be used for reclamation of soils contaminated with pesticides, particularly for vitality prolongation of sorption barrier around the pesticide burial area. In future, it would allow for applying the sorption screen around pesticide burial area, which reduces pesticide migration into the environment, and grown energetic plants – through phytoremediation – would prolong the sorbent vitality and remove pesticides from above ground parts by means of combustion.

  15. Microbial Studies Supporting Implementation of In Situ Bioremediation at TAN

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Joan Marie; Matthern, Gretchen Elise; Rae, Catherine; Ely, R. L.

    2000-11-01

    The Idaho National Engineering and Environmental Laboratory is evaluating in situ bioremediation of contaminated groundwater at its Test Area North Facility. To determine feasibility, microcosm and bioreactor studies were conducted to ascertain the ability of indigenous microbes to convert trichloroethene and dichloroethene to non-hazardous byproducts under aerobic and anaerobic conditions, and to measure the kinetics of microbial reactions associated with the degradation process. Microcosms were established from core samples and groundwater obtained from within the contaminant plume. These microcosms were amended with nutrients, under aerobic and anaerobic conditions, to identify electron donors capable of stimulating the degradation process. Results of the anaerobic microcosm studies showed that lactate, acetate and propionate amendments stimulated indigenous cell growth and functioned as effective substrates for reductive degradation of chloroethenes. Bioreactors inoculated with cultures from these anaerobic microcosms were operated under a batch mode for 42 days then converted to a fed-batch mode and operated at a 53-day hydraulic residence time. It was demonstrated that indigenous microbes capable of complete anaerobic reductive dechlorination are present in the subject well. It was also demonstrated that aerobic microbes capable of oxidizing chlorinated compounds produced by anaerobic reductive dechlorination are present. Kinetic data suggest that controlling the type and concentration of electron donors can increase trichlorethene conversion rates. In the event that complete mineralization of trichlorethene does not occur following stimulation, and anaerobic/aerobic treatment scheme is feasible.

  16. Aspergillus flavus: A potential Bioremediator for oil contaminated soils

    Directory of Open Access Journals (Sweden)

    Y.Avasn Maruthi

    2013-02-01

    Full Text Available Biodegradation is cost-effective, environmentally friendly treatment for oily contaminated sites by the use of microorganisms. In this study, laboratory experiments were conducted to establish the performance of fungal isolates in degradation of organic compounds contained in soils contaminated with petrol and diesel. As a result of the laboratory screening, two natural fungal strains capable of degrading total organic carbons (TOC were prepared from isolates enriched from the oil contaminated sites. Experiments were conducted in Erlenmeyer flasks under aerobic conditions, with TOC removal percentage varied from 0.7 to 32% depending on strains type and concentration. Strains Phanerocheate chrysosporium and Aspergillus niger exhibited the highest TOC removal percentage of 32 and 21%, respectively, before nutrient addition. TOC removal rate was enhanced after addition of nutrients to incubated flasks. The highest TOC reduction (45% was estimated after addition of combination of nitrogen, phosphorus and sulphur to Phanerocheate chrysosporium strains. Results of experimental work carried out elucidate that the fungi like Phanerocheate chrysosporium and Aspergillus niger were capabled of producing enzymes at a faster rate to decompose the substrate hydrocarbon and released more CO2 and hence these potential fungi can be utilized effectively as agents of biodegradation in waste recycling process and Bioremediation of oil contaminated sites.

  17. Microbial aspects of acid mine drainage and its bioremediation

    Institute of Scientific and Technical Information of China (English)

    K.A.NATARAJAN

    2008-01-01

    The role of chemolithotrophs such as Acidithiobacillus ferrooxidans,Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans which were isolated from some abandoned mines and processed waste tailings in the generation of acid mine drainage and toxic metal dissolution was discussed.Mechanisms of acid formation and dissolution of copper,zinc,iron and arsenic from copper,lead-zinc and arsenopyrite-bearing sulfide ores and tailings were established in the presence of Acidithiobacillus group of bacteria.Sulphate Reducing Bacteria(SRB) isolated from the above mine sites could be used to precipitate dissolved metals such as copper,zinc,iron and arsenic.Arsenic bioremediation was demonstrated through the use of native microorganisms such Thiomonas spp.which could oxidize arsenite to arsenate.Bioremoval of arsenic through the use of jarosite precipitates generated by Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans was also found to be very effective.Biotechnological processes hold great promise in the remediation of acid mine drainage and efficient removal of toxic metal ions such as copper,zinc and arsenic.

  18. The bioremediation potential of marine sandy sediment microbiota

    Directory of Open Access Journals (Sweden)

    Dan Răzvan POPOVICIU

    2012-11-01

    Full Text Available The natural microbiota from marine sandy sediments on the Romanian sea coast was tested for resilience in case of hydrocarbon contamination, for estimating the number of (culturable hydrocarbon and lipid oil-degrading microorganisms and for determining the influence of inorganic nitrate and phosphate nutrients on hydrocarbon spill bioremediation process, by microcosm experiments.Results show that hydrocarbon contamination affects the bacteriobenthos both in terms of cell numbers and composition. Bacterial numbers showed a rapid decrease (28% in four days, followed by a relatively fast recovery (two weeks. The pollution favoured the increase of Gram-positive bacterial proportion (from around 25% to 33%Sandy sediment microbiota in both sites studied contained microorganisms able to use mineral or lipid oils as sole carbon sources, usually around 103-104/cm3, with variations according to the sediment grain size and substrate used.The biostimulation experiments showed that, in absence of water dynamism (and, implicitly, an efficient oxygenation, the addition of nitrogen and phosphorus can be ineffective and even inhibit the remediation process, probably due to eutrophication.

  19. Bioremediation of petroleum hydrocarbons: catabolic genes, microbial communities, and applications.

    Science.gov (United States)

    Fuentes, Sebastián; Méndez, Valentina; Aguila, Patricia; Seeger, Michael

    2014-06-01

    Bioremediation is an environmental sustainable and cost-effective technology for the cleanup of hydrocarbon-polluted soils and coasts. In spite of that longer times are usually required compared with physicochemical strategies, complete degradation of the pollutant can be achieved, and no further confinement of polluted matrix is needed. Microbial aerobic degradation is achieved by the incorporation of molecular oxygen into the inert hydrocarbon molecule and funneling intermediates into central catabolic pathways. Several families of alkane monooxygenases and ring hydroxylating dioxygenases are distributed mainly among Proteobacteria, Actinobacteria, Firmicutes and Fungi strains. Catabolic routes, regulatory networks, and tolerance/resistance mechanisms have been characterized in model hydrocarbon-degrading bacteria to understand and optimize their metabolic capabilities, providing the basis to enhance microbial fitness in order to improve hydrocarbon removal. However, microbial communities taken as a whole play a key role in hydrocarbon pollution events. Microbial community dynamics during biodegradation is crucial for understanding how they respond and adapt to pollution and remediation. Several strategies have been applied worldwide for the recovery of sites contaminated with persistent organic pollutants, such as polycyclic aromatic hydrocarbons and petroleum derivatives. Common strategies include controlling environmental variables (e.g., oxygen availability, hydrocarbon solubility, nutrient balance) and managing hydrocarbon-degrading microorganisms, in order to overcome the rate-limiting factors that slow down hydrocarbon biodegradation.

  20. Transient heterogeneity in an aquifer undergoing bioremediation of hydrocarbons.

    Science.gov (United States)

    Schillig, P C; Devlin, J F; Roberts, J A; Tsoflias, G P; McGlashan, M A

    2011-01-01

    Localized, transient heterogeneity was studied in a sand aquifer undergoing benzene, toluene, ethylbenzene, and xylene bioremediation using a novel array of multilevel, in situ point velocity probes (PVPs). The experiment was conducted within a sheet-pile alleyway to maintain a constant average flow direction through time. The PVPs measured changes in groundwater velocity direction and magnitude at the centimeter scale, making them ideal to monitor small-scale changes in hydraulic conductivity (K). Velocities were shown to vary nonuniformly by up to a factor of 3 when a source of oxygen was established down-gradient of the petroleum spill. In spite of these local variations, the average groundwater velocity within the 7 m × 20 m sheet-piled test area only varied within ± 25%. The nonuniform nature of the velocity variations across the gate indicated that the changes were not due solely to seasonal hydraulic gradient fluctuations. At the conclusion of the experiment, microbial biomass levels in the aquifer sediments was approximately 1 order of magnitude higher in the oxygen-amended portion of the aquifer than at the edge of the plume or in locations up-gradient of the source. These data suggest that the transient velocities resulted, at least in part, from enhanced biological activity that caused transient heterogeneities in the porous medium.

  1. Bioremediation of polyaromatic hydrocarbons (PAHs) using rhizosphere technology.

    Science.gov (United States)

    Bisht, Sandeep; Pandey, Piyush; Bhargava, Bhavya; Sharma, Shivesh; Kumar, Vivek; Sharma, Krishan D

    2015-03-01

    The remediation of polluted sites has become a priority for society because of increase in quality of life standards and the awareness of environmental issues. Over the past few decades there has been avid interest in developing in situ strategies for remediation of environmental contaminants, because of the high economic cost of physicochemical strategies, the biological tools for remediation of these persistent pollutants is the better option. Major foci have been considered on persistent organic chemicals i.e. polyaromatic hydrocarbons (PAHs) due to their ubiquitous occurrence, recalcitrance, bioaccumulation potential and carcinogenic activity. Rhizoremediation, a specific type of phytoremediation that involves both plants and their associated rhizospheric microbes is the creative biotechnological approach that has been explored in this review. Moreover, in this review we showed the significance of rhizoremediation of PAHs from other bioremediation strategies i.e. natural attenuation, bioaugmentation and phytoremediation and also analyze certain environmental factor that may influence the rhizoremediation technique. Numerous bacterial species were reported to degrade variety of PAHs and most of them are isolated from contaminated soil, however few reports are available from non contaminated soil. Pseudomonas aeruginosa , Pseudomons fluoresens , Mycobacterium spp., Haemophilus spp., Rhodococcus spp., Paenibacillus spp. are some of the commonly studied PAH-degrading bacteria. Finally, exploring the molecular communication between plants and microbes, and exploiting this communication to achieve better results in the elimination of contaminants, is a fascinating area of research for future perspective.

  2. Feasibility of electrokinetic oxygen supply for soil bioremediation purposes.

    Science.gov (United States)

    Mena Ramírez, E; Villaseñor Camacho, J; Rodrigo Rodrigo, M A; Cañizares Cañizares, P

    2014-12-01

    This paper studies the possibility of providing oxygen to a soil by an electrokinetic technique, so that the method could be used in future aerobic polluted soil bioremediation treatments. The oxygen was generated from the anodic reaction of water electrolysis and transported to the soil in a laboratory-scale electrokinetic cell. Two variables were tested: the soil texture and the voltage gradient. The technique was tested in two artificial soils (clay and sand) and later in a real silty soil, and three voltage gradients were used: 0.0 (control), 0.5, and 1.0 V cm(-1). It was observed that these two variables strongly influenced the results. Oxygen transport into the soil was only available in the silty and sandy soils by oxygen diffusion, obtaining high dissolved oxygen concentrations, between 4 and 9 mg L(-1), useful for possible aerobic biodegradation processes, while transport was not possible in fine-grained soils such as clay. Electro-osmotic flow did not contribute to the transport of oxygen, and an increase in voltage gradients produced higher oxygen transfer rates. However, only a minimum fraction of the electrolytically generated oxygen was efficiently used, and the maximum oxygen transport rate observed, approximately 1.4 mgO2 L(-1)d(-1), was rather low, so this technique could be only tested in slow in-situ biostimulation processes for organics removal from polluted soils.

  3. A comparison of organophosphate degradation genes and bioremediation applications.

    Science.gov (United States)

    Iyer, Rupa; Iken, Brian; Damania, Ashish

    2013-12-01

    Organophosphates (OPs) form the bulk of pesticides that are currently in use around the world accounting for more than 30% of the world market. They also form the core for many nerve-based warfare agents including sarin and soman. The widespread use and the resultant build-up of OP pesticides and chemical nerve agents has led to the development of major health problems due to their extremely toxic interaction with any biological system that encounters them. Growing concern over the accumulation of OP compounds in our food products, in the soils from which they are harvested and in wastewater run-off has fuelled a growing interest in microbial biotechnology that provides cheap, efficient OP detoxification to supplement expensive chemical methods. In this article, we review the current state of knowledge of OP pesticide and chemical agent degradation and attempt to clarify confusion over identification and nomenclature of two major families of OP-degrading enzymes through a comparison of their structure and function. The isolation, characterization, utilization and manipulation of the major detoxifying enzymes and the molecular basis of degradation of OP pesticides and chemical nerve agents are discussed as well as the achievements and technological advancements made towards the bioremediation of such compounds.

  4. Potential of Penicillium Species in the Bioremediation Field

    Science.gov (United States)

    Leitão, Ana Lúcia

    2009-01-01

    The effects on the environment of pollution, particularly that caused by various industrial activities, have been responsible for the accelerated fluxes of organic and inorganic matter in the ecosphere. Xenobiotics such as phenol, phenolic compounds, polycyclic aromatic hydrocarbons (PAHs), and heavy metals, even at low concentrations, can be toxic to humans and other forms of life. Many of the remediation technologies currently being used for contaminated soil and water involve not only physical and chemical treatment, but also biological processes, where microbial activity is the responsible for pollutant removal and/or recovery. Fungi are present in aquatic sediments, terrestrial habitats and water surfaces and play a significant part in natural remediation of metal and aromatic compounds. Fungi also have advantages over bacteria since fungal hyphae can penetrate contaminated soil, reaching not only heavy metals but also xenobiotic compounds. Despite of the abundance of such fungi in wastes, penicillia in particular have received little attention in bioremediation and biodegradation studies. Additionally, several studies conducted with different strains of imperfecti fungi, Penicillium spp. have demonstrated their ability to degrade different xenobiotic compounds with low co-substrate requirements, and could be potentially interesting for the development of economically feasible processes for pollutant transformation. PMID:19440525

  5. Nanoassembly of immobilized ligninolytic enzymes for biocatalysis, bioremediation, and biosensing

    Science.gov (United States)

    Kuila, Debasish; Tien, Ming; Lvov, Yuri M.; McShane, Michael J.; Aithal, Rajendra K.; Singh, Saurabh; Potluri, Avinash; Kaul, Swati; Patel, Devendra S.; Krishna, Gopal

    2004-12-01

    Extracellular enzymes, lignin peroxidase (LiP) and manganese peroxidase (MnP) from white rot fungus Phanerochaete chrysosoporium, have been shown to degrade various harmful organic compounds ranging from chlorinated compounds to polycyclic aromatic hydrocarbons (PAH) to polymeric dyes. The problems in using immobilized enzymes for biocatalysis/bioremediation are their loss of activity and long-term stability. To address these issues, adsorption by layer-by-layer assembly (LbL) using polyelectrolytes, entrapment using gelatin, and chmisorption using coupling reagents have been investigated. In order to increase surface area for catalysis, porous silicon, formed by electrochemical etching of silicon, has been considered. The efficacy of these extremely stable nanoassemblies towards degradation of model organic compounds-veratryl alcohol (VA and 2,6-dimethoxyphenol (DMP)-in aqueous and in a mixture of aqueous/acetone has already been demonstrated. In parallel, we are pursuing development of sensors using these immobilized enzymes. Experiments carried out in solution show that NO can reversibly bind Ferri-LiP to produce a diamagnetic complex with a distinct change in its optical spectrum. NO can be photolyzed off to produce the spectrum of native paramagnetic ferri-species. Preliminary data on the detection of NO by LiP, based on surface plasmon resonance (SPR) using fiber optic probe, are presented.

  6. Bioremediation of an area contaminated by a fuel spill.

    Science.gov (United States)

    Vallejo, B; Izquierdo, A; Blasco, R; Pérez del Campo, P; Luque de Castro, M D

    2001-06-01

    In order to decontaminate a large area of restricted access contaminated by a fuel spill, laboratory and field studies were developed in two steps: (a) monitoring of the laboratory experiment on bacterial growth under aerobic and anaerobic conditions with and without addition of nutrients; and (b) use of the best conditions obtained in (a) for the decontamination of the soil. A hydraulic barrier was installed both to clean the aquifer and to avoid migration of hydrocarbons as a consequence of their solution in the groundwater and subsequent displacement. The objective was to create an ideal environment for the treatment of the affected area that favoured the growth of the indigenous bacteria (Pseudomonas and Arthrobacter) that biodegrade the hydrocarbons. Monitoring of the changes in the total concentration of petroleum hydrocarbons in the soil subjected to bacterial action was performed by gas chromatography. In a field study, the progress of biodegradation of hydrocarbons was evaluated in situ by changes in subsurface CO2/O2 levels by means of an analyser equipped with an infrared detector. Biostimulation and oxygen were the most influential factors for the biodegradation of the hydrocarbons. The use of bioventing of the soil was shown as an excellent technology to promote in situ bioremediation of the polluted area.

  7. Proteogenomic monitoring of Geobacter physiology during stimulated uranium bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Wilkins, Mike [University of California, Berkeley; Verberkmoes, Nathan C [ORNL; Williams, Ken [Lawrence Berkeley National Laboratory (LBNL); Callister, Stephen J [Pacific Northwest National Laboratory (PNNL); Mouser, Paula J [University of Massachusetts, Amherst; Elifantz, Hila [University of Massachusetts, Amherst; N' Guessan, A. Lucie [University of Massachusetts, Amherst; Thomas, Brian [University of California, Berkeley; Nicora, Carrie D. [Pacific Northwest National Laboratory (PNNL); Shah, Manesh B [ORNL; Abraham, Paul E [ORNL; Lipton, Mary S [Pacific Northwest National Laboratory (PNNL); Lovley, Derek [University of Massachusetts, Amherst; Hettich, Robert {Bob} L [ORNL; Long, Phil [Pacific Northwest National Laboratory (PNNL); Banfield, Jillian F. [University of California, Berkeley

    2009-01-01

    Implementation of uranium bioremediation requires methods to monitor the membership and activities of the subsurface microbial communities that are responsible for reduction of soluble U(VI) to insoluble U(IV). Here we report a proteomics-based approach to simultaneously document strain membership and microbial physiology of the dominant Geobacter community members during in situ acetate amendment of the U-contaminated Rifle, CO aquifer. Three planktonic Geobacter-dominated samples were obtained from two wells down-gradient of acetate addition. Over 2,500 proteins from each of these samples were identified by matching LC MS/MS spectra to peptides predicted from 7 isolate Geobacter genomes. Genome-specific peptides indicate early proliferation of multiple M21 and G. bemidjiensis like strains and later possible emergence of M21 and G. bemidjiensis like strains more closely related to G. lovleyi. Throughout biostimulation, the proteome is dominated by enzymes that convert acetate to acetyl-CoA and pyruvate for central metabolism while abundant peptides matching TCA cycle proteins and ATP synthase subunits were also detected, indicating the importance of energy generation during the period of rapid growth following the start of biostimulation. Evolving Geobacter strain composition may be linked to changes in protein abundance over the course of biostimulation and may reflect changes in metabolic functioning. Thus, metagenomics independent community proteogenomics can be used to diagnose the status of the subsurface consortia upon which remediation biotechnology relies.

  8. Proteogenomic monitoring of Geobacter physiology during stimulated uranium bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Wilkins, Michael J.; VerBerkmoes, Nathan C.; Williams, Kenneth H.; Callister, Stephen J.; Mouser, Paula; Elifantz, H.; N' Guessan, A. Lucie; Thomas, Brian C.; Nicora, Carrie D.; Shah, Manesh B.; Abraham, Paul; Lipton, Mary S.; Lovely, Derek R.; Hettich, Robert L.; Long, Philip E.; Banfield, Jillian F.

    2009-10-01

    Implementation of uranium bioremediation requires methods to monitor the membership and activities of the subsurface microbial communities that are responsible for reduction of soluble U(VI) to insoluble U(IV). Here we report a proteomics-based approach to simultaneously document strain membership and microbial physiology of the dominant Geobacter community members during in situ acetate amendment of the U-contaminated Rifle, CO aquifer. Three planktonic Geobacter-dominated samples were obtained from two wells down-gradient of acetate addition. Over 2,500 proteins from each of these samples were identified by matching LC MS/MS spectra to peptides predicted from 7 isolate Geobacter genomes. Genome-specific peptides indicate early proliferation of multiple M21 and G. bemidjiensis–like strains and later possible emergence of M21 and G. bemidjiensis–like strains more closely related to G. lovleyi. Throughout biostimulation, the proteome is dominated by enzymes that convert acetate to acetyl-CoA and pyruvate for central metabolism while abundant peptides matching TCA cycle proteins and ATP synthase subunits were also detected, indicating the importance of energy generation during the period of rapid growth following the start of biostimulation. Evolving Geobacter strain composition may be linked to changes in protein abundance over the course of biostimulation and may reflect changes in metabolic functioning. Thus, metagenomics independent community proteogenomics can be used to diagnose the status of the subsurface consortia upon which remediation biotechnology relies.

  9. Enzymatic bioremediation of cashew nut shell liquid contamination.

    Science.gov (United States)

    Cheriyan, Soly; Abraham, Emilia T

    2010-04-15

    Cashew nut shell liquid (CNSL), a by-product of the cashew kernel industry, is a caustic, viscous, dark liquid. The process is done manually, which leaves stains on the hands of the workers. The aim was to find the utility of enzymes, oxidoreductases and proteases for the bioremediation of CNSL, which contains phenolics, mainly cardanol (60-65%). The results show that peroxidase reduced the color of the CNSL solution by polymerization and precipitation, where as laccase, papain and fungal and bacterial protease degraded the phenolic constituents. The degradation was mainly at the double bonds of the C15 hydrocarbon chain of the cardanol. To improve the enzyme stability, laccase and papain was separately immobilized in alginate-starch beads. Immobilized laccase can degrade 28.6% CNSL within 2 h, where as papain takes longer duration, and at 73 h, the adsorbed phenols on the alginate (45.86%) also got degraded. MALDI-TOF MS revealed that, immobilized laccase-papain beads combination; 1:1 (w/w) degraded 60% of the cardanol and some phenolic compounds having molecular mass of 374, 390 and 407. These beads are active and stable in aqueous media, can be used to prepare a mild, nontoxic, ecofriendly, cost effective hand wash solution for the removal of phenolic stains.

  10. Bioremediation of toxic heavy metals using acidothermophilic autotrophes.

    Science.gov (United States)

    Umrania, Valentina V

    2006-07-01

    Investigations were carried out to isolate microbial strains from soil, mud and water samples from metallurgically polluted environment for bioremediation of toxic heavy metals. As a result of primary and secondary screening various 72 acidothermophilic autotrophic microbes were isolated and adapted for metal tolerance and biosorption potentiality. The multi-metal tolerance was developed with higher gradient of concentrations of Ag, As, Bi, Cd, Cr, Co, Cu, Hg, Li, Mo, Pb, Sn and Zn. The isolates were checked for their biosolubilization ability with copper containing metal sulfide ores. In case of chalcopyrite 85.82% and in covellite as high as 97.5% copper solubilization occurred in presence of 10(-3) M multi-heavy metals on fifth day at 55 degrees C and pH 2.5. Chemical analyses were carried out by inductively coupled plasma spectroscopy (ICP) for metal absorption. The selected highly potential isolate (ATh-14) showed maximum adsorption of Ag 73%, followed by Pb 35%, Zn 34%, As 19%, Ni 15% and Cr 9% in chalcopyrite.

  11. Bioremediation potential of microorganisms derived from petroleum reservoirs.

    Science.gov (United States)

    Dellagnezze, Bruna Martins; de Sousa, Gabriel Vasconcelos; Martins, Laercio Lopes; Domingos, Daniela Ferreira; Limache, Elmer E G; de Vasconcellos, Suzan Pantaroto; da Cruz, Georgiana Feitosa; de Oliveira, Valéria Maia

    2014-12-15

    Bacterial strains and metagenomic clones, both obtained from petroleum reservoirs, were evaluated for petroleum degradation abilities either individually or in pools using seawater microcosms for 21 days. Gas Chromatography-Flame Ionization Detector (GC-FID) and Gas Chromatography-Mass Spectrometry (GC-MS) analyses were carried out to evaluate crude oil degradation. The results showed that metagenomic clones 1A and 2B were able to biodegrade n-alkanes (C14 to C33) and isoprenoids (phytane and pristane), with rates ranging from 31% to 47%, respectively. The bacteria Dietzia maris CBMAI 705 and Micrococcus sp. CBMAI 636 showed higher rates reaching 99% after 21 days. The metagenomic clone pool biodegraded these compounds at rates ranging from 11% to 45%. Regarding aromatic compound biodegradation, metagenomic clones 2B and 10A were able to biodegrade up to 94% of phenanthrene and methylphenanthrenes (3-MP, 2-MP, 9-MP and 1-MP) with rates ranging from 55% to 70% after 21 days, while the bacteria Dietzia maris CBMAI 705 and Micrococcus sp. CBMAI 636 were able to biodegrade 63% and up to 99% of phenanthrene, respectively, and methylphenanthrenes (3-MP, 2-MP, 9-MP and 1-MP) with rates ranging from 23% to 99% after 21 days. In this work, isolated strains as well as metagenomic clones were capable of degrading several petroleum compounds, revealing an innovative strategy and a great potential for further biotechnological and bioremediation applications.

  12. Proteogenomic monitoring of Geobacter physiology during stimulated uranium bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Wilkins, M.J.; VerBerkmoes, N.C.; Williams, K.H.; Callister, S.J.; Mouser, P.J.; Elifantz, H.; N' Guessan, A.L.; Thomas, B.C.; Nicora, C.D.; Shah, M.B.; Lipton, M.S.; Lovley, D.R.; Hettich, R.L.; Long, P.E.; Banfield, J.F.; Abraham, P.

    2009-08-01

    Implementation of uranium bioremediation requires methods for monitoring the membership and activities of the subsurface microbial communities that are responsible for reduction of soluble U(VI) to insoluble U(IV). Here, we report a proteomics-based approach for simultaneously documenting the strain membership and microbial physiology of the dominant Geobacter community members during in situ acetate amendment of the U-contaminated Rifle, CO, aquifer. Three planktonic Geobacter-dominated samples were obtained from two wells down-gradient of acetate addition. Over 2,500 proteins from each of these samples were identified by matching liquid chromatography-tandem mass spectrometry spectra to peptides predicted from seven isolate Geobacter genomes. Genome-specific peptides indicate early proliferation of multiple M21 and Geobacter bemidjiensis-like strains and later possible emergence of M21 and G. bemidjiensis-like strains more closely related to Geobacter lovleyi. Throughout biostimulation, the proteome is dominated by enzymes that convert acetate to acetyl-coenzyme A and pyruvate for central metabolism, while abundant peptides matching tricarboxylic acid cycle proteins and ATP synthase subunits were also detected, indicating the importance of energy generation during the period of rapid growth following the start of biostimulation. Evolving Geobacter strain composition may be linked to changes in protein abundance over the course of biostimulation and may reflect changes in metabolic functioning. Thus, metagenomics-independent community proteogenomics can be used to diagnose the status of the subsurface consortia upon which remediation biotechnology relies.

  13. J.R. SIMPLOT EX-SITU BIOREMEDIATION TECHNOLOGY FOR TREATMENT OF TNT-CONTAMINATED SOILS - INNOVATIVE TECHNOLOGY EVALUATION REPORT

    Science.gov (United States)

    This report summarizes the findings of the second evaluation of the J.R. Simplot Ex-situ Bioremediation Technology also known as the Simplot Anaerobic Bioremediation (SABRE™) process. This technology was developed by the J.R. Simplot Company to biologically degrade nitroaromatic...

  14. The sociality of bioremediation: Hijacking the social lives of microbial populations to clean up heavy metal contamination

    OpenAIRE

    O'Brien, Siobhan; Buckling, Angus

    2015-01-01

    Bioremediation to remove toxic heavy metals from the environment relies on metal‐tolerant plants or microbes to do the job, but with varying degrees of success. Understanding the ecology and evolution of metal‐resistant bacterial societies could drastically improve the efficiency of microbial bioremediation.

  15. Evaluation of biodiesel as bioremediation agent for the treatment of the shore affected by the heavy oil spill of the Prestige.

    Science.gov (United States)

    Fernández-Alvarez, P; Vila, J; Garrido, J M; Grifoll, M; Feijoo, G; Lema, J M

    2007-08-25

    The efficiency of different bioremediation products (nutrients, microorganisms and biodiesel) was tested using tiles located in both the supra-littoral and intertidal zones of a beach that was affected by the heavy oil spill of the Prestige. Neither nutrients nor microorganisms meant an improvement with respect to the natural processes. The addition of biodiesel improved the appearance of the treated tiles and apparently accelerated the degradation of the aliphatic and aromatic fractions of the residual fuel oil. Nevertheless, PAHs degradation was similar and very high in all the treatments (80-85% after 60 days). On the other hand, the evolution with time of the amount of vanadium was similar to that of 17alpha(H),21beta(H)-hopane, so it was concluded that vanadium could also be used to estimate the extent of oil degradation in the field. These results also suggested that the residual fuel oil mineralization was very low throughout 1 year in all the treatments. Moreover, the increase of the oxygen content of the residual oil from around 1% till 4-8% indicated that the partial oxidation of hydrocarbons took place, and that the hydrocarbon oxidation products accumulated in the polar fractions. In general, the results pointed out that bioremediation techniques were not suitable for the recovery of shores affected by heavy oil spills.

  16. Spatializing Time

    DEFF Research Database (Denmark)

    Thomsen, Bodil Marie Stavning

    2011-01-01

    The article analyses some of artist Søren Lose's photographic installations in which time, history and narration is reflected in the creation of allegoric, spatial relations.......The article analyses some of artist Søren Lose's photographic installations in which time, history and narration is reflected in the creation of allegoric, spatial relations....

  17. Spatial Data Supply Chains

    Science.gov (United States)

    Varadharajulu, P.; Azeem Saqiq, M.; Yu, F.; McMeekin, D. A.; West, G.; Arnold, L.; Moncrieff, S.

    2015-06-01

    This paper describes current research into the supply of spatial data to the end user in as close to real time as possible via the World Wide Web. The Spatial Data Infrastructure paradigm has been discussed since the early 1990s. The concept has evolved significantly since then but has almost always examined data from the perspective of the supplier. It has been a supplier driven focus rather than a user driven focus. The current research being conducted is making a paradigm shift and looking at the supply of spatial data as a supply chain, similar to a manufacturing supply chain in which users play a significant part. A comprehensive consultation process took place within Australia and New Zealand incorporating a large number of stakeholders. Three research projects that have arisen from this consultation process are examining Spatial Data Supply Chains within Australia and New Zealand and are discussed within this paper.

  18. A COMPARISON OF SEMANTIC SIMILARITY MODELS IN EVALUATING CONCEPT SIMILARITY

    Directory of Open Access Journals (Sweden)

    Q. X. Xu

    2012-08-01

    Full Text Available The semantic similarities are important in concept definition, recognition, categorization, interpretation, and integration. Many semantic similarity models have been established to evaluate semantic similarities of objects or/and concepts. To find out the suitability and performance of different models in evaluating concept similarities, we make a comparison of four main types of models in this paper: the geometric model, the feature model, the network model, and the transformational model. Fundamental principles and main characteristics of these models are introduced and compared firstly. Land use and land cover concepts of NLCD92 are employed as examples in the case study. The results demonstrate that correlations between these models are very high for a possible reason that all these models are designed to simulate the similarity judgement of human mind.

  19. a Comparison of Semantic Similarity Models in Evaluating Concept Similarity

    Science.gov (United States)

    Xu, Q. X.; Shi, W. Z.

    2012-08-01

    The semantic similarities are important in concept definition, recognition, categorization, interpretation, and integration. Many semantic similarity models have been established to evaluate semantic similarities of objects or/and concepts. To find out the suitability and performance of different models in evaluating concept similarities, we make a comparison of four main types of models in this paper: the geometric model, the feature model, the network model, and the transformational model. Fundamental principles and main characteristics of these models are introduced and compared firstly. Land use and land cover concepts of NLCD92 are employed as examples in the case study. The results demonstrate that correlations between these models are very high for a possible reason that all these models are designed to simulate the similarity judgement of human mind.

  20. Test plan for the soils facility demonstration: A petroleum contaminated soil bioremediation facility

    Energy Technology Data Exchange (ETDEWEB)

    Lombard, K.H.

    1994-08-01

    The objectives of this test plan are to show the value added by using bioremediation as an effective and environmentally sound method to remediate petroleum contaminated soils (PCS) by: demonstrating bioremediation as a permanent method for remediating soils contaminated with petroleum products; establishing the best operating conditions for maximizing bioremediation and minimizing volatilization for SRS PCS during different seasons; determining the minimum set of analyses and sampling frequency to allow efficient and cost-effective operation; determining best use of existing site equipment and personnel to optimize facility operations and conserve SRS resources; and as an ancillary objective, demonstrating and optimizing new and innovative analytical techniques that will lower cost, decrease time, and decrease secondary waste streams for required PCS assays.

  1. Approach of Bioremediation in Olive Oil and Dairy Industry: A Review

    Directory of Open Access Journals (Sweden)

    Amir Hamid

    2013-02-01

    Full Text Available Bioremediation methods are a promising way of dealing with soil and subsoil contamination by organic substances. This biodegradation process is supported by micro-organisms which use the organic carbon from the pollutants as energy source and cells building blocks. There are several advantages of the implementation of such methods but mainly they have to do with the lack of interference with the ecology of the ecosystem. This study presents the use of technique in numerous ways such as olive oil industry and dairy industry. Although the use of bioremediation technique is not innovative in food industry and microbiology. The use of herbicides, pesticides and contaminated chemicals are producing pollutant compounds in ecosystem which is effecting the environment. Bioremediation method is very constructive method to converted contaminated compounds into non contaminated compounds.

  2. Numerical simulations in support of the in situ bioremediation demonstration at Savannah River

    Energy Technology Data Exchange (ETDEWEB)

    Travis, B.J.; Rosenberg, N.D.

    1994-06-01

    This report assesses the performance of the in situ bioremediation technology demonstrated at the Savannah River Integrated Demonstration (SRID) site in 1992--1993. The goal of the technology demonstration was to stimulate naturally occurring methanotrophic bacteria at the SRID site with injection of methane, air and air-phase nutrients (nitrogen and phosphate) such that significant amounts of the chlorinated solvent present in the subsurface would be degraded. Our approach is based on site-specific numerical simulations using the TRAMP computer code. In this report, we discuss the interactions among the physical and biochemical processes involved in in situ bioremediation. We also investigate improvements to technology performance, make predictions regarding the performance of this technology over long periods of time and at different sites, and compare in situ bioremediation with other remediation technologies.

  3. Microorganism as a tool of bioremediation technology for cleaning environment: A review

    Directory of Open Access Journals (Sweden)

    Ravindra Singh

    2014-03-01

    Full Text Available The term bioremediation has been introduced to describe the process of using biological agents to remove toxic waste from environment. Bioremediation is the most effective management tool to manage the polluted environment and recover contaminated soil. The hazardous wastes generated from the chemical processes/operations are being treated using physico-chemical and biological methods by the respective industries to meet the prescribed standard as per the Environmental Protection Act, 1986. The wastes treated by the respective industries are collected at Common Effluent Treatment Plant, before discharge into the environment. After the treatment of collected waste at Common Effluent Treatment Plant, the solid and treated effluents are segregated and disposed of into the soil- water environment. In spite of the present treatment technology, the organic pollutants are found persisting in the soil-water environment above their acceptable level. Hence, bioremediation is an innovative technology that has the potential to alleviate the toxic contamination.

  4. Successful bioremediation of an aged and heavily contaminated soil using a microbial/plant combination strategy.

    Science.gov (United States)

    Xu, Yang; Sun, Guang-Dong; Jin, Jing-Hua; Liu, Ying; Luo, Mu; Zhong, Zhi-Ping; Liu, Zhi-Pei

    2014-01-15

    Bioremediation of an aged and heavily contaminated soil was performed using microbial remediation, phytoremediation, and microbial/phytoremediation. The removal efficiency of polycyclic aromatic hydrocarbons (PAHs) was in the order microbial/phytoremediation>microbial remediation≈phytoremediation>control. The removal percentage of microbial/phytoremediation (69.6%) was twice that of control. Kocuria sp. P10 significantly enhanced PAH removal (Psoil microbial communities were also detected by pyrosequencing. The results indicated that biodiversity of the soil bacterial community gradually increased with time and was slightly lower in control, as indicated by operational taxonomic unit (OTU) numbers and Shannon-Wiener indices. Proportions of Betaproteobacteria and Gammaproteobacteria were consistently high in all groups. Actinobacteridae were initially predominant (>37.8%) but rapidly decreased to bioremediation process and a possible basis for ecological assessment for bioremediation on a large scale.

  5. Optimalisation and feasability of bioremediation systems for the processing of spray losses of pesticides.

    Science.gov (United States)

    De Wilde, T; Spanoghe, P; Ryckeboer, J; Springael, D; Jaeken, P

    2006-01-01

    Contamination of ground and surface water puts pressure on the use of pesticides. Pesticide contamination of water can often be linked to point sources rather than to diffuse sources. Examples of such point sources are areas on farms where pesticides are handled, filled into sprayers and where sprayers are cleaned. To reduce contamination from these point sources, different kinds of bio-remediation systems are in various member states of the EU. Bioremediation is the use of living organisms, primarily micro-organisms, to degrade the environmental contaminants into less toxic forms. In this study, the behaviour of six different pesticides with varying physico-chemical properties on substrates used in a bioremediation system is studied. The adsorption of individual pesticides on the substrates is determined. After determination of the adsorption coefficient Kd, it could be concluded for metalaxyl that coco chips had the highest sorption capacity, followed by straw, compost, willow chopping and a sandy loam soil.

  6. Brevibacterium frigoritolerans as a Novel Organism for the Bioremediation of Phorate.

    Science.gov (United States)

    Jariyal, Monu; Gupta, V K; Mandal, Kousik; Jindal, Vikas

    2015-11-01

    Phorate, an organophosphorus insecticide, has been found effective for the control of various insect pests. However, it is an extremely hazardous insecticide and causes a potential threat to ecosystem. Bioremediation is a promising approach to degrade the pesticide from the soil. The screening of soil from sugarcane fields resulted in identification of Brevibacterium frigoritolerans, a microorganism with potential for phorate bioremediation was determined. B. frigoritolerans strain Imbl 2.1 resulted in the active metabolization of phorate by between 89.81% and 92.32% from soils amended with phorate at different levels (100, 200, 300 mg kg(-1) soil). But in case of control soil, 33.76%-40.92% degradation were observed. Among metabolites, sulfone was found as the main metabolite followed by sulfoxide. Total phorate residues were not found to follow the first order kinetics. This demonstrated that B. frigoritolerans has potential for bioremediation of phorate both in liquid cultures and agricultural soils.

  7. Applicability and Limits of Bioremediation of Contaminated Groundwater by Organic Compounds

    Institute of Scientific and Technical Information of China (English)

    Taboure Aboubacar; Lin Xueyu

    2001-01-01

    This paper gives in some ways a broad look at the Bioremediation Technology in the treatment of polluted groundwater. Environmentalists and Hydrologeologists around the world, especially in the developed countries welcomed this revolutionizing technique at a moment when other methods were becoming rather expensive and sources of secondary and more challenging pollution problems across sole fresh groundwater. Bioremediation of contaminated groundwater is based on the use of bacteria which breakdown organic matters to more stable forms, which will not create nuisance or give off foul odors. The Applicability of this technology at a specific site lies in the understanding of the site's hydrogeologic, physiochemical backgrounds and the knowledge of the properties of the designated bacteria colonies, which would likely stabilize the contaminants. These are key points, which determine the success of the all process. Only, by complying with all those measures, Bioremediation can meet all the expectations.

  8. Ex-situ bioremediation of Brazilian soil contaminated with plasticizers process wastes

    Directory of Open Access Journals (Sweden)

    I. D. Ferreira

    2012-03-01

    Full Text Available The aim of this research was to evaluate the bioremediation of a soil contaminated with wastes from a plasticizers industry, located in São Paulo, Brazil. A 100-kg soil sample containing alcohols, adipates and phthalates was treated in an aerobic slurry-phase reactor using indigenous and acclimated microorganisms from the sludge of a wastewater treatment plant of the plasticizers industry (11gVSS kg-1 dry soil, during 120 days. The soil pH and temperature were not corrected during bioremediation; soil humidity was corrected weekly to maintain 40%. The biodegradation of the pollutants followed first-order kinetics; the removal efficiencies were above 61% and, among the analyzed plasticizers, adipate was removed to below the detection limit. Biological molecular analysis during bioremediation revealed a significant change in the dominant populations initially present in the reactor.

  9. ASSESSMENT OF DISTILLERY EFFLUENT IRRIGATION ON SOIL MICROBES AND ITS BIOREMEDIATION

    Directory of Open Access Journals (Sweden)

    Tripathi D. M

    2014-12-01

    Full Text Available The present study deals with the assessment of toxicity of distillery effluent on soil microorganisms and its quality improvement through bioremediation using Pseudomonas spp. Under lab scale experiment, different dilutions of distillery effluent i.e. 25%, 50%, 75% were used to examine effects on physico-chemical parameters of effluent and on soil microflora e.g. algae, bacteria, fungi and actinomycetes. The results revealed that dilution may reduce significantly the metal contents and other toxicants in the effluent as well as in the soil. Statistical analysis revealed that bioremediation of distillery effluent using Pseudomonas spp. caused significant reduction in BOD, COD, TDS, TN, TP and color. The study indicates that raw distillery effluent is harmful for soil microflora and bioremediation improves the quality of distillery effluent making it suitable as a soil amendment.

  10. Dynamism of PGPR in bioremediation and plant growth promotion in heavy metal contaminated soil.

    Science.gov (United States)

    Patel, P R; Shaikh, S S; Sayyed, R Z

    2016-04-01

    Heavy metal contamination, particularly of cultivable lands, is a matter of concern. Bioremediation helps in reversing such contamination to certain extent. Here, we report isolation, polyphasic identification and the role of siderophore producing rhizobacteria Alcaligenes feacalis RZS2 and Pseudomonas aeruginosa RZS3 in bioremediation of heavy metal contaminated soil and plant growth promotion activity in such contaminated soil. Siderophore produced by A. feacalis RZS2 and P. aeruginosa RZS3 strains chelated various heavy metal ions like MnCl₂.4H₂O, NiCl₂.6H₂O, ZnCl₂, CuCl₂ and CoCl₂ other than FeCl₃.6H2O at batch scale. Their bioremediation potential was superior over the chemical ion chelators like EDTA and citric acid. These isolates also promoted growth of wheat and peanut seeds sown in heavy metal contaminated soil. Effective root colonizing ability of these isolates was observed in wheat and peanut plants.

  11. Renewing the Respect for Similarity

    Directory of Open Access Journals (Sweden)

    Shimon eEdelman

    2012-07-01

    Full Text Available In psychology, the concept of similarity has traditionally evoked a mixture of respect, stemmingfrom its ubiquity and intuitive appeal, and concern, due to its dependence on the framing of the problemat hand and on its context. We argue for a renewed focus on similarity as an explanatory concept, bysurveying established results and new developments in the theory and methods of similarity-preservingassociative lookup and dimensionality reduction — critical components of many cognitive functions, aswell as of intelligent data management in computer vision. We focus in particular on the growing familyof algorithms that support associative memory by performing hashing that respects local similarity, andon the uses of similarity in representing structured objects and scenes. Insofar as these similarity-basedideas and methods are useful in cognitive modeling and in AI applications, they should be included inthe core conceptual toolkit of computational neuroscience.

  12. A synthesis of similarity and eddy-viscosity models

    NARCIS (Netherlands)

    Verstappen, R.; Friedrich, R; Geurts, BJ; Metais, O

    2004-01-01

    In large-eddy simulation, a low-pass spatial filter is usually applied to the Navier-Stokes equations. The resulting commutator of the filter and the nonlinear term is usually modelled by an eddy-viscosity model, by a similarity model or by a mix thereof. Similarity models possess the proper mathema

  13. Similarity Learning of Manifold Data.

    Science.gov (United States)

    Chen, Si-Bao; Ding, Chris H Q; Luo, Bin

    2015-09-01

    Without constructing adjacency graph for neighborhood, we propose a method to learn similarity among sample points of manifold in Laplacian embedding (LE) based on adding constraints of linear reconstruction and least absolute shrinkage and selection operator type minimization. Two algorithms and corresponding analyses are presented to learn similarity for mix-signed and nonnegative data respectively. The similarity learning method is further extended to kernel spaces. The experiments on both synthetic and real world benchmark data sets demonstrate that the proposed LE with new similarity has better visualization and achieves higher accuracy in classification.

  14. Large Scale Bioremediation of Petroleum Hydrocarbon Contaminated Waste at Various Installations of ONGC. India: Case Studies

    Directory of Open Access Journals (Sweden)

    Ajoy Kumar Mandal

    2014-07-01

    Full Text Available In situ and ex situ bioremediation of oil contaminated effluent pits, sludge pits, oil spilled land and tank bottom, and effluent treatment plant (ETP oily sludge was carried out at Ankleshwar, Mehsana, Assam and Cauvery Asset of Oil and Natural Gas Corporation Limited (ONGC, India. The types of contaminant were heavy paraffinic, asphaltic and light crude oil and emulsified oily sludge /contaminated soil. An indigenous microbial consortium was developed by assembling four species of bacteria, isolated from various oil contaminated sites of India, which could biodegrade different fractions of total petroleum hydrocarbon (TPH of the oily waste to environment friendly end products. The said consortium was on a large scale field applied to the above oil installations and it successfully bioremediated 30,706 tonnes of different types of oily waste. In 65 case studies of different batch size of in situ and ex situ bioremediation processes, the initial TPH content varying from 69.20 to 662.70 g/kg of oily waste has been biodegraded to 5.30 – 16.90 g/kg of oily waste in a range of 2 to 33 months. Biodegradation rate varied in the range of 0.22 – 1.10 Kg TPH /day/m2 area due to the climatic condition of the treatment zone and the type of waste treated. The bioremediated soil was non-toxic and natural vegetation was found to be grown on the same ground. Successful eco-restoration of one large effluent pit of 26,000 m2 area was carried out by cultivation of local fish species after completion of bioremediation. Bioremediation technology has helped ONGC with the management of their hazardous oily wastes in an environment friendly manner. DOI: http://dx.doi.org/10.5755/j01.erem.68.2.5632

  15. Ecotoxicological evaluation of diesel-contaminated soil before and after a bioremediation process.

    Science.gov (United States)

    Molina-Barahona, L; Vega-Loyo, L; Guerrero, M; Ramírez, S; Romero, I; Vega-Jarquín, C; Albores, A

    2005-02-01

    Evaluation of contaminated sites is usually performed by chemical analysis of pollutants in soil. This is not enough either to evaluate the environmental risk of contaminated soil nor to evaluate the efficiency of soil cleanup techniques. Information on the bioavailability of complex mixtures of xenobiotics and degradation products cannot be totally provided by chemical analytical data, but results from bioassays can integrate the effects of pollutants in complex mixtures. In the preservation of human health and environment quality, it is important to assess the ecotoxicological effects of contaminated soils to obtain a better evaluation of the healthiness of this system. The monitoring of a diesel-contaminated soil and the evaluation of a bioremediation technique conducted on a microcosm scale were performed by a battery of ecotoxicological tests including phytotoxicity, Daphnia magna, and nematode assays. In this study we biostimulated the native microflora of soil contaminated with diesel by adding nutrients and crop residue (corn straw) as a bulking agent and as a source of microorganisms and nutrients; in addition, moisture was adjusted to enhance diesel removal. The bioremediation process efficiency was evaluated directly by an innovative, simple phytotoxicity test system and the diesel extracts by Daphnia magna and nematode assays. Contaminated soil samples were revealed to have toxic effects on seed germination, seedling growth, and Daphnia survival. After biostimulation, the diesel concentration was reduced by 50.6%, and the soil samples showed a significant reduction in phytotoxicity (9%-15%) and Daphnia assays (3-fold), confirming the effectiveness of the bioremediation process. Results from our microcosm study suggest that in addition to the evaluation of the bioremediation processes efficiency, toxicity testing is different with organisms representative of diverse phylogenic levels. The integration of analytical, toxicological and bioremediation data

  16. Control of petroleum-hydrocarbon contaminated groundwater by intrinsic and enhanced bioremediation.

    Science.gov (United States)

    Chen, Ku-Fan; Kao, Chih-Ming; Chen, Chiu-Wen; Surampalli, Rao Y; Lee, Mu-Sheng

    2010-01-01

    In the first phase of this study, the effectiveness of intrinsic bioremediation on the containment of petroleum hydrocarbons was evaluated at a gasoline spill site. Evidences of the occurrence of intrinsic bioremediation within the BTEX (benzene, toluene, ethylbenzene, and xylenes) plume included (1) decreased BTEX concentrations; (2) depletion of dissolved oxygen (DO), nitrate, and sulfate; (3) production of dissolved ferrous iron, methane, and CO2; (4) deceased pH and redox potential; and (5) increased methanogens, total heterotrophs, and total anaerobes, especially within the highly contaminated areas. In the second phase of this study, enhanced aerobic bioremediation process was applied at site to enhance the BTEX decay rates. Air was injected into the subsurface near the mid-plume area to biostimulate the naturally occurring microorganisms for BTEX biodegradation. Field results showed that enhanced bioremediation process caused the change of BTEX removal mechanisms from anaerobic biodegradation inside the plume to aerobic biodegradation. This variation could be confirmed by the following field observations inside the plume due to the enhanced aerobic bioremediation process: (1) increased in DO, CO2, redox potential, nitrate, and sulfate, (2) decreased in dissolved ferrous iron, sulfide, and methane, (3) increased total heterotrophs and decreased total anaerobes. Field results also showed that the percentage of total BTEX removal increased from 92% to 99%, and the calculated total BTEX first-order natural attenuation rates increased from 0.0092% to 0.0188% per day, respectively, after the application of enhanced bioremediation system from the spill area to the downgradient area (located approximately 300 m from the source area).

  17. Non-Metric Similarity Measures

    Science.gov (United States)

    2015-03-26

    are numeric. Out of 11 data sets used, six are from text mining domain, two from music classification and retrieval domain, 2 from character...algorithm for discovering clusters in large spatial databases with noise . Proceed- ings of ACM SIGKDD Conference on Knowledge Discovery and Data

  18. The sequential application of macroalgal biosorbents for the bioremediation of a complex industrial effluent.

    Directory of Open Access Journals (Sweden)

    Joel T Kidgell

    Full Text Available Fe-treated biochar and raw biochar produced from macroalgae are effective biosorbents of metalloids and metals, respectively. However, the treatment of complex effluents that contain both metalloid and metal contaminants presents a challenging scenario. We test a multiple-biosorbent approach to bioremediation using Fe-biochar and biochar to remediate both metalloids and metals from the effluent from a coal-fired power station. First, a model was derived from published data for this effluent to predict the biosorption of 21 elements by Fe-biochar and biochar. The modelled outputs were then used to design biosorption experiments using Fe-biochar and biochar, both simultaneously and in sequence, to treat effluent containing multiple contaminants in excess of water quality criteria. The waste water was produced during ash disposal at an Australian coal-fired power station. The application of Fe-biochar and biochar, either simultaneously or sequentially, resulted in a more comprehensive remediation of metalloids and metals compared to either biosorbent used individually. The most effective treatment was the sequential use of Fe-biochar to remove metalloids from the waste water, followed by biochar to remove metals. Al, Cd, Cr, Cu, Mn, Ni, Pb, Zn were reduced to the lowest concentration following the sequential application of the two biosorbents, and their final concentrations were predicted by the model. Overall, 17 of the 21 elements measured were remediated to, or below, the concentrations that were predicted by the model. Both metalloids and metals can be remediated from complex effluent using biosorbents with different characteristics but derived from a single feedstock. Furthermore, the extent of remediation can be predicted for similar effluents using additive models.

  19. The sequential application of macroalgal biosorbents for the bioremediation of a complex industrial effluent.

    Science.gov (United States)

    Kidgell, Joel T; de Nys, Rocky; Paul, Nicholas A; Roberts, David A

    2014-01-01

    Fe-treated biochar and raw biochar produced from macroalgae are effective biosorbents of metalloids and metals, respectively. However, the treatment of complex effluents that contain both metalloid and metal contaminants presents a challenging scenario. We test a multiple-biosorbent approach to bioremediation using Fe-biochar and biochar to remediate both metalloids and metals from the effluent from a coal-fired power station. First, a model was derived from published data for this effluent to predict the biosorption of 21 elements by Fe-biochar and biochar. The modelled outputs were then used to design biosorption experiments using Fe-biochar and biochar, both simultaneously and in sequence, to treat effluent containing multiple contaminants in excess of water quality criteria. The waste water was produced during ash disposal at an Australian coal-fired power station. The application of Fe-biochar and biochar, either simultaneously or sequentially, resulted in a more comprehensive remediation of metalloids and metals compared to either biosorbent used individually. The most effective treatment was the sequential use of Fe-biochar to remove metalloids from the waste water, followed by biochar to remove metals. Al, Cd, Cr, Cu, Mn, Ni, Pb, Zn were reduced to the lowest concentration following the sequential application of the two biosorbents, and their final concentrations were predicted by the model. Overall, 17 of the 21 elements measured were remediated to, or below, the concentrations that were predicted by the model. Both metalloids and metals can be remediated from complex effluent using biosorbents with different characteristics but derived from a single feedstock. Furthermore, the extent of remediation can be predicted for similar effluents using additive models.

  20. Functional environmental proteomics: elucidating the role of a c-type cytochrome abundant during uranium bioremediation.

    Science.gov (United States)

    Yun, Jiae; Malvankar, Nikhil S; Ueki, Toshiyuki; Lovley, Derek R

    2016-02-01

    Studies with pure cultures of dissimilatory metal-reducing microorganisms have demonstrated that outer-surface c-type cytochromes are important electron transfer agents for the reduction of metals, but previous environmental proteomic studies have typically not recovered cytochrome sequences from subsurface environments in which metal reduction is important. Gel-separation, heme-staining and mass spectrometry of proteins in groundwater from in situ uranium bioremediation experiments identified a putative c-type cytochrome, designated Geobacter subsurface c-type cytochrome A (GscA), encoded within the genome of strain M18, a Geobacter isolate previously recovered from the site. Homologs of GscA were identified in the genomes of other Geobacter isolates in the phylogenetic cluster known as subsurface clade 1, which predominates in a diversity of Fe(III)-reducing subsurface environments. Most of the gscA sequences recovered from groundwater genomic DNA clustered in a tight phylogenetic group closely related to strain M18. GscA was most abundant in groundwater samples in which Geobacter sp. predominated. Expression of gscA in a strain of Geobacter sulfurreducens that lacked the gene for the c-type cytochrome OmcS, thought to facilitate electron transfer from conductive pili to Fe(III) oxide, restored the capacity for Fe(III) oxide reduction. Atomic force microscopy provided evidence that GscA was associated with the pili. These results demonstrate that a c-type cytochrome with an apparent function similar to that of OmcS is abundant when Geobacter sp. are abundant in the subsurface, providing insight into the mechanisms for the growth of subsurface Geobacter sp. on Fe(III) oxide and suggesting an approach for functional analysis of other Geobacter proteins found in the subsurface.

  1. Composition and pathogenic potential of a microbial bioremediation product used for crude oil degradation

    Science.gov (United States)

    Tayabali, Azam F.; Coleman, Gordon; Crosthwait, Jennifer; Nguyen, Kathy C.; Zhang, Yan; Shwed, Philip

    2017-01-01

    A microbial bioremediation product (MBP) used for large-scale oil degradation was investigated for microbial constituents and possible pathogenicity. Aerobic growth on various media yielded >108 colonies mL-1. Full-length 16S rDNA sequencing and fatty acid profiling from morphologically distinct colonies revealed ≥13 distinct genera. Full-length 16S rDNA library sequencing, by either Sanger or long-read PacBio technology, suggested that up to 21% of the MBP was composed of Arcobacter. Other high abundance microbial constituents (>6%) included the genera Proteus, Enterococcus, Dysgonomonas and several genera in the order Bacteroidales. The MBP was most susceptible to ciprofloxacin, doxycycline, gentamicin, and meropenam. MBP exposure of human HT29 and A549 cells caused significant cytotoxicity, and bacterial growth and adherence. An acellular MBP filtrate was also cytotoxic to HT29, but not A549. Both MBP and filtrate exposures elevated the neutrophil chemoattractant IL-8. In endotracheal murine exposures, bacterial pulmonary clearance was complete after one-week. Elevation of pro-inflammatory cytokines IL-1β, IL-6, and TNF-α, and chemokines KC and MCP-1 occurred between 2h and 48h post-exposure, followed by restoration to baseline levels at 96h. Cytokine/chemokine signalling was accompanied by elevated blood neutrophils and monocytes at 4h and 48h, respectively. Peripheral acute phase response markers were maximal at 24h. All indicators examined returned to baseline values by 168h. In contrast to HT29, but similar to A549 observations, MBP filtrate did not induce significant murine effects with the indicators examined. The results demonstrated the potentially complex nature of MBPs and transient immunological effects during exposure. Products containing microbes should be scrutinized for pathogenic components and subjected to characterisation and quality validation prior to commercial release. PMID:28178315

  2. Comparison of feeding strategies in acute toxicity tests of crude oil and commercial bioremediation agents

    Energy Technology Data Exchange (ETDEWEB)

    Cavender, R.C.; Cherry, D.S.; Yeager, M.M. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Biology Dept.; Bidwell, J.R. [Univ. of South Australia, Adelaide (Australia). School of Pharmacy and Medical Sciences

    1995-12-31

    Proposed modifications to the National Oil and Hazardous Substance Pollution Contingency Plan have prompted examinations of the methodology used in toxicity testing of the water soluble fraction (WSF) of oil, commercial bioremediation agents (CBA), and a combination of the two. The organisms currently used in acute (96 hr) testing of these agents are the inland silverside, Menidia beryllina, and an estuarine mysid, Mysidopsis bahia. The mysid is a carnivorous species that must be fed during a test in order to prevent predation within the test chambers. Currently proposed methodology for silverside testing also includes feeding. The high oxygen demand of CBAs and the WSF of oil causes dissolved oxygen to be a factor in toxicity. This effect can be intensified by the addition of brine shrimp (Artemia sp.) to the test chambers. The purpose of this study was to compare the toxicity of CBAs in combination with the WSF of oil to silversides with and without the addition of food. Tests were conducted using both 24-hour and 14-day spinning times for the CBA/WSF mixture. With the 24-hour spinning time, LC50 values from each day of the 4-day test were consistently lower in the Artemia fed test (47.8--22.6%) as compared to the unfed test (72.1--43.0%). A similar trend was seen in the 24 and 48 hour LC50`s in the 14-day spinning time. Overall, low dissolved oxygen was found to be most relevant at the highest CBA/WSF concentrations where D.O. dropped below 2 mg/l in Artemia fed tests.

  3. Characterization and Transcription of Arsenic Respiration and Resistance Genes During In Situ Uranium Bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Giloteaux, L.; Holmes, Dawn E.; Williams, Kenneth H.; Wrighton, Kelly C.; Wilkins, Michael J.; Montgomery, Alison P.; Smith, Jessica A.; Orellana, Roberto; Thompson, Courtney A.; Roper, Thomas J.; Long, Philip E.; Lovley, Derek R.

    2013-02-04

    The possibility of arsenic release and the potential role of Geobacter in arsenic biogeochemistry during in situ uranium bioremediation was investigated because increased availability of organic matter has been associated with substantial releases of arsenic in other subsurface environments. In a field experiment conducted at the Rifle, CO study site, groundwater arsenic concentrations increased when acetate was added. The number of transcripts from arrA, which codes for the alpha subunit of dissimilatory As(V) reductase, and acr3, which codes for the arsenic pump protein Acr3, were determined with quantitative RT-PCR. Most of the arrA (> 60%) and acr3-1 (> 90%) sequences that were recovered were most similar to Geobacter species, while the majority of acr3-2 (>50%) sequences were most closely related to Rhodoferax ferrireducens. Analysis of transcript abundance demonstrated that transcription of acr3-1 by the subsurface Geobacter community was correlated with arsenic concentrations in the groundwater. In contrast, Geobacter arrA transcript numbers lagged behind the major arsenic release and remained high even after arsenic concentrations declined. This suggested that factors other than As(V) availability regulated transcription of arrA in situ even though the presence of As(V) increased transcription of arrA in cultures of G. lovleyi, which was capable of As(V) reduction. These results demonstrate that subsurface Geobacter species can tightly regulate their physiological response to changes in groundwater arsenic concentrations. The transcriptomic approach developed here should be useful for the study of a diversity of other environments in which Geobacter species are considered to have an important influence on arsenic biogeochemistry.

  4. Compost as a source of microbial isolates for the bioremediation of heavy metals: In vitro selection

    Energy Technology Data Exchange (ETDEWEB)

    Vargas-Garcia, Maria del Carmen, E-mail: mcvargas@ual.es; Lopez, Maria Jose, E-mail: mllopez@ual.es; Suarez-Estrella, Francisca, E-mail: fsuarez@ual.es; Moreno, Joaquin, E-mail: jcasco@ual.es

    2012-08-01

    Heavy metal pollution has become a major environmental concern nowadays and the bioremediation of polluted habitats is an increasingly popular strategy due to both its efficiency and safety. A screening and selection protocol based on different composting processes was designed in order to isolate heavy metal-resistant microorganisms. A collection of 51 microorganisms was obtained and most of them showed the capability to tolerate heavy metals in multi-polluted aqueous systems (Cd(II), Cr(VI), Ni, Pb, Zn(II)), as well as to remove them. The highest detoxification ratios were observed for Pb. Some of the isolates detoxifying more than a 90% of this metal, while the other metals were removed in a range between 20% and 60%. The best isolates (Graphium putredinis, Fusarium solani, Fusarium sp. and Penicillium chrysogenum) were further assayed in order to determine the predominant removal mechanism and the potential use of their dead biomass as a biosorbent. Intracellular accumulation was the prevalent mechanism for most isolates and metals, with the exception of Ni. In this case, the proportion removed by extracellular adsorption was similar or even higher than that removed by intracellular accumulation. Thus, the efficiency of living cells was higher than that of dead biomass except in the case of Ni. - Highlights: Black-Right-Pointing-Pointer Composting is a good reservoir for the isolation of HM-resistant microorganisms. Black-Right-Pointing-Pointer Pb was the most removed heavy metal in multi-polluted aqueous systems. Black-Right-Pointing-Pointer Intracellular accumulation was the predominant mechanism for heavy metal removal. Black-Right-Pointing-Pointer Graphium putredinis, which detoxifies organic pollutants, was the most efficient isolate.

  5. Bioremediation of soils contaminated by hydrocarbons at the coastal zone of “Punta Majagua”.

    OpenAIRE

    Jelvys Bermúdez Acosta; Roberto Núñez Moreira; Yoelvis Castro Hernández

    2012-01-01

    The purpose of this research was to describe and assess the main results in the process of bioremediation of 479 m3 of petroleum residuals spilled on the soil and restrained into four deposits of fuel on the coastal zone of “Punta Majagua”, Cienfuegos. The volume of hydrocarbons spilled and contained into the tanks was determined by means of their previous mixture with fertile ground in a ratio of 3/1. The hydrocarbons were disposed in a bioremediation area of 115 m X 75m built in situ. In tu...

  6. Bioremediation of the organochlorine pesticides, dieldrin and endrin, and their occurrence in the environment.

    Science.gov (United States)

    Matsumoto, Emiko; Kawanaka, Youhei; Yun, Sun-Ja; Oyaizu, Hiroshi

    2009-08-01

    Dieldrin and endrin are persistent organic pollutants that cause serious environmental problems. Although these compounds have been prohibited over the past decades in most countries around the world, they are still routinely found in the environment, especially in the soil in agricultural fields. Bioremediation, including phytoremediation and rhizoremediation, is expected to be a useful cleanup method for this soil contamination. This review provides an overview of the environmental contamination by dieldrin and endrin, along with a summary of our current understanding and recent advances in bioremediation and phytoremediation of these pollutants. In particular, this review focuses on the types and abilities of plants and microorganisms available for accumulating and degrading dieldrin and endrin.

  7. Is it possible to increase bioavailability but not environmental risk of PAHs in bioremediation?

    Science.gov (United States)

    Ortega-Calvo, J J; Tejeda-Agredano, M C; Jimenez-Sanchez, C; Congiu, E; Sungthong, R; Niqui-Arroyo, J L; Cantos, M

    2013-10-15

    The current poor predictability of end points associated with the bioremediation of polycyclic aromatic hydrocarbons (PAHs) is a large limitation when evaluating its viability for treating contaminated soils and sediments. However, we have seen a wide range of innovations in recent years, such as an the improved use of surfactants, the chemotactic mobilization of bacterial inoculants, the selective biostimulation at pollutant interfaces, rhizoremediation and electrobioremediation, which increase the bioavailability of PAHs but do not necessarily increase the risk to the environment. The integration of these strategies into practical remediation protocols would be beneficial to the bioremediation industry, as well as improve the quality of the environment.

  8. Immobilized Native Bacteria as a Tool for Bioremediation of Soils and Waters: Implementation and Modeling

    Directory of Open Access Journals (Sweden)

    C. Lobo

    2002-01-01

    Full Text Available Based on 3,4-dihydroxyphenylacetate (3,4-DHPA dioxygenase amino acid sequence and DNA sequence data for homologous genes, two different oligonucleotides were designed. These were assayed to detect 3,4-DHPA related aromatic compound—degrading bacteria in soil samples by using the FISH method. Also, amplification by PCR using a set of ERIC primers was assayed for the detection of Pseudomonas GCH1 strain, which used in the soil bioremediation process. A model was developed to understand and predict the behavior of bacteria and pollutants in a bioremediation system, taking into account fluid dynamics, molecular/cellular scale processes, and biofilm formation.

  9. Dynamic similarity in erosional processes

    Science.gov (United States)

    Scheidegger, A.E.

    1963-01-01

    A study is made of the dynamic similarity conditions obtaining in a variety of erosional processes. The pertinent equations for each type of process are written in dimensionless form; the similarity conditions can then easily be deduced. The processes treated are: raindrop action, slope evolution and river erosion. ?? 1963 Istituto Geofisico Italiano.

  10. Optimization of a Hydrocarbon Bioremediation System at Laboratory Scale

    Directory of Open Access Journals (Sweden)

    Acuña A.J.

    2012-01-01

    Full Text Available The aim of this study was to optimize the parameters of moisture, temperature and ratio of nutrients to estimate the possibility of applying the technique of bioremediation in a soil contaminated with hydrocarbons. For this, an initial characterization of contaminated soil was made according to their physical and chemical characteristics and the number of heterotrophic and hydrocarbon degraders bacteria. Also the contaminant concentration by gravimetric method and by gas chromatography was studied. To optimize moisture and temperature, microcosms with moisture of 3%, 10%, 15% and 20% and temperatures of 5°C, 15°C, 28°C and 37°C were used. The monitoring of the mineralization of hydrocarbons was performed by measuring the CO2 produced. To optimize the ratio of nutrients, different microcosms were designed and were monitored by oxygen consumption and by determination of hydrocarbons by gas chromatography. The C:N:P relationships studied were 100:20:2, 100:10:1, 100:5:0,5 and 100:1:0,1. The results indicate that the mineralization of hydrocarbons was optimal for moisture of 10% to 20% and temperatures of 25°C to 37°C with CO2 production values of 3000-4500 mgCO2 kg-1. The optimal C:N:P ratio was 100:1:0,1 in which the highest oxygen consumption was and the elimination of 83% of total hydrocarbons determined by gas chromatography with 78% and 89% of n-alkanes and polyaromatic hydrocarbons elimination, respectively.

  11. Fine tuning soil nitrogen to maximize petroleum bioremediation

    Energy Technology Data Exchange (ETDEWEB)

    Walworth, J.; Pond, A. [Arizona Univ., Tucson, AZ (United States); Snape, I.; Rayner, J.; Ferguson, S.; Harvey, P. [Australian Antarctic Division, Kingston, Tasmania (Australia)

    2005-07-01

    Although many studies indicate positive effects from the application of nitrogen to support bioremediation, a surprisingly large number report no benefit, or even deleterious effects when excessive levels of nitrogen are applied. Inhibitory effects include an increased lag phase and preferential inhibition of aromatic degradation. Microbial inhibition has been reported at lower application rates. In this study, oil was collected from a petroleum contaminated site on Macquarie Island, Australia, where the Australian Antarctic Division has maintained a permanent station since 1948. The soil used in this study was collected from a site where an overflow of fuel was reported in 1975. Soil was placed in glass bottles and brought to the University of Arizona. Petroleum hydrocarbons were extracted from 10 g samples of soil with 10 ml of hexane, and 0.5 ml of an internal standard solution. Sieve analysis included: nitrogen levels; water potential depression resulting from the addition of inorganic nitrogen fertilizer; and oxygen consumption during incubation of petroleum contaminated soil. Oxygen (O{sub 2}) consumption was monitored with an N-Con respirometer for approximately 4 months. Maximum O{sub 2} uptake was observed with 125 and 250 mg nitrogen/kg of soil application rates. Respiration in the 625 mg/kg treatment was slightly lower than that in the untreated soil, although they were statistically identical. The nitrogen application rate related to microbial inhibition was lower than in previous studies. Results suggested that a reasonable cutoff level for added plus native inorganic soil nitrogen should be approximately 1,800 mg of nitrogen per kg of soil in water, a lower value than previously recommended. It appeared that this level was applicable without regard to soil salinity. Use of sparingly soluble nitrogen sources may permit the addition of higher nitrogen doses by minimizing osmotic stress. Additionally, nitrogen applications can be split into multiple

  12. MICROBIAL TRANSFORMATIONS OF RADIONUCLIDES AND ENVIRONMENTAL RESTORATION THROUGH BIOREMEDIATION.

    Energy Technology Data Exchange (ETDEWEB)

    FRANCIS, A.J.

    2006-09-29

    Treatment of waste streams containing radionuclides, the remediation of contaminated materials, soils, and water, and the safe and economical disposal of radionuclides and toxic metals containing wastes is a major concern. Radionuclides may exist in various oxidation states and may be present as oxide, coprecipitates, inorganic, and organic complexes depending on the process and waste stream. Unlike organic contaminants, the metals cannot be destroyed, but must either be converted to a stable form or removed. Microorganisms present in the natural environment play a major role in the mobilization and immobilization of radionuclides and toxic metals by direct enzymatic or indirect non-enzymatic actions and could affect the chemical nature of the radionuclides by altering the speciation, solubility and sorption properties and thus could increase or decrease the concentrations of radionuclides in solution. Fundamental understanding of the mechanisms of microbiological transformations of various chemical forms of uranium present in wastes and contaminated soils and water has led to the development of novel bioremediation processes. One process uses anaerobic bacteria to stabilize the radionuclides by reductive precipitation from higher to lower oxidation state with a concurrent reduction in volume due to the dissolution and removal of nontoxic elements from the waste matrix. In an another process, uranium and other toxic metals are removed from contaminated surfaces, soils, and wastes by extracting with the chelating agent citric acid. Uranium is recovered from the citric acid extract after biodegradation followed by photodegradation in a concentrated form as UO{sub 3} {center_dot} 2H{sub 2}O for recycling or appropriate disposal. These processes use all naturally occurring materials, common soil bacteria, naturally occurring organic compound citric acid and sunlight.

  13. Recent advances in the bioremediation of arsenic-contaminated groundwater.

    Science.gov (United States)

    Zouboulis, Anastasios I; Katsoyiannis, Ioannis A

    2005-02-01

    The biological treatment of groundwater is used primarily to remove electron donors from water sources, providing (biologically) stable drinking water, which preclude bacterial regrowth during subsequent water distribution. To the electron donors belong also the dissolved metal cations of ferrous iron and manganese, which are common contaminants found in most (anaerobic) groundwater. The removal of iron and manganese is usually accomplished by the application of chemical oxidation and filtration. However, biological oxidation has recently gained increased importance and application due to the existence of certain advantages, over the conventional physicochemical treatment. The oxidation of iron and manganese is accelerated by the presence of certain indigenous bacteria, the so-called "iron and manganese oxidizing bacteria." In the present paper, selected long-term experimental results will be presented, regarding the bioremediation of natural groundwater, containing elevated concentrations of iron and arsenic. Arsenic is considered as a primary pollutant in drinking water due to its high toxicity. Therefore, its efficient removal from natural waters intended for drinking water is considered of great importance. The application of biological processes for the oxidation and removal of dissolved iron was found to be an efficient treatment technique for the simultaneous removal of arsenic, from initial concentrations between 60 and 80 microg/l to residual (effluent) arsenic concentrations lower than the limit of 10 microg/l. The paper was focused on the removal of As(III) as the most common species in anaerobic groundwater and generally is removed less efficiently than the oxidized form of As(V). To obtain information for the mechanism of As(III) removal, X-ray photoelectron spectroscopy (XPS) analyses were applied and it was found that As(III) was partially oxidized to As(V), which enabled the high arsenic removal efficiency over a treatment period of 10 months.

  14. Bioremediation of a Large Chlorinated Solvent Plume, Dover AFB, DE

    Energy Technology Data Exchange (ETDEWEB)

    Bloom, Aleisa C [ORNL

    2015-01-01

    Bioremediation of a Large Chlorinated Solvent Plume, Dover AFB, DE Aleisa Bloom, (Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA) Robert Lyon (bob.lyon@aecom.com), Laurie Stenberg, and Holly Brown (AECOM, Germantown, Maryland, USA) ABSTRACT: Past disposal practices at Dover Air Force Base (AFB), Delaware, created a large solvent plume called Area 6 (about 1 mile long, 2,000 feet wide, and 345 acres). The main contaminants are PCE, TCE, and their degradation products. The remedy is in-situ accelerated anaerobic bioremediation (AAB). AAB started in 2006 and is focusing on source areas and downgradient plume cores. Direct-push injections occurred in source areas where contamination is typically between 5 and 20 feet below ground surface. Lower concentration dissolved-phased contamination is present downgradient at 35 and 50 feet below ground surface. Here, permanent injection/extraction wells installed in transects perpendicular to the flow of groundwater are used to apply AAB. The AAB substrate is a mix of sodium lactate, emulsified vegetable oil, and nutrients. After eight years, dissolved contaminant mass within the main 80-acre treatment area has been reduced by over 98 percent. This successful application of AAB has stopped the flux of contaminants to the more distal portions of the plume. While more time is needed for effects to be seen in the distal plume, AAB injections will soon cease, and the remedy will transition to natural attenuation. INTRODUCTION Oak Ridge National Laboratory Environmental Science Division (ORNL) and AECOM (formerly URS Corporation) have successfully implemented in situ accelerated anaerobic bioremediation (AAB) to remediate chlorinated solvent contamination in a large, multi-sourced groundwater plume at Dover Air Force Base (AFB). AAB has resulted in significant reductions of dissolved phase chlorinated solvent concentrations. This plume, called Area 6, was originally over 1 mile in length and over 2,000 feet wide (Figure 1

  15. Similarity and scale in catchment storm response

    Science.gov (United States)

    Wood, Eric F.; Sivapalan, Murugesu; Beven, Keith

    1993-01-01

    Until recently, very little progress had been made in understanding the relationship between small-scale variability of topography, soil, and rainfalls and the storm response seen at the catchment scale. The work reviewed here represents the first attempt at a systematic theoretical framework for such understanding in the context of surface runoff generation by different processes. The parameterization of hydrological processes over a range of scales is examined, and the concept of the 'representative elementary area' (REA) is introduced. The REA is a fundamental scale for catchment modeling at which continuum assumptions can be applied for the spatially variable controls and parameters, and spatial patterns no longer have to be considered explicitly. The investigation of scale leads into the concept of hydrologic similarity in which the effects of the environmental controls on runoff generation and flood frequency response be investigated independently of catchment scale. The paper reviews the authors' initial results and hopefully will motivate others to also investigate the issues of hydrologic scale and similarity.

  16. Similarity of samples and trimming

    CERN Document Server

    Álvarez-Esteban, Pedro C; Cuesta-Albertos, Juan A; Matrán, Carlos; 10.3150/11-BEJ351

    2012-01-01

    We say that two probabilities are similar at level $\\alpha$ if they are contaminated versions (up to an $\\alpha$ fraction) of the same common probability. We show how this model is related to minimal distances between sets of trimmed probabilities. Empirical versions turn out to present an overfitting effect in the sense that trimming beyond the similarity level results in trimmed samples that are closer than expected to each other. We show how this can be combined with a bootstrap approach to assess similarity from two data samples.

  17. Developments in Bioremediation of Soils and Sediments Polluted with Metals and Radionuclides: 2. Field Research on Bioremediation of Metals and Radionuclides

    OpenAIRE

    Hazen, Terry C.

    2010-01-01

    Bioremediation of metals and radionuclides has had many field tests, demonstrations, and full-scale implementations in recent years. Field research in this area has occurred for many different metals and radionuclides using a wide array of strategies. These strategies can be generally characterized in six major categories: biotransformation, bioaccumulation/bisorption, biodegradation of chelators, volatilization, treatment trains, and natural attenuation. For all field applications there are ...

  18. Self-similar aftershock rates

    CERN Document Server

    Davidsen, Jörn

    2016-01-01

    In many important systems exhibiting crackling noise --- intermittent avalanche-like relaxation response with power-law and, thus, self-similar distributed event sizes --- the "laws" for the rate of activity after large events are not consistent with the overall self-similar behavior expected on theoretical grounds. This is in particular true for the case of seismicity and a satisfying solution to this paradox has remained outstanding. Here, we propose a generalized description of the aftershock rates which is both self-similar and consistent with all other known self-similar features. Comparing our theoretical predictions with high resolution earthquake data from Southern California we find excellent agreement, providing in particular clear evidence for a unified description of aftershocks and foreshocks. This may offer an improved way of time-dependent seismic hazard assessment and earthquake forecasting.

  19. Self-similar aftershock rates

    Science.gov (United States)

    Davidsen, Jörn; Baiesi, Marco

    2016-08-01

    In many important systems exhibiting crackling noise—an intermittent avalanchelike relaxation response with power-law and, thus, self-similar distributed event sizes—the "laws" for the rate of activity after large events are not consistent with the overall self-similar behavior expected on theoretical grounds. This is particularly true for the case of seismicity, and a satisfying solution to this paradox has remained outstanding. Here, we propose a generalized description of the aftershock rates which is both self-similar and consistent with all other known self-similar features. Comparing our theoretical predictions with high-resolution earthquake data from Southern California we find excellent agreement, providing particularly clear evidence for a unified description of aftershocks and foreshocks. This may offer an improved framework for time-dependent seismic hazard assessment and earthquake forecasting.

  20. Contextual Bandits with Similarity Information

    CERN Document Server

    Slivkins, Aleksandrs

    2009-01-01

    In a multi-armed bandit (MAB) problem, an online algorithm makes a sequence of choices. In each round it chooses from a time-invariant set of alternatives and receives the payoff associated with this alternative. While the case of small strategy sets is by now well-understood, a lot of recent work has focused on MAB problems with exponentially or infinitely large strategy sets, where one needs to assume extra structure in order to make the problem tractable. In particular, recent literature considered information on similarity between arms. We consider similarity information in the setting of "contextual bandits", a natural extension of the basic MAB problem where before each round an algorithm is given the "context" -- a hint about the payoffs in this round. Contextual bandits are directly motivated by placing advertisements on webpages, one of the crucial problems in sponsored search. A particularly simple way to represent similarity information in the contextual bandit setting is via a "similarity distance...

  1. Similarity measures for protein ensembles

    DEFF Research Database (Denmark)

    Lindorff-Larsen, Kresten; Ferkinghoff-Borg, Jesper

    2009-01-01

    Analyses of similarities and changes in protein conformation can provide important information regarding protein function and evolution. Many scores, including the commonly used root mean square deviation, have therefore been developed to quantify the similarities of different protein conformations...... a synthetic example from molecular dynamics simulations. We then apply the algorithms to revisit the problem of ensemble averaging during structure determination of proteins, and find that an ensemble refinement method is able to recover the correct distribution of conformations better than standard single...

  2. Community Detection by Neighborhood Similarity

    Institute of Scientific and Technical Information of China (English)

    LIU Xu; XIE Zheng; YI Dong-Yun

    2012-01-01

    Detection of the community structure in a network is important for understanding the structure and dynamics of the network.By exploring the neighborhood of vertices,a local similarity metric is proposed,which can be quickly computed.The resulting similarity matrix retains the same support as the adjacency matrix.Based on local similarity,an agglomerative hierarchical clustering algorithm is proposed for community detection.The algorithm is implemented by an efficient max-heap data structure and runs in nearly linear time,thus is capable of dealing with large sparse networks with tens of thousands of nodes.Experiments on synthesized and real-world networks demonstrate that our method is efficient to detect community structures,and the proposed metric is the most suitable one among all the tested similarity indices.%Detection of the community structure in a network is important for understanding the structure and dynamics of the network. By exploring the neighborhood of vertices, a local similarity metric is proposed, which can be quickly computed. The resulting similarity matrix retains the same support as the adjacency matrix. Based on local similarity, an agglomerative hierarchical clustering algorithm is proposed for community detection. The algorithm is implemented by an efficient max-heap data structure and runs in nearly linear time, thus is capable of dealing with large sparse networks with tens of thousands of nodes. Experiments on synthesized and real-world networks demonstrate that our method is efficient to detect community structures, and the proposed metric is the most suitable one among all the tested similarity indices.

  3. Multiscale Modeling for Biomass Growth Associated with Bioremediation and Its Impact on Permeability Change and Distribution of Contaminants

    Science.gov (United States)

    Oka, G. K.; Pinder, G.

    2009-12-01

    Bioremediation involves using bacteria present in the soil or injected into the soil to degrade contaminants dissolved in groundwater. The degrading bacteria grow attached to the soil particles using the contaminants as substrate for growth. In the process, the pore spaces between soil particles get partially or totally blocked. This blocking, called bioclogging, affects an important parameter, the permeability of soil, which governs the distribution of contaminants in groundwater. The distribution of contaminants in turn affects the growth of bacteria through its changed availability pattern. We attempt to model the complex relationship between the growth of bacteria and biodegradation of the contaminants by coupling a 'Cellular Automata' (CA) model for biomass growth with a multiphase transport model for contaminants in groundwater. The growth in biomass of bacteria at the microscopic spatial scale is translated into a change in permeability at the macroscopic scale by using averaging techniques on CA grids regarding them as 'Representative Elementary Volume' (REV) elements. The results of simulation are presented and compared with a laboratory column experiment.

  4. Natural and Accelerated Bioremediation Research (NABIR) Field Research Center (FRC) Management Plan

    Energy Technology Data Exchange (ETDEWEB)

    Watson, D.B.

    2002-02-28

    The Environmental Sciences Division at Oak Ridge National Laboratory has established a Field Research Center (FRC) to support the Natural and Accelerated Bioremediation Research (NABIR) Program on the U.S. Department of Energy (DOE) Oak Ridge Reservation in Oak Ridge, Tennessee for the DOE Headquarters Office of Biological and Environmental Research within the Office of Science.

  5. MICROBIAL ANALYSIS OF MTBE, BTEX BIOREMEDIATION: BIONETS CONTAINING PM1, SOS, ISOLITE.

    Science.gov (United States)

    MTBE and BTEX (benzene, toluene, ethylbenzene, and xylene) are major problems of many sites in the United States. The objective of this study was to determine if biologically active in-situ BioNets could bioremediation MTBE and BTEX contaminated groundwater. Seven BioNets were ...

  6. MICROBIAL ANALYSIS OF MTBE, BTEX BIOREMEDIATION: BIONETS(TM) CONTAINING PM1, SOS, ISOLITE (R)

    Science.gov (United States)

    MTBE and BTEX (benzene, toluene, ethylbenzene, and xylene) are major problems of many sites in the United States. The objective of this study was to determine if biologically active in-situ BioNets could bioremediation MTBE and BTEX contaminated groundwater. Seven BioNets were ...

  7. BTEX AND MTBE BIOREMEDIATION: BIONETS™ CONTAINING SOS, PM1 AND ISOLITE®

    Science.gov (United States)

    MTBE and BTEX (benzene, toluene, ethylbenzene, and xylenes) are major problems of many sites in the United States. The objective of this study was to determine if biologically active in situ BioNets could bioremediate MTBE and BTEX contaminated groundwater. Seven BioNets w...

  8. MICROBIAL ANALYSIS OF MTBE, BTEX BIOREMEDIATION: BIONETS CONTAINING PM1, SOS, ISOLITE�

    Science.gov (United States)

    MTBE and BTEX (benzene, toluene, ethylbenzene, and xylene) are major problems of many sites in the United States. The objective of this study was to determine if biologically active in-situ BioNets could bioremediate MTBE and BTEX contaminated groundwater. Seven BioNets were plac...

  9. The Environmental Issues of DDT Pollution and Bioremediation: a Multidisciplinary Review.

    Science.gov (United States)

    Mansouri, Ahlem; Cregut, Mickael; Abbes, Chiraz; Durand, Marie-Jose; Landoulsi, Ahmed; Thouand, Gerald

    2017-01-01

    DDT (1,1,1-trichloro-2,2-bis(4-chlorophenyl) ethane) is probably the best known and most useful organochlorine insecticide in the world which was used since 1945 for agricultural purposes and also for vector-borne disease control such as malaria since 1955, until its banishment in most countries by the Stockholm convention for ecologic considerations. However, the World Health Organization allowed its reintroduction only for control of vector-borne diseases in some tropical countries in 2006. Due to its physicochemical properties and specially its persistence related with a half-life up to 30 years, DDT linked to several health and social problems which are due to its accumulation in the environment and its biomagnification properties in living organisms. This manuscript compiles a multidisciplinary review to evaluate primarily (i) the worldwide contamination of DDT and (ii) its (eco) toxicological impact onto living organisms. Secondly, several ways for DDT bioremediation from contaminated environment are discussed. For this, reports on DDT biodegradation capabilities by microorganisms and ways to enhance bioremediation strategies to remove DDT are presented. The different existing strategies for DDT bioremediation are evaluated with their efficiencies and limitations to struggle efficiently this contaminant. Finally, rising new approaches and technological bottlenecks to promote DDT bioremediation are discussed.

  10. Bioremediation efficiency of the largest scale artificial Porphyra yezoensis cultivation in the open sea in China.

    Science.gov (United States)

    Wu, Hailong; Huo, Yuanzi; Zhang, Jianheng; Liu, Yuanyuan; Zhao, Yating; He, Peimin

    2015-06-15

    The bioremediation efficiency of China's largest scale Porphyra yezoensis cultivation for removing dissolved nutrients and controlling harmful algae was studied in the radial sandbanks waters of Jiangsu Province in the year 2012-2013. Mean nutrient concentration values in the P. yezoensis cultivation area were significantly lower than those in the non-cultivation area, especially during the cultivation season (popen sea.

  11. Bioremediation of refinery wastewater using immobilised Burkholderia cepacia and Corynebacterium sp and their transconjugants

    Directory of Open Access Journals (Sweden)

    Abdullahi T. Ajao

    2013-07-01

    Full Text Available When oil spill occurs, it poses serious toxic hazards to all forms of life. Mixed culture of Burkholderia cepacia and Corynebacterium sp isolated from refinery sludge using selective enrichment technique was used for bioremediation of refinery wastewater in a laboratoryscale bioreactor. Physicochemical parameters of both raw and treated water were as determined and compared with Federal Environ - mental Protection Agency (FEPA-limit, Abuja, Nigeria to asses the efficiency of the bioremediation process. Each of the bacterium was screened for the presence of plasmid DNA and for the involvement or otherwise of plasmid in the bioremediation of wastewater. The immobilised cells showed percentage decrease in chemical oxygen demand (97%, biochemical oxygen demand (94%, phenol (98%, total petroleum hydrocarbon (79%, oil and grease (90% of the refinery waste water after 20 days of treatment while their transconjugants showed the multiplicative effect by achieving the same percentage after 10 days of treatment. Therefore, the findings revealed that bioaugmentation of wastewater using transmissible catabolic plasmid will enhance efficiency of the bioremediation by spreading the plasmid among indigenous microbial community either through horizontal gene transfer or transformation.

  12. Recovery of microbial diversity and activity during bioremediation following chemical oxidation of diesel contaminated soils

    NARCIS (Netherlands)

    Sutton, N.B.; Langenhoff, A.A.M.; Hidalgo Lasso, D.; Zaan, van der B.M.; Gaans, van P.; Maphosa, F.; Smidt, H.; Grotenhuis, J.T.C.; Rijnaarts, H.H.M.

    2014-01-01

    To improve the coupling of in situ chemical oxidation and in situ bioremediation, a systematic analysis was performed of the effect of chemical oxidation with Fenton's reagent, modified Fenton's reagent, permanganate, or persulfate, on microbial diversity and activity during 8 weeks of incubation in

  13. Bioremediation of heavy metal contaminated aqueous solution by using red algae Porphyra leucosticta.

    Science.gov (United States)

    Ye, Jianjun; Xiao, Henglin; Xiao, Benlin; Xu, Weisheng; Gao, Linxia; Lin, Gan

    2015-01-01

    Bioremediation is an effective process for the removal and recovery of heavy metal ions from aqueous solutions. In this study, red algae Porphyra leucosticta was examined to remove Cd(II) and Pb(II) ions from wastewater through biological enrichment and biological precipitation. The experimental parameters that affect the bioremediation process such as pH, contact time and biomass dosage were studied. The maximum bioremediation capacity of metal ions was 31.45 mg/g for Cd(II) and 36.63 mg/g for Pb(II) at biomass dosage 15 g/L, pH 8.0 and contact time 120 minutes containing initial 10.0 mg/L of Cd(II) and 10.0 mg/L of Pb(II) solution. Red algae Porphyra leucosticta biomass was efficient at removing metal ions of 10.0 mg/L of Cd(II) and 10.0 mg/L of Pb(II) solution with bioremediation efficiency of 70% for Cd(II) and 90% for Pb(II) in optimal conditions. At the same time, the removal capacity for real industrial effluent was gained at 75% for 7.6 mg/L Cd(II) and 95% for 8.9 mg/L Pb(II). In conclusion, it is demonstrated that red algae Porphyra leucosticta is a promising, efficient, cheap and biodegradable sorbent biomaterial for reducing heavy metal pollution in the environment and wastewater.

  14. NUTRIENT TRANSPORT DURING BIOREMEDIATION OF CONTAMINATED BEACHES: EVALUATION WITH LITHIUM AS A CONSERVATIVE TRACER

    Science.gov (United States)

    Bioremediation of oil-contaminated beaches typically involves fertilization with nutrients that are thought to limit the growth rate of hydrocarbon-degrading bacteria. Much of the available technology involves application of fertilizers that release nutrients in a water-soluble ...

  15. Commercial cultivation and bioremediation potential of sugar kelp, Saccharina latissima, in Danish waters

    DEFF Research Database (Denmark)

    Silva Marinho, Goncalo; Holdt, Susan Løvstad; Birkeland, Mads J.;

    2015-01-01

    Several seaweed species have been successfully tested for their biofilter potential for integrated multi-trophic aquaculture (IMTA). In this study, Saccharina latissima bioremediation potential was assessed over 12 months with respect to the yield, phosphorous (P), nitrogen (N) content and N...... consumption, it is better to harvest in May where the seaweed is free of epiphytes....

  16. Profiling bacterial communities associated with sediment-based aquaculture bioremediation systems under contrasting redox regimes

    Science.gov (United States)

    Robinson, Georgina; Caldwell, Gary S.; Wade, Matthew J.; Free, Andrew; Jones, Clifford L. W.; Stead, Selina M.

    2016-12-01

    Deposit-feeding invertebrates are proposed bioremediators in microbial-driven sediment-based aquaculture effluent treatment systems. We elucidate the role of the sediment reduction-oxidation (redox) regime in structuring benthic bacterial communities, having direct implications for bioremediation potential and deposit-feeder nutrition. The sea cucumber Holothuria scabra was cultured on sediments under contrasting redox regimes; fully oxygenated (oxic) and redox stratified (oxic-anoxic). Taxonomically, metabolically and functionally distinct bacterial communities developed between the redox treatments with the oxic treatment supporting the greater diversity; redox regime and dissolved oxygen levels were the main environmental drivers. Oxic sediments were colonised by nitrifying bacteria with the potential to remediate nitrogenous wastes. Percolation of oxygenated water prevented the proliferation of anaerobic sulphate-reducing bacteria, which were prevalent in the oxic-anoxic sediments. At the predictive functional level, bacteria within the oxic treatment were enriched with genes associated with xenobiotics metabolism. Oxic sediments showed the greater bioremediation potential; however, the oxic-anoxic sediments supported a greater sea cucumber biomass. Overall, the results indicate that bacterial communities present in fully oxic sediments may enhance the metabolic capacity and bioremediation potential of deposit-feeder microbial systems. This study highlights the benefits of incorporating deposit-feeding invertebrates into effluent treatment systems, particularly when the sediment is oxygenated.

  17. Characterization of bacterial consortia for its use in bioremediation of gas-oil contaminated antarctic soils

    Energy Technology Data Exchange (ETDEWEB)

    Ruberto, L.; Vazquez, S.; Mestre, C.; Nogales, B.; Christie-Oleza, J.; Bosch, R.; Mac Cormack, W. P.

    2009-07-01

    Success of bio augmentation of chronically-contaminated soils is controversial, mainly because the inocula are frequently unable to establish in the matrix under bioremediation. In Antarctica, the environmental conditions and the restriction for the introduction of non-autochthonous organisms (imposed by the Antarctic Treaty) prevent inoculation with foreign bacteria. (Author)

  18. Changes in toxicity during in situ bioremediation of weathered drill wastes contaminated with petroleum hydrocarbons.

    Science.gov (United States)

    Steliga, Teresa; Jakubowicz, Piotr; Kapusta, Piotr

    2012-12-01

    Bioremediation of weathered drill wastes severely contaminated with total petroleum hydrocarbons (TPH) (90,000-170,000 mg kg(-1)) and BTEX (51.2-95.5 mg kg(-1)) to soil standards was achieved over a 3-year period in three phases: initial remediation, basic bioremediation and inoculation with a biopreparation. Fourteen non-pathogenic indigenous bacteria species belonging mainly to the Actinomycetales were identified and shown to be able to degrade 63-75% of nC(9)-nC(20), 36-51% of nC(21)-nC(36), 36% of BTEX and 20% of PAHs (polycyclic aromatic hydrocarbons). Addition of five non-pathogenic fungi species to the bacterial consortium allowed degradation of 69-89% of nC(9)-nC(20), 47-80% of nC(21)-nC(36), 76% of BTEX, and 68% of PAHs. Microtox, Ostacodtoxkit, Phytotoxkit and Ames tests indicated that changes in toxicity were not connected with the decrease in TPH contents, possibly due to the formation of toxic indirect metabolites during bioremediation. No toxicity was found in the soil after bioremediation.

  19. APPLIED GEOLOGIC, MICROBIOLOGICAL, AND ENGINEERING CONSTRAINTS OF IN-SITU BTEX BIOREMEDIATION

    Science.gov (United States)

    An in-situ bioremediation project has been designed and constructed for a site in south-central Kansas just north of Wichita. A pipeline leaked an unknown quantity of refinedfuels in the 1970s. The spill was undetected until hydrocarbons were found in a nearby municipal water sup...

  20. Ecotoxicity monitoring of hydrocarbon-contaminated soil during bioremediation: a case study.

    Science.gov (United States)

    Hubálek, Tomás; Vosáhlová, Simona; Matejů, Vít; Kovácová, Nora; Novotný, Cenek

    2007-01-01

    The ecotoxicity of hydrocarbon-contaminated soil originating from a brownfield site was evaluated during a 17-month biodegradation pilot test. The initial concentration of total petroleum hydrocarbons (TPHs) in the soil was 6380 microg/g dry weight. An amount of 200 kg soil was inoculated with 1.5 L of the bacterial preparation GEM-100 containing Pseudomonas sp. and Acinetobacter sp. strains (5.3 x 10(10) CFU.mL(-1)) adapted to diesel fuel. The concentration of TPHs in the soil decreased by 65.5% after bioremediation. Different organisms such as the bacterium Vibrio fischeri, terrestrial plants Sinapis alba, Lactuca sativa, and Hordeum vulgare, the water plant Lemna minor, the earthworm Eisenia fetida, and the crustacean Heterocypris incongruens were used for ecotoxicity evaluation. The highest toxicity was detected in the first period of bioremediation. However, certain toxic effects were detectable during the whole bioremediation process. The contact tests with plants, earthworms, and crustaceans were the most sensitive of all of the bioassays. Therefore, the contact tests performed directly on soil samples were shown to be a better tool for ecotoxicity evaluation of hydrocarbon-contaminated soil than the tests performed on soil elutriates. The ecotoxicity measured by the responses of the tests did not always correlate with the decrease in TPH concentrations in the soil during bioremediation.

  1. Feasibility of on-site bioremediation of loam soil contaminated by diesel oil.

    Science.gov (United States)

    Rubin, H; Narkis, N

    2001-09-01

    This study originated from an accidental event of diesel oil contamination in a loam soil area of 7,000 m2. Approximately a volume of 1,300 m3 of diesel oil was released into the environment. Reclamation of the contaminated soil by on-site bioremediation was selected as the most appropriate treatment method. A major concern was associated with the nature of the local loam soil. Loam has a very low hydraulic conductivity and very quickly becomes impermeable after its contact with water. The bioremediation approach incorporated excavation of the contaminated soil, mixing it with an agent, which increased its permeability. Following this preliminary treatment came the construction of bioreactors as a suitable environment of nutrients, moisture, dissolved oxygen, and enriched culture of microorganisms, which enabled breakdown of the diesel oil. This case study indicated that the target of 99% of diesel oil clean up could be achieved by using the technology of on-site bioremediation. The selected treatment method was found to be technologically and economically feasible. However, some improvement in the application of the basic treatment approach might increase the bioremediation efficiency.

  2. Bioremediation in marine ecosystems: a computational study combining ecological modelling and flux balance analysis

    Directory of Open Access Journals (Sweden)

    Marianna eTaffi

    2014-09-01

    Full Text Available The pressure to search effective bioremediation methodologies for contaminated ecosystems has led to the large-scale identification of microbial species and metabolic degradation pathways. However, minor attention has been paid to the study of bioremediation in marine food webs and to the definition of integrated strategies for reducing bioaccumulation in species. We propose a novel computational framework for analysing the multiscale effects of bioremediation at the ecosystem level, based on coupling food web bioaccumulation models and metabolic models of degrading bacteria. The combination of techniques from synthetic biology and ecological network analysis allows the specification of arbitrary scenarios of contaminant removal and the evaluation of strategies based on natural or synthetic microbial strains.In this study, we derive a bioaccumulation model of polychlorinated biphenyls (PCBs in the Adriatic food web, and we extend a metabolic reconstruction of Pseudomonas putida KT2440 (iJN746 with the aerobic pathway of PCBs degradation. We assess the effectiveness of different bioremediation scenarios in reducing PCBs concentration in species and we study indices of species centrality to measure their importance in the contaminant diffusion via feeding links.The analysis of the Adriatic sea case study suggests that our framework could represent a practical tool in the design of effective remediation strategies, providing at the same time insights into the ecological role of microbial communities within food webs.

  3. Bioremediation in marine ecosystems: a computational study combining ecological modeling and flux balance analysis.

    Science.gov (United States)

    Taffi, Marianna; Paoletti, Nicola; Angione, Claudio; Pucciarelli, Sandra; Marini, Mauro; Liò, Pietro

    2014-01-01

    The pressure to search effective bioremediation methodologies for contaminated ecosystems has led to the large-scale identification of microbial species and metabolic degradation pathways. However, minor attention has been paid to the study of bioremediation in marine food webs and to the definition of integrated strategies for reducing bioaccumulation in species. We propose a novel computational framework for analysing the multiscale effects of bioremediation at the ecosystem level, based on coupling food web bioaccumulation models and metabolic models of degrading bacteria. The combination of techniques from synthetic biology and ecological network analysis allows the specification of arbitrary scenarios of contaminant removal and the evaluation of strategies based on natural or synthetic microbial strains. In this study, we derive a bioaccumulation model of polychlorinated biphenyls (PCBs) in the Adriatic food web, and we extend a metabolic reconstruction of Pseudomonas putida KT2440 (iJN746) with the aerobic pathway of PCBs degradation. We assess the effectiveness of different bioremediation scenarios in reducing PCBs concentration in species and we study indices of species centrality to measure their importance in the contaminant diffusion via feeding links. The analysis of the Adriatic sea case study suggests that our framework could represent a practical tool in the design of effective remediation strategies, providing at the same time insights into the ecological role of microbial communities within food webs.

  4. Bioremediation of endosulfan in laboratory-scale constructed wetlands: effect of bioaugmentation and biostimulation.

    Science.gov (United States)

    Zhao, Congcong; Xie, HuiJun; Mu, Yang; Xu, Xiaoli; Zhang, Jian; Liu, Cui; Liang, Shuang; Ngo, Huu Hao; Guo, Wenshan; Xu, Jingtao; Wang, Qian

    2014-11-01

    Bioremediation is widely used in organic pollutants disposal. However, very little has been known on its application in constructed wetlands contaminated with organochlorine pesticide, endosulfan in particular. To evaluate the effect of bioremediation on endosulfan removal and clarify the fate, bioaugmentation and biostimulation were studied in laboratory-scale vertical-flow constructed wetlands. After 20 days' experiment, endosulfan isomers removal efficiencies were increased to 89.24-97.62 % through bioremediation. In bacteria bioaugmentation (E-in) and sucrose biostimulation (E-C), peak concentrations of endosulfan in sediment were reduced by 31.02-76.77 %, and plant absorption were 347.45-576.65 μg kg(-1). By contrast, plant absorption in KH2PO4 biostimulation (E-P) was increased to 811.64 and 1,067.68 μg kg(-1). Degradation process was probably promoted in E-in and E-C, while plant absorption was enhanced in E-P. Consequently, E-in and E-C were effective for endosulfan removal in constructed wetlands, while adding KH2PO4 had potential to cause air pollution. Additionally, combined bioremediation was not recommended.

  5. Bioremediation strategies for removal of residual atrazine in the boreal groundwater zone.

    Science.gov (United States)

    Nousiainen, Aura O; Björklöf, Katarina; Sagarkar, Sneha; Nielsen, Jeppe Lund; Kapley, Atya; Jørgensen, Kirsten S

    2015-12-01

    Strategies for bioremediation of atrazine, a pesticide commonly polluting groundwater in low concentrations, were studied in two boreal nonagricultural soils. Atrazine was not mineralized in soil without bioremediation treatments. In biostimulation treatment with molasses, up to 52% of atrazine was mineralized at 10 °C, even though the degradation gene copy numbers did not increase. Incubations with radioactively labeled atrazine followed by microautoradiographic analysis revealed that bioremediation strategies increased the relative proportion of active degraders from 0.3 up to 1.9% of the total bacterial count. These results indicate that atrazine degradation might not solely be facilitated by atzA/trzN-atzB genes. In combined biostimulation treatment using citrate or molasses and augmentation with Pseudomonas citronellolis ADP or Arthrobacter aurescens strain TC1, up to 76% of atrazine was mineralized at 30 °C, and the atrazine degradation gene numbers increased up to 10(7) copies g(-1) soil. Clone libraries from passive samplers in groundwater monitoring wells revealed the presence of phylogenetic groups formerly shown to include atrazine degraders, and the presence of atrazine degradation genes atzA and atzB. These results show that the mineralization of low concentrations of atrazine in the groundwater zone at low temperatures is possible by bioremediation treatments.

  6. Intrinsic and enhanced bioremediation in aquifers contaminated with chlorinated and aromatic hydrocarbons in The Netherlands

    NARCIS (Netherlands)

    Rijnaarts, H.H.M.; Aalst-van Leeuwen, M.A. van; Heiningen, E. van; Buyzen, H. van; Sinke, A.; Liere, H.C. van; Harkes, M.; Baartmans, R.; Bosma, T.N.P.; Doddema, H.J.

    1998-01-01

    The feasibility of intrinsic and enhanced bioremediation approaches for 16 contaminated sites in the Netherlands are discussed. At at least five out of 10 chlorinated solvent sites, natural attenuation can be used as one of the tools to prevent further dispersion of the plume. At two sites stimulati

  7. TOXICITY TRENDS DURING AN OIL SPILL BIOREMEDIATION EXPERIMENT ON A SANDY SHORELINE IN DELAWARE, USA

    Science.gov (United States)

    A 13-week, refereed, inter-agency toxicity testing program involving five bioassay methods was used to document the effectiveness of shoreline bioremediation to accelerate toxicity reduction of an oiled sandy shoreline at Fowler Beach, Delaware, USA. The study was part of an inte...

  8. Effect of alternating bioremediation and electrokinetics on the remediation of n-hexadecane-contaminated soil

    Science.gov (United States)

    Wang, Sa; Guo, Shuhai; Li, Fengmei; Yang, Xuelian; Teng, Fei; Wang, Jianing

    2016-04-01

    This study demonstrated the highly efficient degradation of n-hexadecane in soil, realized by alternating bioremediation and electrokinetic technologies. Using an alternating technology instead of simultaneous application prevented competition between the processes that would lower their efficiency. For the consumption of the soil dissolved organic matter (DOM) necessary for bioremediation by electrokinetics, bioremediation was performed first. Because of the utilization and loss of the DOM and water-soluble ions by the microbial and electrokinetic processes, respectively, both of them were supplemented to provide a basic carbon resource, maintain a high electrical conductivity and produce a uniform distribution of ions. The moisture and bacteria were also supplemented. The optimal DOM supplement (20.5 mg·kg-1 glucose; 80-90% of the total natural DOM content in the soil) was calculated to avoid competitive effects (between the DOM and n-hexadecane) and to prevent nutritional deficiency. The replenishment of the water-soluble ions maintained their content equal to their initial concentrations. The degradation rate of n-hexadecane was only 167.0 mg·kg-1·d-1 (1.9%, w/w) for the first 9 days in the treatments with bioremediation or electrokinetics alone, but this rate was realized throughout the whole process when the two technologies were alternated, with a degradation of 78.5% ± 2.0% for the n-hexadecane after 45 days of treatment.

  9. Ripening of PAH and TPH polluted sediments : determination and quantification of bioremediation parameters

    NARCIS (Netherlands)

    Vermeulen, J.

    2007-01-01

    In this study, bioremediation parameters were determined and quantified for different clayey dredged sediments. The research described in this thesis increased the insight into the individual processes of physical ripening, biochemical ripening – including PAH and TPH degradation – that result from

  10. DEVELOPMENT AND APPLICATION OF PROTOCOLS FOR EVALUATION OF OIL SPILL BIOREMEDIATION (RESEARCH BRIEF)

    Science.gov (United States)

    Protocols were developed and evaluated to assess the efficacy and environmental safety of commercial oil spill bioremediation agents (CBAs). Test systems that simulate oil slicks on open water or oiled sandy beaches were used to test the effectiveness of CBAs. Gravimetric and gas...

  11. Mineral transformation and biomass accumulation associated with uranium bioremediation at Rifle, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Li, L.; Steefel, C.I.; Williams, K.H.; Wilkins, M.J.; Hubbard, S.S.

    2009-04-20

    Injection of organic carbon into the subsurface as an electron donor for bioremediation of redox-sensitive contaminants like uranium often leads to mineral transformation and biomass accumulation, both of which can alter the flow field and potentially bioremediation efficacy. This work combines reactive transport modeling with a column experiment and field measurements to understand the biogeochemical processes and to quantify the biomass and mineral transformation/accumulation during a bioremediation experiment at a uranium contaminated site near Rifle, Colorado. We use the reactive transport model CrunchFlow to explicitly simulate microbial community dynamics of iron and sulfate reducers, and their impacts on reaction rates. The column experiment shows clear evidence of mineral precipitation, primarily in the form of calcite and iron monosulfide. At the field scale, reactive transport simulations suggest that the biogeochemical reactions occur mostly close to the injection wells where acetate concentrations are highest, with mineral precipitate and biomass accumulation reaching as high as 1.5% of the pore space. This work shows that reactive transport modeling coupled with field data can be an effective tool for quantitative estimation of mineral transformation and biomass accumulation, thus improving the design of bioremediation strategies.

  12. BIOSTIMULATION CAN SOMETIMES ENHANCE ENVIRONMENTAL CLEANUP - An Editorial Viewpoint on Bioremediation

    Science.gov (United States)

    The Exxon Valdex oil spill, which led to the enactment of the Oil Pollution Act of 1990, gave rise to the largest bioremediation field trial ever attempted. A research sutdy was conducted by EPA in 1989 and 1990 to develop data to support the recommendation to go forward w...

  13. CONTAMINANT REDISTRIBUTION CAN CONFOUND INTERPRETATION OF OIL-SPILL BIOREMEDIATION STUDIES

    Science.gov (United States)

    The physical redistribution of oil between the inside and outside of experimental plots can affect the results of bioremediation field studies that are conducted on shorelines contaminated by real oil spills. Because untreated oil from the surrounding beach will enter the plot, ...

  14. LABORATORY EVALUATION OF OIL SPILL BIOREMEDIATION PRODUCTS IN SALT AND FRESHWATER SYSTEMS

    Science.gov (United States)

    Ten oil spill bioremediation products were tested in the laboratory for their ability to enhance biodegradation of weathered Alaskan North Slope crude oil in both fresh and salt-water media. The products included: nutrients to stimulate inoculated microorganisms, nutrients plus a...

  15. Modelling and monitoring of Aquifer Thermal Energy Storage : impacts of soil heterogeneity, thermal interference and bioremediation

    NARCIS (Netherlands)

    Sommer, W.T.

    2015-01-01

    Modelling and monitoring of Aquifer Thermal Energy Storage Impacts of heterogeneity, thermal interference and bioremediation Wijbrand Sommer
    PhD thesis, Wageningen University, Wageningen, NL (2015)
    ISBN 978-94-6257-294-2 Abstract Aquifer thermal energy storage (ATES) is

  16. Genome Sequence of Klebsiella quasipneumoniae subsp. similipneumoniae MB373, an Effective Bioremediator

    Science.gov (United States)

    Aslam, Fozia; Thomas, Torsten

    2016-01-01

    Klebsiella quasipneumoniae subsp. similipneumoniae MB373 was isolated from effluent of the Hattar Industrial Estate, Haripur, Pakistan. K. quasipneumoniae subsp. similipneumoniae has few cultivated/characterized members so far. Whole-genome sequencing revealed its potential for metal and toxin resistance, which further elucidated various enzymatic processes for the degradation of xenobiotics, illuminating its bioremediation applications. PMID:27688323

  17. Bioremediation of weathered petroleum hydrocarbon soil contamination in the Canadian High Arctic: laboratory and field studies.

    Science.gov (United States)

    Sanscartier, David; Laing, Tamsin; Reimer, Ken; Zeeb, Barbara

    2009-11-01

    The bioremediation of weathered medium- to high-molecular weight petroleum hydrocarbons (HCs) in the High Arctic was investigated. The polar desert climate, contaminant characteristics, and logistical constraints can make bioremediation of persistent HCs in the High Arctic challenging. Landfarming (0.3 m(3) plots) was tested in the field for three consecutive years with plots receiving very little maintenance. Application of surfactant and fertilizers, and passive warming using a greenhouse were investigated. The field study was complemented by a laboratory experiment to better understand HC removal mechanisms and limiting factors affecting bioremediation on site. Significant reduction of total petroleum HCs (TPH) was observed in both experiments. Preferential removal of compounds nC16 occurred, whereas in the field, TPH reduction was mainly limited to removal of compounds nC16 was observed in the fertilized field plots only. The greenhouse increased average soil temperatures and extended the treatment season but did not enhance bioremediation. Findings suggest that temperature and low moisture content affected biodegradation of HCs in the field. Little volatilization was measured in the laboratory, but this process may have been predominant in the field. Low-maintenance landfarming may be best suited for remediation of HCs compounds

  18. EVALUATION OF BIOREMEDIATION STRATEGIES OF A CONTROLLED OIL RELEASE IN A WETLAND

    Science.gov (United States)

    A controlled petroleum release was conducted to evaluate bioremediation in a wetland near Houston, Texas. The 140-day study was conducted using a randomized, complete block design to test three treatments with six replicates per treatment. The three treatment strategies were in...

  19. Microorganisms in heavy metal bioremediation: strategies for applying microbial-community engineering to remediate soils

    Directory of Open Access Journals (Sweden)

    Jennifer L. Wood

    2016-06-01

    Full Text Available The remediation of heavy-metal-contaminated soils is essential as heavy metals persist and do not degrade in the environment. Remediating heavy-metal-contaminated soils requires metals to be mobilized for extraction whilst, at the same time, employing strategies to avoid mobilized metals leaching into ground-water or aquatic systems. Phytoextraction is a bioremediation strategy that extracts heavy metals from soils by sequestration in plant tissues and is currently the predominant bioremediation strategy investigated for remediating heavy-metal-contaminated soils. Although the efficiency of phytoextraction remains a limiting feature of the technology, there are numerous reports that soil microorganisms can improve rates of heavy metal extraction.This review highlights the unique challenges faced when remediating heavy-metal-contaminated soils as compared to static aquatic systems and suggests new strategies for using microorganisms to improve phytoextraction. We compare how microorganisms are used in soil bioremediation (i.e. phytoextraction and water bioremediation processes, discussing how the engineering of microbial communities, used in water remediation, could be applied to phytoextraction. We briefly outline possible approaches for the engineering of soil communities to improve phytoextraction either by mobilizing metals in the rhizosphere of the plant or by promoting plant growth to increase the root-surface area available for uptake of heavy metals. We highlight the technological advances that make this research direction possible and how these technologies could be employed in future research.

  20. Profiling bacterial communities associated with sediment-based aquaculture bioremediation systems under contrasting redox regimes

    Science.gov (United States)

    Robinson, Georgina; Caldwell, Gary S.; Wade, Matthew J.; Free, Andrew; Jones, Clifford L. W.; Stead, Selina M.

    2016-01-01

    Deposit-feeding invertebrates are proposed bioremediators in microbial-driven sediment-based aquaculture effluent treatment systems. We elucidate the role of the sediment reduction-oxidation (redox) regime in structuring benthic bacterial communities, having direct implications for bioremediation potential and deposit-feeder nutrition. The sea cucumber Holothuria scabra was cultured on sediments under contrasting redox regimes; fully oxygenated (oxic) and redox stratified (oxic-anoxic). Taxonomically, metabolically and functionally distinct bacterial communities developed between the redox treatments with the oxic treatment supporting the greater diversity; redox regime and dissolved oxygen levels were the main environmental drivers. Oxic sediments were colonised by nitrifying bacteria with the potential to remediate nitrogenous wastes. Percolation of oxygenated water prevented the proliferation of anaerobic sulphate-reducing bacteria, which were prevalent in the oxic-anoxic sediments. At the predictive functional level, bacteria within the oxic treatment were enriched with genes associated with xenobiotics metabolism. Oxic sediments showed the greater bioremediation potential; however, the oxic-anoxic sediments supported a greater sea cucumber biomass. Overall, the results indicate that bacterial communities present in fully oxic sediments may enhance the metabolic capacity and bioremediation potential of deposit-feeder microbial systems. This study highlights the benefits of incorporating deposit-feeding invertebrates into effluent treatment systems, particularly when the sediment is oxygenated. PMID:27941918

  1. Colloidal properties of nanoparticular biogenic selenium govern environmental fate and bioremediation effectiveness

    NARCIS (Netherlands)

    Buchs, B.; Evangelou, M.H.W.; Winkel, L.; Lenz, M.

    2013-01-01

    Microbial selenium (Se) bioremediation is based on conversion of water soluble, toxic Se oxyanions to water insoluble, elemental Se. Formed biogenic elemental Se is of nanometer size, hampering straightforward separation from the aqueous phase. This study represents the first systematic investigatio

  2. Monitoring Genetic and Metabolic Potential for In-Situ Bioremediation: Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Buchanan, Michelle V.; Britt, Phillip F.; Doktycz, Mitchel J.; Hurst, Gregory B.; Lidstrom, Mary E.

    2000-06-01

    A number of DOE sites are contaminated with dense non-aqueous phase liquids (DNAPLs) such as carbon tetrachloride and trichloroethylene. At many of these sites, microbial bioremediation is an attractive strategy for cleanup, since it has the potential to degrade DNAPLs in situ. A rapid screening method to determine the broad range potential of a site's microbial population for contaminant degradation would greatly facilitate assessment for in situ bioremediation, as well as for monitoring ongoing bioremediation treatment. Current laboratory-based treatability methods are cumbersome and expensive. In this project, we are developing methods based on matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) for rapid and accurate detection of polymerase chain reaction (PCR) products from microbial genes involved in biodegradation of pollutants. PCR primers are being developed to amplify DNA sequences that are amenable to MALDI-MS detection. This work will lay the foundation for development of a field-portable MS-based technique for rapid on site assessment and monitoring of bioremediation processes.

  3. A review on slurry bioreactors for bioremediation of soils and sediments

    Directory of Open Access Journals (Sweden)

    Poggi-Varaldo Héctor M

    2008-02-01

    Full Text Available Abstract The aim of this work is to present a critical review on slurry bioreactors (SB and their application to bioremediation of soils and sediments polluted with recalcitrant and toxic compounds. The scope of the review encompasses the following subjects: (i process fundamentals of SB and analysis of advantages and disadvantages; (ii the most recent applications of SB to laboratory scale and commercial scale soil bioremediation, with a focus on pesticides, explosives, polynuclear aromatic hydrocarbons, and chlorinated organic pollutants; (iii trends on the use of surfactants to improve availability of contaminants and supplementation with degradable carbon sources to enhance cometabolism of pollutants; (iv recent findings on the utilization of electron acceptors other than oxygen; (v bioaugmentation and advances made on characterization of microbial communities of SB; (vi developments on ecotoxicity assays aimed at evaluating bioremediation efficiency of the process. From this review it can be concluded that SB is an effective ad situ and ex situ technology that can be used for bioremediation of problematic sites, such as those characterized by soils with high contents of clay and organic matter, by pollutants that are recalcitrant, toxic, and display hysteretic behavior, or when bioremediation should be accomplished in short times under the pressure and monitoring of environmental agencies and regulators. SB technology allows for the convenient manipulation and control of several environmental parameters that could lead to enhanced and faster treatment of polluted soils: nutrient N, P and organic carbon source (biostimulation, inocula (bioaugmentation, increased availability of pollutants by use of surfactants or inducing biosurfactant production inside the SB, etc. An interesting emerging area is the use of SB with simultaneous electron acceptors, which has demonstrated its usefulness for the bioremediation of soils polluted with

  4. Practical Bioremediation Course – Laboratory Exercises on Biodegradation of Cationic Surfactant

    Directory of Open Access Journals (Sweden)

    Tomislav Ivankovic

    2015-02-01

    Full Text Available 0 From the perspective of the lab exercises leader and teaching assistant for the Bioremediation course, it was very difficult to design and conduct a set of exercises that would fit the course curriculum and satisfactorily demonstrate bioremediation basics through practical laboratory work. Thus, Bioremediation course students designed the experiment with the help of the teaching assistant; a simulation of possible bioremediation of “Jarun” lake in Zagreb, Croatia, if contaminated with cationic surfactant. The experiment nicely showed how natural bioremediation differs from engineered bioremediation and the levels of success between different types of engineered bioremediation. The laboratory exercises were designed to be interesting and the results perceivable to the students.  Editor's Note:The ASM advocates that students must successfully demonstrate the ability to explain and practice safe laboratory techniques. For more information, read the laboratory safety section of the ASM Curriculum Recommendations: Introductory Course in Microbiology and the Guidelines for Biosafety in Teaching Laboratories, available at www.asm.org. The Editors of JMBE recommend that adopters of the protocols included in this article follow a minimum of Biosafety Level 2 practices. Normal 0 21 false false false HR X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Cambria","serif"; mso-ascii-font-family:Cambria; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Cambria; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}

  5. Similarity of atoms in molecules

    Energy Technology Data Exchange (ETDEWEB)

    Cioslowski, J.; Nanayakkara, A. (Florida State Univ., Tallahassee, FL (United States))

    1993-12-01

    Similarity of atoms in molecules is quantitatively assessed with a measure that employs electron densities within respective atomic basins. This atomic similarity measure does not rely on arbitrary assumptions concerning basis functions or 'atomic orbitals', is relatively inexpensive to compute, and has straightforward interpretation. Inspection of similarities between pairs of carbon, hydrogen, and fluorine atoms in the CH[sub 4], CH[sub 3]F, CH[sub 2]F[sub 2], CHF[sub 3], CF[sub 4], C[sub 2]H[sub 2], C[sub 2]H[sub 4], and C[sub 2]H[sub 6] molecules, calculated at the MP2/6-311G[sup **] level of theory, reveals that the atomic similarity is greatly reduced by a change in the number or the character of ligands (i.e. the atoms with nuclei linked through bond paths to the nucleus of the atom in question). On the other hand, atoms with formally identical (i.e. having the same nuclei and numbers of ligands) ligands resemble each other to a large degree, with the similarity indices greater than 0.95 for hydrogens and 0.99 for non-hydrogens. 19 refs., 6 tabs.

  6. Bioremediation of {sup 60}Co from simulated spent decontamination solutions

    Energy Technology Data Exchange (ETDEWEB)

    Rashmi, K.; Naga Sowjanya, T.; Maruthi Mohan, P.; Balaji, V.; Venkateswaran, G

    2004-07-26

    Bioremediation of {sup 60}Co from simulated spent decontamination solutions by utilizing different biomass of (Neurospora crassa, Trichoderma viridae, Mucor recemosus, Rhizopus chinensis, Penicillium citrinum, Aspergillus niger and, Aspergillus flavus) fungi is reported. Various fungal species were screened to evaluate their potential for removing cobalt from very low concentrations (0.03-0.16 {mu}M) in presence of a high background of iron (9.33 mM) and nickel (0.93 mM) complexed with EDTA (10.3 mM). The different fungal isolates employed in this study showed a pickup of cobalt in the range 8-500 ng/g of dry biomass. The [Fe]/[Co] and [Ni]/[Co] ratios in the solutions before and after exposure to the fungi were also determined. At micromolar level the cobalt pickup by many fungi especially the mutants of N. crassa is seen to be proportional to the initial cobalt concentration taken in the solution. However, R. chinensis exhibits a low but iron concentration dependent cobalt pickup. Prior saturating the fungi with excess of iron during their growth showed the presence of selective cobalt pickup sites. The existence of cobalt specific sorption sites is shown by a model experiment with R. chinensis wherein at a constant cobalt concentration (0.034 {mu}M) and varying iron concentrations so as to yield [Fe/Co]{sub initial} ratios in solution of 10, 100, 1000 and 287 000 have all yielded a definite Co pickup capacity in the range 8-47 ng/g. The presence of Cr(III)EDTA (3 mM) in solution along with complexed Fe and Ni has not influenced the cobalt removal. The significant feature of this study is that even when cobalt is present in trace level (sub-micromolar) in a matrix of high concentration (millimolar levels) of iron, nickel and chromium, a situation typically encountered in spent decontamination solutions arising from stainless steel based primary systems of nuclear reactors, a number of fungi studied in this work showed a good sensitivity for cobalt pickup.

  7. Diagnosis of In Situ Metabolic State and Rates of Microbial Metabolism During In Situ Uranium Bioremediation with Molecular Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Lovley, Derek R. [University of Massachusetts, Amherst

    2012-11-28

    The goal of these projects was to develop molecule tools to tract the metabolic activity and physiological status of microorganisms during in situ uranium bioremediation. Such information is important in able to design improved bioremediation strategies. As summarized below, the research was highly successful with new strategies developed for estimating in situ rates of metabolism and diagnosing the physiological status of the predominant subsurface microorganisms. This is a first not only for groundwater bioremediation studies, but also for subsurface microbiology in general. The tools and approaches developed in these studies should be applicable to the study of microbial communities in a diversity of soils and sediments.

  8. Similarity measures for face recognition

    CERN Document Server

    Vezzetti, Enrico

    2015-01-01

    Face recognition has several applications, including security, such as (authentication and identification of device users and criminal suspects), and in medicine (corrective surgery and diagnosis). Facial recognition programs rely on algorithms that can compare and compute the similarity between two sets of images. This eBook explains some of the similarity measures used in facial recognition systems in a single volume. Readers will learn about various measures including Minkowski distances, Mahalanobis distances, Hansdorff distances, cosine-based distances, among other methods. The book also summarizes errors that may occur in face recognition methods. Computer scientists "facing face" and looking to select and test different methods of computing similarities will benefit from this book. The book is also useful tool for students undertaking computer vision courses.

  9. Biosensing and bioremediation of Cr(VI) by cell free extract of Enterobacter aerogenes T2.

    Science.gov (United States)

    Panda, Jigisha; Sarkar, Priyabrata

    2014-01-01

    Hexavalent chromium or Cr(VI) enters the environment through several anthropogenic activities and it is highly toxic and carcinogenic. Hence it is required to be detected and remediated from the environment. In this study, low-cost and environment-friendly methods of biosensing and bioremediation of Cr(VI) have been proposed. Crude cell free extract (CFE) of previously isolated Enterobacter aerogenes T2 (GU265554; NII 1111) was prepared and exploited to develop a stable biosensor for direct estimation of Cr(VI) in waste water, by using three electrodes via cyclic voltammetry. For bioremediation studies, a homogeneous solution of commercially available sodium alginate and CFE was added dropwise in a continuously stirred calcium chloride solution. Biologically modified calcium alginate beads were produced and these were further utilized for bioremediation studies. The proposed sensor showed linear response in the range of 10-40 μg L(-1) Cr(VI) and the limit of detection was found to be 6.6 μg L(-1) Cr(VI). No interference was observed in presence of metal ions, e.g., lead, cadmium, arsenic, tin etc., except for insignificant interference with molybdenum and manganese. In bioremediation studies, modified calcium alginate beads showed encouraging removal rate 900 mg Cr(VI)/m(3) water per day with a removal efficiency of 90%, much above than reported in literature. The proposed sensing system could be a viable alternative to costly measurement procedures. Calcium alginate beads, modified with CFE of E. aerogenes, could be used in bioremediation of Cr(VI) since it could work in real conditions with extraordinarily high capacity.

  10. The design of long-term effective uranium bioremediation strategy using a community metabolic model.

    Science.gov (United States)

    Zhuang, K; Ma, E; Lovley, Derek R; Mahadevan, Radhakrishnan

    2012-10-01

    Acetate amendment at uranium contaminated sites in Rifle, CO. leads to an initial bloom of Geobacter accompanied by the removal of U(VI) from the groundwater, followed by an increase of sulfate-reducing bacteria (SRBs) which are poor reducers of U(VI). One of the challenges associated with bioremediation is the decay in Geobacter abundance, which has been attributed to the depletion of bio-accessible Fe(III), motivating the investigation of simultaneous amendments of acetate and Fe(III) as an alternative bioremediation strategy. In order to understand the community metabolism of Geobacter and SRBs during artificial substrate amendment, we have created a genome-scale dynamic community model of Geobacter and SRBs using the previously described Dynamic Multi-species Metabolic Modeling framework. Optimization techniques are used to determine the optimal acetate and Fe(III) addition profile. Field-scale simulation of acetate addition accurately predicted the in situ data. The simulations suggest that batch amendment of Fe(III) along with continuous acetate addition is insufficient to promote long-term bioremediation, while continuous amendment of Fe(III) along with continuous acetate addition is sufficient to promote long-term bioremediation. By computationally minimizing the acetate and Fe(III) addition rates as well as the difference between the predicted and target uranium concentration, we showed that it is possible to maintain the uranium concentration below the environmental safety standard while minimizing the cost of chemical additions. These simulations show that simultaneous addition of acetate and Fe(III) has the potential to be an effective uranium bioremediation strategy. They also show that computational modeling of microbial community is an important tool to design effective strategies for practical applications in environmental biotechnology.

  11. Distance learning for similarity estimation

    NARCIS (Netherlands)

    Yu, J.; Amores, J.; Sebe, N.; Radeva, P.; Tian, Q.

    2008-01-01

    In this paper, we present a general guideline to find a better distance measure for similarity estimation based on statistical analysis of distribution models and distance functions. A new set of distance measures are derived from the harmonic distance, the geometric distance, and their generalized

  12. Distance learning for similarity estimation.

    Science.gov (United States)

    Yu, Jie; Amores, Jaume; Sebe, Nicu; Radeva, Petia; Tian, Qi

    2008-03-01

    In this paper, we present a general guideline to find a better distance measure for similarity estimation based on statistical analysis of distribution models and distance functions. A new set of distance measures are derived from the harmonic distance, the geometric distance, and their generalized variants according to the Maximum Likelihood theory. These measures can provide a more accurate feature model than the classical Euclidean and Manhattan distances. We also find that the feature elements are often from heterogeneous sources that may have different influence on similarity estimation. Therefore, the assumption of single isotropic distribution model is often inappropriate. To alleviate this problem, we use a boosted distance measure framework that finds multiple distance measures which fit the distribution of selected feature elements best for accurate similarity estimation. The new distance measures for similarity estimation are tested on two applications: stereo matching and motion tracking in video sequences. The performance of boosted distance measure is further evaluated on several benchmark data sets from the UCI repository and two image retrieval applications. In all the experiments, robust results are obtained based on the proposed methods.

  13. Comparison of hydrological similarity measures

    Science.gov (United States)

    Rianna, Maura; Ridolfi, Elena; Manciola, Piergiorgio; Napolitano, Francesco; Russo, Fabio

    2016-04-01

    The use of a traditional at site approach for the statistical characterization and simulation of spatio-temporal precipitation fields has a major recognized drawback. Indeed, the weakness of the methodology is related to the estimation of rare events and it involves the uncertainty of the at-site sample statistical inference, because of the limited length of records. In order to overcome the lack of at-site observations, regional frequency approach uses the idea of substituting space for time to estimate design floods. The conventional regional frequency analysis estimates quantile values at a specific site from multi-site analysis. The main idea is that homogeneous sites, once pooled together, have similar probability distribution curves of extremes, except for a scaling factor. The method for pooling groups of sites can be based on geographical or climatological considerations. In this work the region of influence (ROI) pooling method is compared with an entropy-based one. The ROI is a flexible pooling group approach which defines for each site its own "region" formed by a unique set of similar stations. The similarity is found through the Euclidean distance metric in the attribute space. Here an alternative approach based on entropy is introduced to cluster homogeneous sites. The core idea is that homogeneous sites share a redundant (i.e. similar) amount of information. Homogeneous sites are pooled through a hierarchical selection based on the mutual information index (i.e. a measure of redundancy). The method is tested on precipitation data in Central Italy area.

  14. HOW DISSIMILARLY SIMILAR ARE BIOSIMILARS?

    Directory of Open Access Journals (Sweden)

    Ramshankar Vijayalakshmi

    2012-05-01

    Full Text Available Recently Biopharmaceuticals are the new chemotherapeutical agents that are called as “Biosimilars” or “follow on protein products” by the European Medicines Agency (EMA and the American regulatory agencies (Food and Drug Administration respectively. Biosimilars are extremely similar to the reference molecule but not identical, however close their similarities may be. A regulatory framework is therefore in place to assess the application for marketing authorisation of biosimilars. When a biosimilar is similar to the reference biopharmaceutical in terms of safety, quality, and efficacy, it can be registered. It is important to document data from clinical trials with a view of similar safety and efficacy. If the development time for a generic medicine is around 3 years, a biosimilar takes about 6-9 years. Generic medicines need to demonstrate bioequivalence only unlike biosimilars that need to conduct phase I and Phase III clinical trials. In this review, different biosimilars that are already being used successfully in the field on Oncology is discussed. Their similarity, differences and guidelines to be followed before a clinically informed decision to be taken, is discussed. More importantly the regulatory guidelines that are operational in India with a work flow of making a biosimilar with relevant dos and dont’s are discussed. For a large populous country like India, where with improved treatments in all sectors including oncology, our ageing population is increasing. For the health care of this sector, we need more newer, cheaper and effective biosimilars in the market. It becomes therefore important to understand the regulatory guidelines and steps to come up with more biosimilars for the existing population and also more information is mandatory for the practicing clinicians to translate these effectively into clinical practice.

  15. Spatial Interpolation.

    NARCIS (Netherlands)

    Stein, A.

    1991-01-01

    The theory and practical application of techniques of statistical interpolation are studied in this thesis, and new developments in multivariate spatial interpolation and the design of sampling plans are discussed. Several applications to studies in soil science are presented.Sampling s

  16. Stability of Self-Similar Spherical Accretion

    CERN Document Server

    Gaite, J

    2006-01-01

    Spherical accretion flows are simple enough for analytical study, by solution of the corresponding fluid dynamic equations. The solutions of stationary spherical flow are due to Bondi. The questions of the choice of a physical solution and of stability have been widely discussed. The answer to these questions is very dependent on the problem of boundary conditions, which vary according to whether the accretor is a compact object or a black hole. We introduce a particular, simple form of stationary spherical flow, namely, self-similar Bondi flow, as a case with physical interest in which analytic solutions for perturbations can be found. With suitable no matter-flux-perturbation boundary conditions, we will show that acoustic modes are stable in time and have no spatial instability at r=0. Furthermore, their evolution eventually becomes ergodic-like and shows no trace of instability or of acquiring any remarkable pattern.

  17. Explaining Spatial Homogamy. Compositional, Spatial and Regional Cultural Determinants of Regional Patterns of Spatial Homogamy in the Netherlands

    NARCIS (Netherlands)

    Haandrikman, Karen; van Wissen, Leo J. G.; Harmsen, Carel N.

    2011-01-01

    Spatial homogamy, or sharing a similarity in geographical origin, is an under-researched dimension in homogamy studies. In the Netherlands, people tend to choose spatially homogamous partners. Moreover, there is considerable regional variation in spatial homogamy, even when residential location and

  18. The potential of Cycloclasticus and Altererythrobacter strains for use in bioremediation of petroleum-aromatic-contaminated tropical marine environments.

    Science.gov (United States)

    Teramoto, Maki; Suzuki, Masahito; Hatmanti, Ariani; Harayama, Shigeaki

    2010-07-01

    Cycloclasticus sp. A5, which has been suggested to be a major degrader of petroleum aromatics spilled in temperate seas, showed higher degrading activities for petroleum aromatics, at both 25 degrees C and tropical sea temperature 30 degrees C, than the novel aromatic-degrading isolates, related to Altererythrobacter epoxidivorans (97.5% similarity in the almost full-length 16S rRNA gene sequence) and Rhodovulum iodosum (96.3% similarity), obtained after enrichment on crude oil in a continuous supply of Indonesian seawater. Cycloclasticus A5 degraded petroleum aromatics at a similar rate or faster at 30 degrees C as compared to 25 degrees C, but its growth on acetate was severely inhibited at 30 degrees C. These results suggest that, although their abundance would be low in tropical seas not contaminated with aromatics, the Cycloclasticus strains could be major degraders of petroleum aromatics spilled in tropical seas. The 16S rRNA gene of the Cycloclasticus strains has been identified from Indonesian seawater, and the gene fragments showed 96.7-96.8% similarities to that of Cycloclasticus A5. Introducing Cycloclasticus A5 may be an ecologically advantageous bioremediation strategy for petroleum-aromatic-contaminated tropical seas because strain A5 would disappear at 30 degrees C after complete consumption of the aromatics. Altererythrobacter and Rhodovulum-related isolates grew well on pyruvate in 10% strength marine broth at 30 degrees C whereas Cycloclasticus A5 did not grow well on acetate in the broth at 30 degrees C. These growth results, along with its petroleum-aromatic-degrading activity, suggest that the Altererythrobacter isolate could be an important petroleum-aromatic degrader in and around nutrient-rich tropical marine environments.

  19. Sequential Application of Soil Vapor Extraction and Bioremediation Processes for the Remediation of Ethylbenzene-Contaminated Soils

    DEFF Research Database (Denmark)

    Soares, António Carlos Alves; Pinho, Maria Teresa; Albergaria, José Tomás;

    2012-01-01

    Soil vapor extraction (SVE) is an efficient, well-known and widely applied soil remediation technology. However, under certain conditions it cannot achieve the defined cleanup goals, requiring further treatment, for example, through bioremediation (BR). The sequential application...

  20. LITERATURE REVIEW ON THE USE OF COMMERCIAL BIOREMEDIATION AGENTS FOR CLEAN-UP OF OIL-CONTAMINATED ESTUARINE ENVIRONMENTS

    Science.gov (United States)

    The objective of this document is to conduct a comprehensive review of the use of commercial bioremediation products treating oil spills in all environments, Literature assessed includes peer-reviewed articles, company reports, government reports, and reports by cleanup contracto...

  1. EFFECTIVENESS AND SAFETY OF STRATEGIES FOR OIL SPILL BIOREMEDIATION: POTENTIAL AND LIMITATION, LABORATORY TO FIELD (RESEARCH BRIEF)

    Science.gov (United States)

    Several important additional research efforts were identified during the development of test systems and protocols for assessing the effectiveness and environmental safety of oil spill commercial bioremediation agents (CBAs). Research that examined CBA efficacy issues included: (...

  2. Sparse Similarity-Based Fisherfaces

    DEFF Research Database (Denmark)

    Fagertun, Jens; Gomez, David Delgado; Hansen, Mads Fogtmann;

    2011-01-01

    In this work, the effect of introducing Sparse Principal Component Analysis within the Similarity-based Fisherfaces algorithm is examined. The technique aims at mimicking the human ability to discriminate faces by projecting the faces in a highly discriminative and easy interpretative way. Pixel...... obtain the same recognition results as the technique in a dense version using only a fraction of the input data. Furthermore, the presented results suggest that using SPCA in the technique offers robustness to occlusions....

  3. Self-similarity Driven Demosaicking

    Directory of Open Access Journals (Sweden)

    Antoni Buades

    2011-06-01

    Full Text Available Digital cameras record only one color component per pixel, red, green or blue. Demosaicking is the process by which one can infer a whole color matrix from such a matrix of values, thus interpolating the two missing color values per pixel. In this article we propose a demosaicking method based on the property of non-local self-similarity of images.

  4. Active browsing using similarity pyramids

    Science.gov (United States)

    Chen, Jau-Yuen; Bouman, Charles A.; Dalton, John C.

    1998-12-01

    In this paper, we describe a new approach to managing large image databases, which we call active browsing. Active browsing integrates relevance feedback into the browsing environment, so that users can modify the database's organization to suit the desired task. Our method is based on a similarity pyramid data structure, which hierarchically organizes the database, so that it can be efficiently browsed. At coarse levels, the similarity pyramid allows users to view the database as large clusters of similar images. Alternatively, users can 'zoom into' finer levels to view individual images. We discuss relevance feedback for the browsing process, and argue that it is fundamentally different from relevance feedback for more traditional search-by-query tasks. We propose two fundamental operations for active browsing: pruning and reorganization. Both of these operations depend on a user-defined relevance set, which represents the image or set of images desired by the user. We present statistical methods for accurately pruning the database, and we propose a new 'worm hole' distance metric for reorganizing the database, so that members of the relevance set are grouped together.

  5. Self-Similar Collisionless Shocks

    CERN Document Server

    Katz, B; Waxman, E; Katz, Boaz; Keshet, Uri; Waxman, Eli

    2006-01-01

    Observations of gamma-ray burst afterglows suggest that the correlation length of magnetic field fluctuations downstream of relativistic non-magnetized collisionless shocks grows with distance from the shock to scales much larger than the plasma skin depth. We argue that this indicates that the plasma properties are described by a self-similar solution, and derive constraints on the scaling properties of the solution. For example, we find that the scaling of the characteristic magnetic field amplitude with distance from the shock is B \\propto D^{s_B} with -1 \\propto x^{2s_B} (for x>>D). We show that the plasma may be approximated as a combination of two self-similar components: a kinetic component of energetic particles and an MHD-like component representing "thermal" particles. We argue that the latter may be considered as infinitely conducting, in which case s_B=0 and the scalings are completely determined (e.g. dn/dE \\propto E^{-2} and B \\propto D^0). Similar claims apply to non- relativistic shocks such a...

  6. Roget's Thesaurus and Semantic Similarity

    CERN Document Server

    Jarmasz, Mario

    2012-01-01

    We have implemented a system that measures semantic similarity using a computerized 1987 Roget's Thesaurus, and evaluated it by performing a few typical tests. We compare the results of these tests with those produced by WordNet-based similarity measures. One of the benchmarks is Miller and Charles' list of 30 noun pairs to which human judges had assigned similarity measures. We correlate these measures with those computed by several NLP systems. The 30 pairs can be traced back to Rubenstein and Goodenough's 65 pairs, which we have also studied. Our Roget's-based system gets correlations of .878 for the smaller and .818 for the larger list of noun pairs; this is quite close to the .885 that Resnik obtained when he employed humans to replicate the Miller and Charles experiment. We further evaluate our measure by using Roget's and WordNet to answer 80 TOEFL, 50 ESL and 300 Reader's Digest questions: the correct synonym must be selected amongst a group of four words. Our system gets 78.75%, 82.00% and 74.33% of ...

  7. Eliciting Public Attitudes Regarding Bioremediation Cleanup Technologies: Lessons Learned from a Consensus Workshop in Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Denise Lach, Principle Investigator; Stephanie Sanford, Co-P.I.

    2003-03-01

    During the summer of 2002, we developed and implemented a ''consensus workshop'' with Idaho citizens to elicit their concerns and issues regarding the use of bioremediation as a cleanup technology for radioactive nuclides and heavy metals at Department of Energy (DOE) sites. The consensus workshop is a derivation of a technology assessment method designed to ensure dialogue between experts and lay people. It has its origins in the United States in the form of ''consensus development conferences'' used by the National Institutes of Health (NIH) to elicit professional knowledge and concerns about new medical treatments. Over the last 25 years, NIH has conducted over 100 consensus development conferences. (Jorgensen 1995). The consensus conference is grounded in the idea that technology assessment and policy needs to be socially negotiated among many different stakeholders and groups rather than narrowly defined by a group of experts. To successfully implement new technology, the public requires access to information that addresses a full complement of issues including understanding the organization proposing the technology. The consensus conference method creates an informed dialogue, making technology understandable to the general public and sets it within perspectives and priorities that may differ radically from those of the expert community. While specific outcomes differ depending on the overall context of a conference, one expected outcome is that citizen panel members develop greater knowledge of the technology during the conference process and, sometimes, the entire panel experiences a change in attitude toward the technology and/or the organization proposing its use (Kluver 1995). The purpose of this research project was to explore the efficacy of the consensus conference model as a way to elicit the input of the general public about bioremediation of radionuclides and heavy metals at Department of Energy sites

  8. Bioremediation of CCA-Treated Wood By Brown-Rot Fungi Fomitopsis Palustris, Coniophora Puteana, and Laetiporus Sulphureus

    OpenAIRE

    Kartal, S Nami; Munir, Erman; Kamitani, Tomo

    2008-01-01

    This study evaluated oxalic acid accumulation and bioremediation of chromated copper arscnate (CCA)-treated wood by three brown-rot fungi Fomitopsis palustris Coniophora puteane, and Laetiporus sulphureas. The fungi were first cultivated in a fermentation broth to accumulate oxalic acid. Bioremediation of CCA-treated wood was then carried out by leaching of heavy metals with oxalic acid over a 10-day fermentation period. Higher amounts of oxalic acid were produced by F. polustris and L. sulp...

  9. Raw Materials Synthesis from Heavy Metal Industry Effluents with Bioremediation and Phytomining: A Biomimetic Resource Management Approach

    OpenAIRE

    Salmah B. Karman; S. Zaleha M. Diah; Ille C. Gebeshuber

    2015-01-01

    Heavy metal wastewater poses a threat to human life and causes significant environmental problems. Bioremediation provides a sustainable waste management technique that uses organisms to remove heavy metals from contaminated water through a variety of different processes. Biosorption involves the use of biomass, such as plant extracts and microorganisms (bacteria, fungi, algae, yeast), and represents a low-cost and environmentally friendly method of bioremediation and resource management. Bio...

  10. Spatial Culture

    DEFF Research Database (Denmark)

    Reeh, Henrik

    2012-01-01

    for re-subjectivization. By developing a dialogue with other disciplines, such as the conception of architecture outlined by Alberto Pérez-Gómez, humanistic urban studies may even contribute to reappropriations of objective culture. During the first decade of the 2000s, graduate students at the Faculty......Spatial Culture – A Humanities Perspective Abstract of introductory essay by Henrik Reeh Secured by alliances between socio-political development and cultural practices, a new field of humanistic studies in spatial culture has developed since the 1990s. To focus on links between urban culture...... and modern society is, however, an intellectual practice which has a much longer history. Already in the 1980s, the debate on the modern and the postmodern cited Paris and Los Angeles as spatio-cultural illustrations of these major philosophical concepts. Earlier, in the history of critical studies, the work...

  11. Spatial distribution

    DEFF Research Database (Denmark)

    Borregaard, Michael Krabbe; Hendrichsen, Ditte Katrine; Nachman, Gøsta Støger

    2008-01-01

    Living organisms are distributed over the entire surface of the planet. The distribution of the individuals of each species is not random; on the contrary, they are strongly dependent on the biology and ecology of the species, and vary over different spatial scale. The structure of whole...... populations reflects the location and fragmentation pattern of the habitat types preferred by the species, and the complex dynamics of migration, colonization, and population growth taking place over the landscape. Within these, individuals are distributed among each other in regular or clumped patterns......, depending on the nature of intraspecific interactions between them: while the individuals of some species repel each other and partition the available area, others form groups of varying size, determined by the fitness of each group member. The spatial distribution pattern of individuals again strongly...

  12. In situ groundwater and sediment bioremediation: barriers and perspectives at European contaminated sites.

    Science.gov (United States)

    Majone, Mauro; Verdini, Roberta; Aulenta, Federico; Rossetti, Simona; Tandoi, Valter; Kalogerakis, Nicolas; Agathos, Spiros; Puig, Sebastià; Zanaroli, Giulio; Fava, Fabio

    2015-01-25

    This paper contains a critical examination of the current application of environmental biotechnologies in the field of bioremediation of contaminated groundwater and sediments. Based on analysis of conventional technologies applied in several European Countries and in the US, scientific, technical and administrative barriers and constraints which still need to be overcome for an improved exploitation of bioremediation are discussed. From this general survey, it is evident that in situ bioremediation is a highly promising and cost-effective technology for remediation of contaminated soil, groundwater and sediments. The wide metabolic diversity of microorganisms makes it applicable to an ever-increasing number of contaminants and contamination scenarios. On the other hand, in situ bioremediation is highly knowledge-intensive and its application requires a thorough understanding of the geochemistry, hydrogeology, microbiology and ecology of contaminated soils, groundwater and sediments, under both natural and engineered conditions. Hence, its potential still remains partially unexploited, largely because of a lack of general consensus and public concerns regarding the lack of effectiveness and control, poor reliability, and possible occurrence of side effects, for example accumulation of toxic metabolites and pathogens. Basic, applied and pre-normative research are all needed to overcome these barriers and make in situ bioremediation more reliable, robust and acceptable to the public, as well as economically more competitive. Research efforts should not be restricted to a deeper understanding of relevant microbial reactions, but also include their interactions with the large array of other relevant phenomena, as a function of the truly variable site-specific conditions. There is a need for a further development and application of advanced biomolecular tools for site investigation, as well as of advanced metabolic and kinetic modelling tools. These would allow a

  13. Germination and initial growth of Campomanesia xanthocarpa O. Berg. (Myrtaceae), in petroleum-contaminated soil and bioremediated soil.

    Science.gov (United States)

    Gogosz, A M; Bona, C; Santos, G O; Botosso, P C

    2010-11-01

    In 2000 there was an oil spill at the Getúlio Vargas Refinery (REPAR) in Paraná. Nearly five years after contamination and the use of bioremediation, a study was carried out to identify the effects of the contaminated soil and the bioremediated soil on the germination and initial growth of C. xanthocarpa. The experiment was established with soil from REPAR, with three treatment groups: contaminated soil (C), bioremediated soil (B) and uncontaminated soil (U); with five repetitions of 50 seeds each. There was no significant difference in the percentage of germination and the speed of germination index. The production of total biomass (30 - 60 days) and shoot biomass (60 days) was greater in the bioremediated soil compared to the other treatments. The averages for the root biomass were lower in the contaminated soil than in the bioremediated soil. The shoot length and the total length of the seedling in the contaminated soil and uncontaminated soil were lower than in the bioremediated soil.

  14. Germination and initial growth of Campomanesia xanthocarpa O. Berg. (Myrtaceae, in petroleum-contaminated soil and bioremediated soil

    Directory of Open Access Journals (Sweden)

    AM. Gogosz

    Full Text Available In 2000 there was an oil spill at the Getúlio Vargas Refinery (REPAR in Paraná. Nearly five years after contamination and the use of bioremediation, a study was carried out to identify the effects of the contaminated soil and the bioremediated soil on the germination and initial growth of C. xanthocarpa. The experiment was established with soil from REPAR, with three treatment groups: contaminated soil (C, bioremediated soil (B and uncontaminated soil (U; with five repetitions of 50 seeds each. There was no significant difference in the percentage of germination and the speed of germination index. The production of total biomass (30 - 60 days and shoot biomass (60 days was greater in the bioremediated soil compared to the other treatments. The averages for the root biomass were lower in the contaminated soil than in the bioremediated soil. The shoot length and the total length of the seedling in the contaminated soil and uncontaminated soil were lower than in the bioremediated soil.

  15. Assessing protein kinase target similarity

    DEFF Research Database (Denmark)

    Gani, Osman A; Thakkar, Balmukund; Narayanan, Dilip

    2015-01-01

    : focussed chemical libraries, drug repurposing, polypharmacological design, to name a few. Protein kinase target similarity is easily quantified by sequence, and its relevance to ligand design includes broad classification by key binding sites, evaluation of resistance mutations, and the use of surrogate......" of sequence and crystal structure information, with statistical methods able to identify key correlates to activity but also here, "the devil is in the details." Examples from specific repurposing and polypharmacology applications illustrate these points. This article is part of a Special Issue entitled...

  16. Monitoring system for the study of autotrophic biofilms in bioremediation of polyaromatic compounds

    Science.gov (United States)

    Alarie, Jean P.; Bruttig, A.; Miller, Gordon H.; Hill, Walter; Vo-Dinh, Tuan

    1999-02-01

    Bacterial and other natural materials such as plants and algae have received increasing interest for bioremediation efforts. The identificatIon of materials capable of biodegrading or sequestering environmental pollutants offers an attractive alternative to chemical or physical means of remediation. A number of bacteria capable of biodegrAding organic or reducing metal pollutants have received great interest. Similarly, the use of natural plants to absorb pollutants from soil anD liquid samples is another potential approach. Our interest lies in identification of naturally occurring algae and their ability to absorb polyaromatic compounds (PAC) from groundwater sources (i.e. streams). These algae could serve as natural water filters for streams contaminated with Polyaromatic hydrocarbons. Polycyclic aromatic compounds, which comprise a complex class of condensed multi-ring benzenoid compounds, are important environmental pollutants originating from a wide variety of natural and anthropogenic sources. PACs are generally formed during incomplete combustion or pyrolysis of organic matter containing carbon and hydrogen. Because combustion of organic materials is involved in countless natural processes or human activities, PACs are omnipresent and abundant pollutants in air, soil and water. Among energy-related products, fossil fuels are the major sources of PACs. The primary sources of airborne PACs are associated with combustion, coal coking, and petroleum catalytic cracking. Coal and shale conversion also contribute to production of PACs. Production, transportation and, use of synthetic fuels and petroleum products provide emission sources for PACs. In urban environments an significant source of PACs is diesel exhaust. Food cooking and cigarette smoking activities contribute to PAC occurrence in indoor environments. Chemical analysis of PACs is of great environmental and toxicological interest because many of them have been shown to be mutagens and/or potent

  17. Solarization and biosolarization using organic wastes for the bioremediation of soil polluted with terbuthylazine and linuron residues.

    Science.gov (United States)

    Fenoll, José; Hellín, Pilar; Flores, Pilar; Lacasa, Alfredo; Navarro, Simón

    2014-10-01

    Strategies for remediation of polluted soils are needed to accelerate the degradation and natural attenuation of pesticides. This study was conducted to assess the effect of solarization (S) and biosolarization (BS) during the summer season using organic wastes (composted sheep manure and sugar beet vinasse) for the bioremediation of soil containing residues of terbuthylazine and linuron. The results showed that both S and BS enhanced herbicide dissipation rates compared with the non-disinfected control, an effect which was attributed to the increased soil temperature and organic matter. Linuron showed similar behavior under S and BS conditions. However, terbuthylazine was degraded to a greater extent in the biosolarization experiment using sugar beet vinasse than in the both the solarization and biosolarization experiments using composted sheep manure treatments. The main organic intermediates detected during the degradation of terbuthylazine and linuron were identified, enabling the main steps of degradation to be proposed. The results confirm that both S and BS techniques can be considered as a remediation tools for polluted soils containing these herbicides.

  18. Enhanced Bioremediation of Soil Artificially Contaminated with Petroleum Hydrocarbons after Amendment with Capra aegagrus hircus (Goat Manure

    Directory of Open Access Journals (Sweden)

    T. P. Nwogu

    2015-01-01

    Full Text Available This study was carried out to evaluate the biostimulant potentials of Capra aegagrus hircus manure for bioremediation of crude oil contaminated soil (COCS under tropical conditions. 1 kg of COCS sample was amended with 0.02 kg of C. a. hircus manure and monitored at 14-day intervals for total petroleum hydrocarbon (TPH, nutrient content, and changes in microbial counts. At the end of the study period, there was 62.08% decrease in the concentration of TPH in the amended sample compared to 8.15% decrease in the unamended sample, with significant differences (P<0.05 in TPH concentrations for both samples at different time intervals. Similarly, there was a gradual decrease in the concentrations of total organic carbon, nitrogen, phosphorus, and potassium in both samples. The culturable hydrocarbon-utilizing bacteria (CHUB increased steadily from 8.5 × 105 cfu/g to 2.70 × 106 cfu/g and from 8.0 × 105 cfu/g to 1.78 × 106 cfu/g for both samples. Acinetobacter, Achromobacter, Bacillus, Flavobacterium, Klebsiella, Micrococcus, Pseudomonas, and Staphylococcus were isolated from amended sample with Pseudomonas being the predominant isolated bacterial genus. This study demonstrated that C. a. hircus manure is a good biostimulant, which enhanced the activities of indigenous hydrocarbonoclastic bacteria resulting in significant decrease in TPH concentration of COCS.

  19. Microbiological characteristics of multi-media PRB reactor in the bioremediation of groundwater contaminated by petroleum hydrocarbons.

    Science.gov (United States)

    Liu, Hong; Zhang, Lanying; Deng, Haijing; Liu, Na; Liu, Cuizhu

    2011-10-01

    A multi-media bio-PRB reactor was designed to treat groundwater contaminated with petroleum hydrocarbons. After a 208-day bioremediation, combined with the total petroleum hydrocarbons content in the groundwater flowed through the reactor, microbiological characteristics of the PRB reactor including microbes immobilized and its dehydrogenase activity were investigated. TPH was significantly reduced by as much as 65% in the back of the second media layer, whereas in the third layer, the TPH content reached lower than 1 mg l⁻¹. For microbes immobilized on the media, the variations with depth in different media were significantly the same and the regularity was obvious in the forepart of the media, which increased with depth at first and then reduced gradually, while in the back-end, the microbes almost did not have any variations with depth but decreased with the distance. The dehydrogenase activity varied from 2.98 to 16.16 mg TF L⁻¹ h⁻¹ and its distribution illustrated a similar trend with numbers of microbial cell, therefore, the noticeable correlation was found between them.

  20. Mechanisms for similarity based cooperation

    Science.gov (United States)

    Traulsen, A.

    2008-06-01

    Cooperation based on similarity has been discussed since Richard Dawkins introduced the term “green beard” effect. In these models, individuals cooperate based on an aribtrary signal (or tag) such as the famous green beard. Here, two different models for such tag based cooperation are analysed. As neutral drift is important in both models, a finite population framework is applied. The first model, which we term “cooperative tags” considers a situation in which groups of cooperators are formed by some joint signal. Defectors adopting the signal and exploiting the group can lead to a breakdown of cooperation. In this case, conditions are derived under which the average abundance of the more cooperative strategy exceeds 50%. The second model considers a situation in which individuals start defecting towards others that are not similar to them. This situation is termed “defective tags”. It is shown that in this case, individuals using tags to cooperate exclusively with their own kind dominate over unconditional cooperators.

  1. Impact of bacterial activity on turnover of insoluble hydrophobic substrates (phenanthrene and pyrene)—Model simulations for prediction of bioremediation success

    DEFF Research Database (Denmark)

    Rein, Arno; Adam, Iris K.U.; Miltner, Anja

    2016-01-01

    Many attempts for bioremediation of polycyclic aromatic hydrocarbon (PAH) contaminated sites failed in the past, but the reasons for this failure are not well understood. Here we apply and improve a model for integrated assessment of mass transfer, biodegradation and residual concentrations...... for predicting the success of remediation actions. First, we provide growth parameters for Mycobacterium rutilum and Mycobacterium pallens growing on phenanthrene (PHE) or pyrene (PYR) degraded the PAH completely at all investigated concentrations. Maximum metabolic rates vmax and growth rates μ were similar...... a small, short-lived effect; (ii) Increasing sorption shifts the remaining PAH to the adsorbed/sequestered PAH pool; (iii) mobilizing by solvents or surfactants resulted in a significant decrease of the sequestered PAH, and (iv) co-metabolization e.g. by compost addition can contribute significantly...

  2. Monitoring of ground water quality and heavy metals in soil during large scale bioremediation of petroleum hydrocarbon contaminated waste in India: case studies

    OpenAIRE

    Ajoy Kumar Mandal; Atanu Jana; Mr. Abhijit Datta; Sarma, Priyangshu M.; Banwari Lal; Jayati Datta

    2014-01-01

    Bioremediation using microbes has been well accepted as an environmentally friendly and economical treatment method for disposal of hazardous petroleum hydrocarbon contaminated waste (oily waste) and this type of bioremediation has been successfully conducted in laboratory and on a pilot scale in various countries, including India. Presently there are no federal regulatory guidelines available in India for carrying out field-scale bioremediation of oily waste using microbes. The results of th...

  3. Interneurons targeting similar layers receive synaptic inputs with similar kinetics.

    Science.gov (United States)

    Cossart, Rosa; Petanjek, Zdravko; Dumitriu, Dani; Hirsch, June C; Ben-Ari, Yehezkel; Esclapez, Monique; Bernard, Christophe

    2006-01-01

    GABAergic interneurons play diverse and important roles in controlling neuronal network dynamics. They are characterized by an extreme heterogeneity morphologically, neurochemically, and physiologically, but a functionally relevant classification is still lacking. Present taxonomy is essentially based on their postsynaptic targets, but a physiological counterpart to this classification has not yet been determined. Using a quantitative analysis based on multidimensional clustering of morphological and physiological variables, we now demonstrate a strong correlation between the kinetics of glutamate and GABA miniature synaptic currents received by CA1 hippocampal interneurons and the laminar distribution of their axons: neurons that project to the same layer(s) receive synaptic inputs with similar kinetics distributions. In contrast, the kinetics distributions of GABAergic and glutamatergic synaptic events received by a given interneuron do not depend upon its somatic location or dendritic arborization. Although the mechanisms responsible for this unexpected observation are still unclear, our results suggest that interneurons may be programmed to receive synaptic currents with specific temporal dynamics depending on their targets and the local networks in which they operate.

  4. The Gestalt principle of similarity benefits visual working memory.

    Science.gov (United States)

    Peterson, Dwight J; Berryhill, Marian E

    2013-12-01

    Visual working memory (VWM) is essential for many cognitive processes, yet it is notably limited in capacity. Visual perception processing is facilitated by Gestalt principles of grouping, such as connectedness, similarity, and proximity. This introduces the question, do these perceptual benefits extend to VWM? If so, can this be an approach to enhance VWM function by optimizing the processing of information? Previous findings have demonstrated that several Gestalt principles (connectedness, common region, and spatial proximity) do facilitate VWM performance in change detection tasks (Jiang, Olson, & Chun, 2000; Woodman, Vecera, & Luck, 2003; Xu, 2002, 2006; Xu & Chun, 2007). However, one prevalent Gestalt principle, similarity, has not been examined with regard to facilitating VWM. Here, we investigated whether grouping by similarity benefits VWM. Experiment 1 established the basic finding that VWM performance could benefit from grouping. Experiment 2 replicated and extended this finding by showing that similarity was only effective when the similar stimuli were proximal. In short, the VWM performance benefit derived from similarity was constrained by spatial proximity, such that similar items need to be near each other. Thus, the Gestalt principle of similarity benefits visual perception, but it can provide benefits to VWM as well.

  5. The Spatial Politics of Spatial Representation

    DEFF Research Database (Denmark)

    Olesen, Kristian; Richardson, Tim

    2011-01-01

    This paper explores the interplay between the spatial politics of new governance landscapes and innovations in the use of spatial representations in planning. The central premise is that planning experiments with new relational approaches become enmeshed in spatial politics. The case of strategic...... spatial planning in Denmark reveals how fuzzy spatial representations and relational spatial concepts are being used to depoliticise strategic spatial planning processes and to camouflage spatial politics. The paper concludes that, while relational geography might play an important role in building...... consensus, it plays an equal important role in supporting current neoliberal transformations of strategic spatial planning....

  6. Performance Indexes: Similarities and Differences

    Directory of Open Access Journals (Sweden)

    André Machado Caldeira

    2013-06-01

    Full Text Available The investor of today is more rigorous on monitoring a financial assets portfolio. He no longer thinks only in terms of the expected return (one dimension, but in terms of risk-return (two dimensions. Thus new perception is more complex, since the risk measurement can vary according to anyone’s perception; some use the standard deviation for that, others disagree with this measure by proposing others. In addition to this difficulty, there is the problem of how to consider these two dimensions. The objective of this essay is to study the main performance indexes through an empirical study in order to verify the differences and similarities for some of the selected assets. One performance index proposed in Caldeira (2005 shall be included in this analysis.

  7. Semantically enabled image similarity search

    Science.gov (United States)

    Casterline, May V.; Emerick, Timothy; Sadeghi, Kolia; Gosse, C. A.; Bartlett, Brent; Casey, Jason

    2015-05-01

    Georeferenced data of various modalities are increasingly available for intelligence and commercial use, however effectively exploiting these sources demands a unified data space capable of capturing the unique contribution of each input. This work presents a suite of software tools for representing geospatial vector data and overhead imagery in a shared high-dimension vector or embedding" space that supports fused learning and similarity search across dissimilar modalities. While the approach is suitable for fusing arbitrary input types, including free text, the present work exploits the obvious but computationally difficult relationship between GIS and overhead imagery. GIS is comprised of temporally-smoothed but information-limited content of a GIS, while overhead imagery provides an information-rich but temporally-limited perspective. This processing framework includes some important extensions of concepts in literature but, more critically, presents a means to accomplish them as a unified framework at scale on commodity cloud architectures.

  8. SIMILARITIES AND DIFFERENCES BETWEEN COMPANIES

    Directory of Open Access Journals (Sweden)

    NAGY CRISTINA MIHAELA

    2015-05-01

    Full Text Available act: Similarities between the accounting of companies and territorial administrative units accounting are the following: organizing double entry accounting; accounting method both in terms of fundamental theoretical principles and specific practical tools. The differences between the accounting of companies and of territorial administrative units refer to: the accounting of territorial administrative units includes besides general accounting (financial also budgetary accounting, and the accounts system of the budgetary accounting is completely different from that of companies; financial statements of territorial administrative units to which leaders are not main authorizing officers are submitted to the hierarchically superior body (not at MPF; the accounts of territorial administrative units are opened at treasury and financial institutions, accounts at commercial banks being prohibited; equity accounts in territorial administrative units are structured into groups of funds; long term debts have a specific structure in territorial administrative units (internal local public debt and external local public debt.

  9. Features Based Text Similarity Detection

    CERN Document Server

    Kent, Chow Kok

    2010-01-01

    As the Internet help us cross cultural border by providing different information, plagiarism issue is bound to arise. As a result, plagiarism detection becomes more demanding in overcoming this issue. Different plagiarism detection tools have been developed based on various detection techniques. Nowadays, fingerprint matching technique plays an important role in those detection tools. However, in handling some large content articles, there are some weaknesses in fingerprint matching technique especially in space and time consumption issue. In this paper, we propose a new approach to detect plagiarism which integrates the use of fingerprint matching technique with four key features to assist in the detection process. These proposed features are capable to choose the main point or key sentence in the articles to be compared. Those selected sentence will be undergo the fingerprint matching process in order to detect the similarity between the sentences. Hence, time and space usage for the comparison process is r...

  10. Role of microbial enzymes in the bioremediation of pollutants: a review.

    Science.gov (United States)

    Karigar, Chandrakant S; Rao, Shwetha S

    2011-01-01

    A large number of enzymes from bacteria, fungi, and plants have been reported to be involved in the biodegradation of toxic organic pollutants. Bioremediation is a cost effective and nature friendly biotechnology that is powered by microbial enzymes. The research activity in this area would contribute towards developing advanced bioprocess technology to reduce the toxicity of the pollutants and also to obtain novel useful substances. The information on the mechanisms of bioremediation-related enzymes such as oxido-reductases and hydrolases have been extensively studied. This review attempts to provide descriptive information on the enzymes from various microorganisms involved in the biodegradation of wide range of pollutants, applications, and suggestions required to overcome the limitations of their efficient use.

  11. Microbial-electrochemical bioremediation and detoxification of dibenzothiophene-polluted soil.

    Science.gov (United States)

    Rodrigo, Jose; Boltes, Karina; Esteve-Nuñez, Abraham

    2014-04-01

    Bioremediation is a relatively efficient and cost-effective technology for treating polluted soils. However, the availability of suitable electron acceptors to sustain microbial respiration can reduce the microbial activity. This work aims to evaluate the impact of burying electrically conductive electron acceptors in soil for enhancing the removal of dibenzothiophene (DBT) by native electrogenic microbes. Although this novel approach is based on the use of a microbial electrochemical technology as microbial fuel cells, our goal is not to harvest energy but to maximize bioremediation, so we concluded to name the device as Microbial Electroremediating Cell (MERC). Our results proved that stimulating the microbial electrogenic metabolism, DBT removal was enhanced by more than 3-fold compared to the natural attenuation. On top of that, ecotoxicological test using green algae confirms a decrease of 50% in the toxicity of the treated soil during incubation in MERC, in contrast to the unaltered values detected under natural conditions.

  12. The Influence of Soil Chemical Factors on In Situ Bioremediation of Soil Contamination

    Energy Technology Data Exchange (ETDEWEB)

    Breedveld, Gijs D.

    1997-12-31

    Mineral oil is the major energy source in Western society. Production, transport and distribution of oil and oil products cause serious contamination problems of water, air and soil. The present thesis studies the natural biodegradation processes in the soil environment which can remove contamination by oil products and creosote. The main physical/chemical processes determining the distribution of organic contaminants between the soil solid, aqueous and vapour phase are discussed. Then a short introduction to soil microbiology and environmental factors important for biodegradation is given. There is a discussion of engineered and natural bioremediation methods and the problems related to scaling up laboratory experiments to field scale remediation. Bioremediation will seldom remove the contaminants completely; a residue remains. Factors affecting the level of residual contamination and the consequences for contaminant availability are discussed. Finally, the main findings of the work are summarized and recommendations for further research are given. 111 refs., 41 figs., 19 tabs.

  13. Biological sand filters: low-cost bioremediation technique for production of clean drinking water.

    Science.gov (United States)

    Lea, Michael

    2008-05-01

    Approximately 1.1 billion people in rural and peri-urban communities of developing countries do not have access to safe drinking water. The mortality from diarrheal-related diseases amounts to approximately 2.2 million people each year from the consumption of unsafe water. Most of them are children under 5 years of age-250 deaths an hour from microbiologically contaminated water. There is conclusive evidence that one low-cost household bioremediation intervention, biological sand filters, are capable of dramatically improving the microbiological quality of drinking water. This unit will describe this relatively new and proven bioremediation technology's ability to empower at-risk populations to use naturally occurring biology and readily available materials as a sustainable way to achieve the health benefits of safe drinking water.

  14. Ecosystem protection by effluent bioremediation: silver nanoparticles impregnation in a textile fabrics process

    Energy Technology Data Exchange (ETDEWEB)

    Duran, Nelson, E-mail: duran@iqm.unicamp.br; Marcato, Priscyla D. [Universidade Estadual de Campinas, Biological Chemistry Laboratory, Instituto de Quimica (Brazil); Alves, Oswaldo L. [Universidade Estadual de Campinas, Solid State Chemistry Laboratory, Instituto de Quimica (Brazil); Silva, Joao P. S. Da; Souza, Gabriel I. H. De [Universidade de Mogi das Cruzes, Biological Chemistry and Biotechnology Laboratory, Environmental Sciences Center (Brazil); Rodrigues, Flavio A. [Universidade de Mogi das Cruzes, Material Chemistry Laboratory, Biochemical Research Center (Brazil); Esposito, Elisa [Universidade de Mogi das Cruzes, Biological Chemistry and Biotechnology Laboratory, Environmental Sciences Center (Brazil)

    2010-01-15

    This work studied a bioremediation process of silver nanoparticles with the bacterium Chromobacterium violaceum. These nanoparticles were obtained from several washes of cotton fabrics impregnated with silver nanoparticles produced by the fungus Fusarium oxysporum. The optimized growth of C. violaceum for silver nanoparticles bioremediation was obtained. The effluents of wash process of the cotton fabric were efficiently treated with C. violaceum. This treatment was based on biosorption which was very efficient for the elimination of silver nanoparticles remaining in the wash water. The bacteria after biosorption were morphologically transformed, but the normal morphology after a new culture was completely restored. The process also allowed the recovery of silver material that was leached into the effluent for a reutilization avoiding any effect to the eco-environment.

  15. Role of Microbial Enzymes in the Bioremediation of Pollutants: A Review

    Directory of Open Access Journals (Sweden)

    Chandrakant S. Karigar

    2011-01-01

    Full Text Available A large number of enzymes from bacteria, fungi, and plants have been reported to be involved in the biodegradation of toxic organic pollutants. Bioremediation is a cost effective and nature friendly biotechnology that is powered by microbial enzymes. The research activity in this area would contribute towards developing advanced bioprocess technology to reduce the toxicity of the pollutants and also to obtain novel useful substances. The information on the mechanisms of bioremediation-related enzymes such as oxido-reductases and hydrolases have been extensively studied. This review attempts to provide descriptive information on the enzymes from various microorganisms involved in the biodegradation of wide range of pollutants, applications, and suggestions required to overcome the limitations of their efficient use.

  16. Bioremediation of organic solvents in ground water: A case study--Grandview, Missouri

    Energy Technology Data Exchange (ETDEWEB)

    Humenik, J.A. (American Compliance Technologies, Inc., Lakeland, FL (United States))

    1993-10-01

    Organic solvents leaking from underground storage tanks or from spillage pose a serious threat to ground-water quality. Chemicals such as styrene, ethylbenzene, toluene, and methyl-methacrylate are commonly associated with the manufacturing of plastics and fiberglass. After pump-and-treat operations were unsuccessful in remediating ground water contaminated with ethylbenzene and styrene resulting from leaking underground chemical storage tanks, bioremediation was implemented to degrade the contaminants to the Missouri Department of Natural Resources target cleanup limits. Due to low permeability clays and anaerobic subsurface conditions, the bioremediation design consisted of a ground-water recovery system, an aboveground bioreactor to treat ground water, and a recharge network to introduce acclimated microbes, nutrients, and oxygen to the subsurface. Commercially prepared microbial strains and nutrients were utilized for the close-loop system, as insufficient indigenous microbes and nutrients were present in subsurface matrix.

  17. Molecular tools to understand the bioremediation effect of plants and earthworms on contaminated marine sediments.

    Science.gov (United States)

    Moreno, Beatriz; Cañizares, Rosa; Macci, Cristina; Doni, Serena; Masciandaro, Grazia; Benitez, Emilio

    2015-12-30

    A meso-scale pilot plant was set up to test the efficiency of a bioremediation scheme applied to marine sediments contaminated by heavy metals and hydrocarbons. The experiment was implemented for three years in two stages using two remediation agents: plants (Paspalum vaginatum and Tamarix gallica) and earthworms (Eisenia fetida). DNA and RNA-based methodologies were applied to elucidate the dynamics of the bacterial population and were related to improving biological and chemical conditions of the sediments. Bioremediation strategies were successful in removing pollutants from the contaminated sediments and specialization within the bacterial community related to the type of contamination present was detected in the different stages of the process. The highest response of Gram-positive PAH-degraders to the contamination was detected at the beginning and after the first stage of the experiment, corresponding to the uppermost values of degradation.

  18. Bioremediation via Methanotrophy: Overview of Recent Findings and Suggestions for Future Research

    Directory of Open Access Journals (Sweden)

    Jeremy eSemrau

    2011-10-01

    Full Text Available Microbially-mediated bioremediation of polluted sites has been a subject of much research over the past 30 years, with many different compounds shown to be degraded under both aerobic and anaerobic conditions. Aerobic-mediated bioremediation commonly examines the use of methanotrophs, microorganisms that consume methane as their sole source of carbon and energy. Given the diverse environments in which methanotrophs have been found, the range of substrates they can degrade and the fact that they can be easily stimulated with the provision of methane and oxygen, these microorganisms in particular have been examined for aerobic degradation of chlorinated hydrocarbons. The physiological and phylogenetic diversity of methanotrophy, however, has increased substantially in just the past five years. Here in this review, the current state of knowledge of methanotrophy, particularly as it applies to pollutant degradation is summarized, and suggestions for future research provided.

  19. Potential of non-ligninolytic fungi in bioremediation of chlorinated and polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Marco-Urrea, Ernest; García-Romera, Inmaculada; Aranda, Elisabet

    2015-12-25

    In previous decades, white-rot fungi as bioremediation agents have been the subjects of scientific research due to the potential use of their unspecific oxidative enzymes. However, some non-white-rot fungi, mainly belonging to the Ascomycota and Zygomycota phylum, have demonstrated their potential in the enzymatic transformation of environmental pollutants, thus overcoming some of the limitations observed in white-rot fungi with respect to growth in neutral pH, resistance to adverse conditions and the capacity to surpass autochthonous microorganisms. Despite their presence in so many soil and water environments, little information exists on the enzymatic mechanisms and degradation pathways involved in the transformation of hydrocarbons by these fungi. This review describes the bioremediation potential of non-ligninolytic fungi with respect to chlorinated hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) and also shows known conversion pathways and the prospects for future research.

  20. High bacterial biodiversity increases degradation performance of hydrocarbons during bioremediation of contaminated harbor marine sediments.

    Science.gov (United States)

    Dell'Anno, Antonio; Beolchini, Francesca; Rocchetti, Laura; Luna, Gian Marco; Danovaro, Roberto

    2012-08-01

    We investigated changes of bacterial abundance and biodiversity during bioremediation experiments carried out on oxic and anoxic marine harbor sediments contaminated with hydrocarbons. Oxic sediments, supplied with inorganic nutrients, were incubated in aerobic conditions at 20 °C and 35 °C for 30 days, whereas anoxic sediments, amended with organic substrates, were incubated in anaerobic conditions at the same temperatures for 60 days. Results reported here indicate that temperature exerted the main effect on bacterial abundance, diversity and assemblage composition. At higher temperature bacterial diversity and evenness increased significantly in aerobic conditions, whilst decreased in anaerobic conditions. In both aerobic and anaerobic conditions, biodegradation efficiencies of hydrocarbons were significantly and positively related with bacterial richness and evenness. Overall results presented here suggest that bioremediation strategies, which can sustain high levels of bacterial diversity rather than the selection of specific taxa, may significantly increase the efficiency of hydrocarbon degradation in contaminated marine sediments.

  1. Downscaling the in vitro test of fungal bioremediation of polycyclic aromatic hydrocarbons: methodological approach.

    Science.gov (United States)

    Drevinskas, Tomas; Mickienė, Rūta; Maruška, Audrius; Stankevičius, Mantas; Tiso, Nicola; Mikašauskaitė, Jurgita; Ragažinskienė, Ona; Levišauskas, Donatas; Bartkuvienė, Violeta; Snieškienė, Vilija; Stankevičienė, Antanina; Polcaro, Chiara; Galli, Emanuela; Donati, Enrica; Tekorius, Tomas; Kornyšova, Olga; Kaškonienė, Vilma

    2016-02-01

    The miniaturization and optimization of a white rot fungal bioremediation experiment is described in this paper. The optimized procedure allows determination of the degradation kinetics of anthracene. The miniaturized procedure requires only 2.5 ml of culture medium. The experiment is more precise, robust, and better controlled comparing it to classical tests in flasks. Using this technique, different parts, i.e., the culture medium, the fungi, and the cotton seal, can be analyzed. A simple sample preparation speeds up the analytical process. Experiments performed show degradation of anthracene up to approximately 60% by Irpex lacteus and up to approximately 40% by Pleurotus ostreatus in 25 days. Bioremediation of anthracene by the consortium of I. lacteus and P. ostreatus shows the biodegradation of anthracene up to approximately 56% in 23 days. At the end of the experiment, the surface tension of culture medium decreased comparing it to the blank, indicating generation of surfactant compounds.

  2. Bioremediation of PAH-contaminated soil by composting: a case study.

    Science.gov (United States)

    Cajthaml, T; Bhatt, M; Sasek, V; Matĕjů, V

    2002-01-01

    Composting technique was used for bioremediation of industrial soil originating from a former tar-contaminated site. The composting process was regulated by aeration to keep optimal temperature gradient and concentrations of O2 and CO2 inside the composting pile. The efficiency of bioremediation was evaluated by performing analysis of 11 individual three- to six-ring unsubstituted aromatic hydrocarbons (PAH) and estimating of changes in ecotoxicity of the contaminated soil. After 42 d of composting, PAH with 3-4 rings were removed from 42 to 68%, other higher-molar mass PAH from 35 to 57%. Additional 100 d of compost maturation in open-air field did not result in a further decrease of PAH. Ecotoxicity tests performed with bioluminescent bacteria Vibrio fischerii showed a decrease in toxicity both after composting and maturation phases. However, toxicity tests on mustard-seed germination did not reveal any significant changes during composting and maturation phases.

  3. In situ study of tetrachloroethylene bioremediation with different microbial community shifting.

    Science.gov (United States)

    Bhowmik, Arpita; Asahino, Akane; Shiraki, Takanori; Nakamura, Kohei; Takamizawa, Kazuhiro

    2009-12-14

    In this study, we characterized the microbial community in groundwater contaminated with tetrachloroethylene (PCE) in order to evaluate the intrinsic and enhanced bioremediation of PCE. Variable behaviour of microbes was observed between natural attenuation and biostimulation, where the latter was mediated by the addition of nutrients. Results of denaturing gradient gel electrophoresis (DGGE) of amplified bacterial 16S rDNA in the case of biostimulation showed that the microbial community was dominated by species phylogenetically related to the beta-proteobacteria. With regards to natural attenuation, sequences were found belonging to multiple species of different phyla. Interestingly, we found sequences that matched the species belonging to the Firmicutes, which contains bacteria capable of reductive dehalogenation. These results suggest the possibility of the presence of some Clostridium-like PCE degraders within the microbial community when using bioremediation or biostimulation.

  4. Enhancing pesticide degradation using indigenous microorganisms isolated under high pesticide load in bioremediation systems with vermicomposts.

    Science.gov (United States)

    Castillo Diaz, Jean Manuel; Delgado-Moreno, Laura; Núñez, Rafael; Nogales, Rogelio; Romero, Esperanza

    2016-08-01

    In biobed bioremediation systems (BBSs) with vermicomposts exposed to a high load of pesticides, 6 bacteria and 4 fungus strains were isolated, identified, and investigated to enhance the removal of pesticides. Three different mixtures of BBSs composed of vermicomposts made from greenhouse (GM), olive-mill (OM) and winery (WM) wastes were contaminated, inoculated, and incubated for one month (GMI, OMI and WMI). The inoculums maintenance was evaluated by DGGE and Q-PCR. Pesticides were monitored by HPLC-DAD. The highest bacterial and fungal abundance was observed in WMI and OMI respectively. In WMI, the consortia improved the removal of tebuconazole, metalaxyl, and oxyfluorfen by 1.6-, 3.8-, and 7.7-fold, respectively. The dissipation of oxyfluorfen was also accelerated in OMI, with less than 30% remaining after 30d. One metabolite for metalaxyl and 4 for oxyfluorfen were identified by GC-MS. The isolates could be suitable to improve the efficiency of bioremediation systems.

  5. Bioremediation of pesticide-contaminated water resources: the challenge of low concentrations.

    Science.gov (United States)

    Helbling, Damian E

    2015-06-01

    The use of pesticides in agricultural and urban environments has improved quality of life around the world. However, the resulting accumulation of pesticide residues in fresh water resources has negative effects on aquatic ecosystem and human health. Bioremediation has been proposed as an environmentally sound alternative for the remediation of pesticide-contaminated water resources, though full-scale implementation has thus far been limited. One major challenge that has impeded progress is the occurrence of pesticides at low concentrations. Recent research has improved our fundamental understanding of pesticide biodegradation processes occurring at low concentrations under a variety of environmental scenarios and is expected to contribute to the development of applied bioremediation strategies for pesticide-contaminated water resources.

  6. Biofilm lifestyle enhances diesel bioremediation and biosurfactant production in the Antarctic polyhydroxyalkanoate producer Pseudomonas extremaustralis.

    Science.gov (United States)

    Tribelli, Paula M; Di Martino, Carla; López, Nancy I; Raiger Iustman, Laura J

    2012-09-01

    Diesel is a widely distributed pollutant. Bioremediation of this kind of compounds requires the use of microorganisms able to survive and adapt to contaminated environments. Pseudomonas extremaustralis is an Antarctic bacterium with a remarkable survival capability associated to polyhydroxyalkanoates (PHAs) production. This strain was used to investigate the effect of cell growth conditions--in biofilm versus shaken flask cultures--as well as the inocula characteristics associated with PHAs accumulation, on diesel degradation. Biofilms showed increased cell growth, biosurfactant production and diesel degradation compared with that obtained in shaken flask cultures. PHA accumulation decreased biofilm cell attachment and enhanced biosurfactant production. Degradation of long-chain and branched alkanes was observed in biofilms, while in shaken flasks only medium-chain length alkanes were degraded. This work shows that the PHA accumulating bacterium P. extremaustralis can be a good candidate to be used as hydrocarbon bioremediation agent, especially in extreme environments.

  7. In silico Analysis for Laccase-mediated Bioremediation of the Emerging Pharmaceutical Pollutants

    Directory of Open Access Journals (Sweden)

    Anjali Singh

    2015-12-01

    Full Text Available Laccases, a copper oxidase enzyme, has been employed for bioremediation of anthropogenic pollutants in the recent past. Laccase has a broad range of substrate specificity which offers the prospect for screening in numerable xenobiotics. The present study was aimed to use protein-ligand docking as a tool for prediction of biodegradation of selected pharmaceutical pollutants. A comparative study was also done to determine the binding efficacy of bacterial and fungal laccase for those selected pollutants. The laccase-pollutant docking was carried out using HEX software. The docking scores of bacterial and fungal laccase for predefined pollutants were comparable to ABTS, a substrate for laccase, which suggested that laccase might be able to degrade emerging pharmaceutical pollutants. The docking analysis approach can be useful in prediction of binding competence of pharmaceutical pollutants with laccase for in situ laccase-mediated bioremediation.

  8. Lead resistant bacteria: lead resistance mechanisms, their applications in lead bioremediation and biomonitoring.

    Science.gov (United States)

    Naik, Milind Mohan; Dubey, Santosh Kumar

    2013-12-01

    Lead (Pb) is non-bioessential, persistent and hazardous heavy metal pollutant of environmental concern. Bioremediation has become a potential alternative to the existing technologies for the removal and/or recovery of toxic lead from waste waters before releasing it into natural water bodies for environmental safety. To our best knowledge, this is a first review presenting different mechanisms employed by lead resistant bacteria to resist high levels of lead and their applications in cost effective and eco-friendly ways of lead bioremediation and biomonitoring. Various lead resistant mechanisms employed by lead resistant bacteria includes efflux mechanism, extracellular sequestration, biosorption, precipitation, alteration in cell morphology, enhanced siderophore production and intracellular lead bioaccumulation.

  9. Bioremediation strategies of hydrocarbons and microbial diversity in the Trindade Island shoreline--Brazil.

    Science.gov (United States)

    Rodrigues, Edmo M; Kalks, Karlos H M; Fernandes, Péricles L; Tótola, Marcos R

    2015-12-30

    This study analyzed the microbial diversity colonizing the surface of an oil sample during its contact with water, off the Trindade Island coast and simulated the efficiency of eight different bioremediation strategies for this environment. The diversity analysis was performed using acrylic coupons that served as the support for an oil inclusion at sea. The coupons were sampled over 30 days, and T-RFLP multiplex was employed to access the diversity of fungi, Bacteria and Archaea present on the oil surface. The bioremediation strategies were simulated in a respirometer. The results showed that the bacterial domain was the most dominant in oil colonization and that the richness of the species attached to the oil gradually increases with the exposure time of the coupons. The combination of biostimulation and bioaugmentation with a native population was proven to be an effective strategy for the remediation of oil off the Trindade Island shoreline.

  10. Ecosystem protection by effluent bioremediation: silver nanoparticles impregnation in a textile fabrics process

    Science.gov (United States)

    Durán, Nelson; Marcato, Priscyla D.; Alves, Oswaldo L.; Da Silva, João P. S.; De Souza, Gabriel I. H.; Rodrigues, Flávio A.; Esposito, Elisa

    2010-01-01

    This work studied a bioremediation process of silver nanoparticles with the bacterium Chromobacterium violaceum. These nanoparticles were obtained from several washes of cotton fabrics impregnated with silver nanoparticles produced by the fungus Fusarium oxysporum. The optimized growth of C. violaceum for silver nanoparticles bioremediation was obtained. The effluents of wash process of the cotton fabric were efficiently treated with C. violaceum. This treatment was based on biosorption which was very efficient for the elimination of silver nanoparticles remaining in the wash water. The bacteria after biosorption were morphologically transformed, but the normal morphology after a new culture was completely restored. The process also allowed the recovery of silver material that was leached into the effluent for a reutilization avoiding any effect to the eco-environment.

  11. Potential of bioremediation for buried oil removal in beaches after an oil spill.

    Science.gov (United States)

    Pontes, Joana; Mucha, Ana P; Santos, Hugo; Reis, Izabela; Bordalo, Adriano; Basto, M Clara; Bernabeu, Ana; Almeida, C Marisa R

    2013-11-15

    Bioremediation potential for buried oil removal, an application still lacking thorough research, was assessed in a specifically designed system in which an artificially contaminated oil layer of sand was buried in a sand column subjected to tidal simulation. The efficiency of biostimulation (BS, fertilizer addition) and bioaugmentation (BA, inoculation of pre-stimulated indigenous hydrocarbon-degrading microorganisms plus fertilizer) compared to natural attenuation was tested during a 180-day experimental period. The effect of BA was evident after 60 days (degradation of hydrocarbons reached 80%). BS efficacy was revealed only after 120 days. Microorganisms and nutrients added at the top of the sand column were able to reach the buried oil layer and contributed to faster oil elimination, an important feature for effective bioremediation treatments. Therefore, autochthonous BA with suitable nutritive conditions results in faster oil-biodegradation, appears to be a cost-effective methodology for buried oil remediation and contributes to the recovery of oil-impacted areas.

  12. [Bioremediation of petroleum hydrocarbon-contaminated soils by cold-adapted microorganisms: research advance].

    Science.gov (United States)

    Wang, Shi-jie; Wang, Xiang; Lu, Gui-lan; Wang, Qun-hui; Li, Fa-sheng; Guo, Guan-lin

    2011-04-01

    Cold-adapted microorganisms such as psychrotrophs and psychrophiles widely exist in the soils of sub-Arctic, Arctic, Antarctic, alpine, and high mountains, being the important microbial resources for the biodegradation of petroleum hydrocarbons at low temperature. Using the unique advantage of cold-adapted microorganisms to the bioremediation of petroleum hydrocarbon-contaminated soils in low temperature region has become a research hotspot. This paper summarized the category and cold-adaptation mechanisms of the microorganisms able to degrade petroleum hydrocarbon at low temperature, biodegradation characteristics and mechanisms of different petroleum fractions under the action of cold-adapted microorganisms, bio-stimulation techniques for improving biodegradation efficiency, e. g., inoculating petroleum-degrading microorganisms and adding nutrients or bio-surfactants, and the present status of applying molecular biotechnology in this research field, aimed to provide references to the development of bioremediation techniques for petroleum hydrocarbon-contaminated soils.

  13. Enzymatic hydrolysis and characterization of waste lignocellulosic biomass produced after dye bioremediation under solid state fermentation.

    Science.gov (United States)

    Waghmare, Pankajkumar R; Kadam, Avinash A; Saratale, Ganesh D; Govindwar, Sanjay P

    2014-09-01

    Sugarcane bagasse (SCB) adsorbes 60% Reactive Blue172 (RB172). Providensia staurti EbtSPG able to decolorize SCB adsorbed RB172 up to 99% under solid state fermentation (SSF). The enzymatic saccharification efficiency of waste biomass after bioremediation of RB172 process (ddSCB) has been evaluated. The cellulolyitc crude enzyme produced by Phanerochaete chrysosporium used for enzymatic hydrolysis of native SCB and ddSCB which produces 0.08 and 0.3 g/L of reducing sugars respectively after 48 h of incubation. The production of hexose and pentose sugars during hydrolysis was confirmed by HPTLC. The effect of enzymatic hydrolysis on SCB and ddSCB has been evaluated by FTIR, XRD and SEM analysis. Thus, during dye biodegradation under SSF causes biological pretreatment of SCB which significantly enhanced its enzymatic saccharification. Adsorption of dye on SCB, its bioremediation under SSF produces wastes biomass and which further utilized for enzymatic saccharification for biofuel production.

  14. Biological sand filters: low-cost bioremediation technique for production of clean drinking water.

    Science.gov (United States)

    Lea, Michael

    2014-05-01

    Approximately 1.1 billion people in rural and peri-urban communities of developing countries do not have access to safe drinking water. The mortality from diarrheal-related diseases amounts to ∼2.2 million people each year from the consumption of unsafe water. Most of them are children under 5 years of age--250 deaths an hour from microbiologically contaminated water. There is conclusive evidence that one low-cost household bioremediation intervention, use of biological sand filters, is capable of dramatically improving the microbiological quality of drinking water. This unit will describe this relatively new and proven bioremediation technology's ability to empower at-risk populations to use naturally occurring biological principles and readily available materials as a sustainable way to achieve the health benefits of safe drinking water.

  15. Biodegradation of Alaska North Slope crude oil enhanced by commercial bioremediation agents

    Energy Technology Data Exchange (ETDEWEB)

    Aldrett, S.; Bonner, J.S.; Mills, M.A.; McDonald, T.J.; Autenrieth, R.L. [Texas A and M Univ., College Station, TX (United States). Dept. of Civil Engineering

    1996-09-01

    The biodegradation of crude oil was studied. Tests were conducted in which natural unpolluted seawater was collected and then contaminated with Alaska North Slope crude oil. The oil was weathered by heating it to 521 degrees F to remove the light-end hydrocarbons. A total of 13 different bioremediation agents were tested, each one separately. Three samples per treatment were destructively analysed for petroleum chemistry. The thirteen treatments were analyzed for oil and grease. It was found that microbial degradation of petroleum hydrocarbons was enhanced by the addition of bioremediation agents, but it was not possible to identify the intermediate products responsible for the increase of resolved petroleum hydrocarbons through time. It was suggested that caution be used when interpreting results since the protocols used to test the products were prone to uncontrollable variations. 11 refs., 5 tabs., 6 figs.

  16. Laboratory-scale in situ bioremediation in heterogeneous porous media: Biokinetics-limited scenario

    Science.gov (United States)

    Song, Xin; Hong, Eunyoung; Seagren, Eric A.

    2014-03-01

    Subsurface heterogeneities influence interfacial mass-transfer processes and affect the application of in situ bioremediation by impacting the availability of substrates to the microorganisms. However, for difficult-to-degrade compounds, and/or cases with inhibitory biodegradation conditions, slow biokinetics may also limit the overall bioremediation rate, or be as limiting as mass-transfer processes. In this work, a quantitative framework based on a set of dimensionless coefficients was used to capture the effects of the competing interfacial and biokinetic processes and define the overall rate-limiting process. An integrated numerical modeling and experimental approach was used to evaluate application of the quantitative framework for a scenario in which slow-biokinetics limited the overall bioremediation rate of a polycyclic aromatic hydrocarbon (naphthalene). Numerical modeling was conducted to simulate the groundwater flow and naphthalene transport and verify the system parameters, which were used in the quantitative framework application. The experiments examined the movement and biodegradation of naphthalene in a saturated, heterogeneous intermediate-scale flow cell with two layers of contrasting hydraulic conductivities. These experiments were conducted in two phases: Phase I, simulating an inhibited slow biodegradation; and Phase II, simulating an engineered bioremediation, with system perturbations selected to enhance the slow biodegradation rate. In Phase II, two engineered perturbations to the system were selected to examine their ability to enhance in situ biodegradation. In the first perturbation, nitrogen and phosphorus in excess of the required stoichiometric amounts were spiked into the influent solution to mimic a common remedial action taken in the field. The results showed that this perturbation had a moderate positive impact, consistent with slow biokinetics being the overall rate-limiting process. However, the second perturbation, which was to

  17. Model-based analysis of the role of biological, hydrological and geochemical factors affecting uranium bioremediation.

    Science.gov (United States)

    Zhao, Jiao; Scheibe, Timothy D; Mahadevan, R

    2011-07-01

    Uranium contamination is a serious concern at several sites motivating the development of novel treatment strategies such as the Geobacter-mediated reductive immobilization of uranium. However, this bioremediation strategy has not yet been optimized for the sustained uranium removal. While several reactive-transport models have been developed to represent Geobacter-mediated bioremediation of uranium, these models often lack the detailed quantitative description of the microbial process (e.g., biomass build-up in both groundwater and sediments, electron transport system, etc.) and the interaction between biogeochemical and hydrological process. In this study, a novel multi-scale model was developed by integrating our recent model on electron capacitance of Geobacter (Zhao et al., 2010) with a comprehensive simulator of coupled fluid flow, hydrologic transport, heat transfer, and biogeochemical reactions. This mechanistic reactive-transport model accurately reproduces the experimental data for the bioremediation of uranium with acetate amendment. We subsequently performed global sensitivity analysis with the reactive-transport model in order to identify the main sources of prediction uncertainty caused by synergistic effects of biological, geochemical, and hydrological processes. The proposed approach successfully captured significant contributing factors across time and space, thereby improving the structure and parameterization of the comprehensive reactive-transport model. The global sensitivity analysis also provides a potentially useful tool to evaluate uranium bioremediation strategy. The simulations suggest that under difficult environments (e.g., highly contaminated with U(VI) at a high migration rate of solutes), the efficiency of uranium removal can be improved by adding Geobacter species to the contaminated site (bioaugmentation) in conjunction with the addition of electron donor (biostimulation). The simulations also highlight the interactive effect of

  18. Evaluating the efficacy of bioremediating a diesel-contaminated soil using ecotoxicological and bacterial community indices.

    Science.gov (United States)

    Khudur, Leadin Salah; Shahsavari, Esmaeil; Miranda, Ana F; Morrison, Paul D; Nugegoda, Dayanthi; Ball, Andrew S

    2015-10-01

    Diesel represents a common environmental contaminant as a result of operation, storage, and transportation accidents. The bioremediation of diesel in a contaminated soil is seen as an environmentally safe approach to treat contaminated land. The effectiveness of the remediation process is usually assessed by the degradation of the total petroleum hydrocarbon (TPH) concentration, without considering ecotoxicological effects. The aim of this study was to assess the efficacy of two bioremediation strategies in terms of reduction in TPH concentration together with ecotoxicity indices and changes in the bacterial diversity assessed using PCR-denaturing gradient gel electrophoresis (DGGE). The biostimulation strategy resulted in a 90 % reduction in the TPH concentration versus 78 % reduction from the natural attenuation strategy over 12 weeks incubation in a laboratory mesocosm-containing diesel-contaminated soil. In contrast, the reduction in the ecotoxicity resulting from the natural attenuation treatment using the Microtox and earthworm toxicity assays was more than double the reduction resulting from the biostimulation treatment (45 and 20 % reduction, respectively). The biostimulated treatment involved the addition of nitrogen and phosphorus in order to stimulate the microorganisms by creating an optimal C:N:P molar ratio. An increased concentration of ammonium and phosphate was detected in the biostimulated soil compared with the naturally attenuated samples before and after the remediation process. Furthermore, through PCR-DGGE, significant changes in the bacterial community were observed as a consequence of adding the nutrients together with the diesel (biostimulation), resulting in the formation of distinctly different bacterial communities in the soil subjected to the two strategies used in this study. These findings indicate the suitability of both bioremediation approaches in treating hydrocarbon-contaminated soil, particularly biostimulation. Although

  19. Metagenomic analysis of the bioremediation of diesel-contaminated Canadian high arctic soils.

    Directory of Open Access Journals (Sweden)

    Etienne Yergeau

    Full Text Available As human activity in the Arctic increases, so does the risk of hydrocarbon pollution events. On site bioremediation of contaminated soil is the only feasible clean up solution in these remote areas, but degradation rates vary widely between bioremediation treatments. Most previous studies have focused on the feasibility of on site clean-up and very little attention has been given to the microbial and functional communities involved and their ecology. Here, we ask the question: which microorganisms and functional genes are abundant and active during hydrocarbon degradation at cold temperature? To answer this question, we sequenced the soil metagenome of an ongoing bioremediation project in Alert, Canada through a time course. We also used reverse-transcriptase real-time PCR (RT-qPCR to quantify the expression of several hydrocarbon-degrading genes. Pseudomonas species appeared as the most abundant organisms in Alert soils right after contamination with diesel and excavation (t = 0 and one month after the start of the bioremediation treatment (t = 1m, when degradation rates were at their highest, but decreased after one year (t = 1y, when residual soil hydrocarbons were almost depleted. This trend was also reflected in hydrocarbon degrading genes, which were mainly affiliated with Gammaproteobacteria at t = 0 and t = 1m and with Alphaproteobacteria and Actinobacteria at t = 1y. RT-qPCR assays confirmed that Pseudomonas and Rhodococcus species actively expressed hydrocarbon degradation genes in Arctic biopile soils. Taken together, these results indicated that biopile treatment leads to major shifts in soil microbial communities, favoring aerobic bacteria that can degrade hydrocarbons.

  20. Importance of organic amendment characteristics on bioremediation of PAH-contaminated soil.

    Science.gov (United States)

    Lukić, B; Huguenot, D; Panico, A; Fabbricino, M; van Hullebusch, E D; Esposito, G

    2016-08-01

    This study investigates the importance of the organic matter characteristics of several organic amendments (i.e., buffalo manure, food and kitchen waste, fruit and vegetables waste, and activated sewage sludge) and their influence in the bioremediation of a polycyclic aromatic hydrocarbons (PAH)-contaminated soil. The removal of low molecular weights (LMW) and high molecular weights (HMW) PAHs was monitored in four bioremediation reactors and used as an indicator of the role of organic amendments in contaminant removal. The total initial concentration of LMW PAHs was 234 mg kg(-1) soil (dry weight), while the amount for HMW PAHs was 422 mg kg(-1) soil (dry weight). Monitoring of operational parameters and chemical analysis was performed during 20 weeks. The concentrations of LMW PAH residues in soil were significantly lower in reactors that displayed a mesophilic phase, i.e., 11 and 15 %, compared to reactors that displayed a thermophilic phase, i.e., 29 and 31 %. Residual HMW PAHs were up to five times higher compared to residual LMW PAHs, depending on the reactor. This demonstrated that the amount of added organic matter and macronutrients such as nitrogen and phosphorus, the biochemical organic compound classes (mostly soluble fraction and proteins), and the operational temperature are important factors affecting the overall efficiency of bioremediation. On that basis, this study shows that characterization of biochemical families could contribute to a better understanding of the effects of organic amendments and clarify their different efficiency during a bioremediation process of PAH-contaminated soil.