Download or read book Investigation of Two Microbial Delivery Systems for the in Situ Bioremediation of PAH Contaminated River Sediment written by Don C. Haddox and published by . This book was released on 2000 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of In situ Bioremediation of PAH Contaminated Sediments Using Hollow Fiber Membranes written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Sediment contamination is a global environmental issue and there are no treatment technologies that can be readily applied except dredging, which is very expensive and time consuming. In this thesis, a computer model has been developed and applied to in-situ bioremediation of contaminated sediments. The mathematical model has been applied to experimental data that was obtained previously using a bench-scale system using sediments contaminated with polycyclic aromatic hydrocarbons (PAHs). The use of hollow fiber membranes offers advantages of cost-effectively supplying and controlling the availability of oxygen (air), nutrients or other electron acceptors, such as nitrate and sulfate to the contaminated sediments, without significant loss to the water column. The biokinetic and transport parameters in the mathematical model were fitted to the bench-scale experimental data to achieve a low average error between the experimental and model values. The fitted model was used to calculate the design of the hollow fiber system, such as distance between the fibers. The WASP-6 computer program, developed previously for calculating dissolved oxygen levels in natural water bodies, was used to simulate the impact of contaminated sediments and the effect of using the membrane system to preserve the dissolved oxygen levels. Results of this study have shown that controlled delivery of oxygen from air is a feasible technique to achieve accelerated bioremediation rates of PAH contaminated sediments and improved water quality in rivers and lakes adversely impacted by these contaminated sediments.
Download or read book In Situ Bioremediation of Perchlorate in Groundwater written by Hans F. Stroo and published by Springer. This book was released on 2008-12-02 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the late 1970s and early 1980s, our nation began to grapple with the legacy of past disposal practices for toxic chemicals. With the passage in 1980 of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), commonly known as Superfund, it became the law of the land to remediate these sites. The U. S. Department of Defense (DoD), the nation’s largest industrial organization, also recognized that it too had a legacy of contaminated sites. Historic operations at Army, Navy, Air Force, and Marine Corps facilities, ranges, manufacturing sites, shipyards, and depots had resulted in widespread contamination of soil, groundwater, and sediment. While Superfund began in 1980 to focus on remediation of heavily contaminated sites largely abandoned or neglected by the private sector, the DoD had already initiated its Installation Restoration Program in the mid 1970s. In 1984, the DoD began the Defense Environmental Restoration Program (DERP) for contaminated site assessment and remediation. Two years later, the U. S. Congress codified the DERP and directed the Secretary of Defense to carry out a concurrent program of research, development, and demonstration of innovative remediation technologies. As chronicled in the 1994 National Research Council report, “Ranking Hazardous-Waste Sites for Remedial Action”, our early estimates on the cost and suitability of existing technologies for cleaning up contaminated sites were wildly optimistic. Original estimates, in 1980, projected an average Superfund cleanup cost of a mere $3.
Download or read book Investigation of Transport and Degradation Processes of Polycyclic Aromatic Hydrocarbons in Biofilm written by Elena Christine Pfarr and published by . This book was released on 2004 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Pleurotus Ostreatus on Bioremediation of Polycyclic Aromatic Hydrocarbon Contaminated River Sediment written by Matthew D. Gacura and published by . This book was released on 2009 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this study was to optimize bioremediation of Mahoning River sediment historically contaminated with polycyclic aromatic hydrocarbons (PAHs) using white rot fungi. Pleurotus ostreatus grown on grain (10% v/v) was added to contaminated sediment amended with sawdust (80% v/v), with and without fungal specific nutritional nitrogen (to enhance fungal growth), and with cyclodextrin (to increase PAH availability). Sediment mixtures were incubated in the dark at 25°C for 6 weeks. Sawdust made the sediment more porous, allowed better colonization by fungi, and did not greatly increase volume. Fungal biomass, determined using fluorescent microscopy, indicated initial fungal colonization but then fungal growth was inhibited, likely by toxic metals or high moisture content in the sediment. Growth of unidentified fungi was observed, especially in treatments amended with nitrogen. Total PAH concentrations (in the order of 100 ppm), analyzed using a gas chromatograph mass spectrometer (GCMS), and significantly decreased ~ 50-60% in all treatments, including sediment only controls within the first two weeks. Thus, aerobic degradation by native bacteria and volatilization were likely responsible for most of the observed decreases in PAH concentrations. High heterogeneity of PAHs in this historically contaminated sediment led to high variance between replicates. There was a slight decrease in 5 ring PAHs associated with sediment inoculated with P. ostreatus and also a slight decrease in total PAH concentrations associated with sediment amended with sawdust and cyclodextrin (with or without P. ostreatus). Increased nitrogen did not enhance PAH degradation. Sediment inoculated with P. ostreatus after two weeks, rather than initially, showed better fungal growth and colonization, but PAH data was not yet available. These data indicate there is great potential for bioremediation of PAH contaminated sediment conditions by stimulating indigenous bacteria under aerobic conditions followed by the addition of white rot fungi. However, further testing and optimization is still required.
Download or read book PAH Impact on the Sediment Bacterial Community written by SF. Pikett and published by . This book was released on 1995 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: The potential for bioremediating polycyclic aromatic hydrocarbons (PAHs), the major constituents of creosote, will depend on the response of the sediment bacterial community. The microbial community in sediments from a creosote-polluted freshwater lake was studied. The aim of this study was to assess the impact of PAH contamination on the sediment bacterial community. Sediment samples were taken at selected sites around the lake and upstream at an unpolluted site. Samples were analyzed for selected PAH concentrations. The numbers of aerobic heterotrophic bacteria isolated after growth on peptone yeast extract agar, peptone yeast extract with added creosote agar, and a minimal media with added creosote agar were determined for each site. The response of different bacterial physiological types to PAH contamination in sediment ecosystems was assessed through the use of a gel-stabilized model system. It was apparent that the PAH contamination had a marked effect on the bacterial community of these freshwater sediments. Such effects may influence the cycling of nutrients within sediments, e.g., the nitrogen and sulfur cycle, and the potential for in situ bioremediation.
Download or read book Solid Peroxide Stimulated Phenanthrene Removal from Contaminated River Sediment written by Katherine Stuart Schaffnit and published by . This book was released on 2009 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Model Systems for in Situ Bioremediation written by Belinda May Hewitt and published by . This book was released on 2011 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bioremediation has emerged as a promising treatment approach for restoring contaminated environments, where microorganisms degrade organic pollutants into non-harmful end products. Polycyclic Aromatic Hydrocarbons (PAHs) are a hazardous class of pollutants which have accumulated in soils as a by-product of fossil fuel use. A growing field of research is investigating ways to enhance bioremediation as strategy for removing PAHs from soil environments, where the principal limiting factors for biological degradation activity are pollutant/microbe interaction and the ability of an organism to catabolise a pollutant. A number of engineered treatment approaches aim to address these limits by improving PAH bioavailability and stimulating microbial degradation activity; such as the bioaugmentation of soils with live bacteria degrader cultures and the application of surface acting agents in liquid and microbubble form. However, progress in this field has been limited, as bioremediation processes have not been well characterised at a cellular or molecular scale. Recent advances in microbiology and genetics have allowed for the creation of fluorescent biological sensor organisms which can be engineered to produce a signal response in association with a specific cellular activity. This research presents proof of concept for application of a novel fibre optic 'Optrode' fluorescence detection system to monitor biological activity in model soil column environments. A new strain of naphthalene degrading bacteria was engineered for use in this research, from which fluorescent biosensor strains were developed using recombinant gene technology. Biosensors were detectable at levels commonly reported at bioremediation treatment sites, and were identified in model bench-scale soil columns using the Optrode system. Recent studies suggest that surfactant microbubble foams may enhance bacterial transport and pollutant availability in bioremediation scenarios, however there has been no investigation in regards to the behaviour of these substances in the soil environments. Bench scale-soil columns were developed in order to investigate and compare the fate of biosurfactant solutions, foams, biosensor bacteria and naphthalene in model subsurface environments using advection-dispersion models. Rhamnolipid biosurfactant solution was found to significantly improve hydraulic conductivity and bacterial advection in packed porous media. Naphthalene was highly immobile in surfactant solution, and model results suggest that a major aspect of naphthalene adsorption loss was due to adhesion with micellar structures in the soil column. Advection-dispersion models were used to describe the distribution of Rhamnolipid microbubble foams in soil columns, which constitutes a crucial first step in characterising the behaviour and distribution of biosurfactant microbubble foams in subsurface environments. Breakthrough models suggest that the liquid and gaseous phases of microbubble foams have different fates in the soil column, and their distribution may be better described using a two phase flow system. Best fits for advection dispersion models suggest that while solute distribution in foam is restricted to the liquid phase, bacteria interact with both the liquid and gaseous phases, so their transport through soil column environments may be enhanced even when liquid drainage occurs. This research demonstrates that a combined approach of bench-scale soil column modelling and in situ monitoring of biological activity is able to characterise real-time biodegradation processes at a fine scale. The development of a comprehensive system for investigating and optimising bioremediation is an important aspect of enhancing the progression of treatment strategies into successful field application.
Download or read book Bioremediation of Recalcitrant Compounds written by Jeffrey Talley and published by CRC Press. This book was released on 2016-04-19 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: This authoritative text addresses the latest in bioremediation technologies for three difficult-to-treat contaminant groups: chlorinated solvents, PCBs, and PAHs - one of the most complex and expensive areas of applied remediation engineering. Bioremediation of Recalcitrant Compounds assesses innovative R&D projects developed for each contam
Download or read book Characterization and Bioremediation Viability of Polycyclic Aromatic Hydrocarbon Contamination in the Banks of the Mahoning River written by Steven A. Buffone and published by . This book was released on 2015 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discharge of wastes into the lower Mahoning River in Northeastern Ohio since the 19th century has resulted in the accumulation of toxic hydrocarbons, including PAHs, in the river channel and river bank sediments. This study characterizes the polluted bank sediments and evaluates the feasibility of cleanup using in situ bioremediation. Characterization was undertaken in order to study the feasibility of in situ bioremediation. This was accomplished through the collection of 208 samples from 37 soil borings from both banks at five locations along the river. Samples were then analyzed by grain-size analysis and hydraulic conductivities were estimated using the Hazen method. Soil borings also revealed the following: depth to groundwater, depth to bedrock, the upper and lower limits of hydrocarbon contamination, and the thickness of the hydrocarbon contamination in the river banks. Slug tests were performed at four locations to evaluate hydraulic conductivity in very fine-grained sediments, which could not properly be evaluated by the Hazen method. Flow between the groundwater in the bank and the river channel was monitored at four locations for a period of up to one year. Monitoring confirmed the active exchange of flow between the river channel and the banks. This exchange is capable of recontaminating the river's channel by transporting the dissolved contaminants from the bank, via groundwater if the banks are not remediated. PAHs were analyzed in soil samples taken from five locations which verified PAH impact at all four locations. Based on groundwater flow directions, sediment makeup, hydraulic conductivity distribution, thickness of contamination, and PAH availability, this study suggests first, the probability of leaching from impacted bank sediment to groundwater and second, based on the values of hydraulic conductivity that in situ bioremediation is feasible.
Download or read book Biodegradation and Bioavailability Studies on Aged Pah contaminated Sediment written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The degradation of PAHs by bacteria indigenous to chronically field-contaminated sediment was investigated, where the sediment served as both the inoculum and the medium containing PAHs. Microbial composition and dynamics under representative conditions were characterized by Denaturing Gradient Gel Electrophoresis (DGGE). Due to the high content of reduced sulfur compounds in the sediment, rapid oxygen depletion and severe acidification resulted from intensive activities of sulfur-oxidizing bacteria affiliated with the genus Thiovulum . Proper use of crushed limestone and an oxygen delivery protocol successfully avoided acidification and satisfied the oxygen demand of the system. With sufficient oxygen, substantial biodegradation of 2-, 3-, 4-, and 5-ring PAHs was achieved, while no appreciable degradation of 6-ring compounds was observed. Phylogenetic analysis of the microbial communities in various aerobic slurries with different additives revealed the selection of species associated with genera Cytophaga and Sphingomonas .Only phenanthrene showed a significant degradation coupled to sulfate reduction. Two dominant species grouped with the genus Bacteroides were probably involved in the degradation. They related to clones involved in the degradation of aromatic hydrocarbons with sulfate as the electron acceptor. Under denitrifying conditions, no appreciable PAH degradation was observed, while the reduction of nitrate to nitrogen occurred stoichiometrically with the production of sulfate. This was due to the absolute dominance of an autotrophic, Thiomicrospira denitrificans -like denitrifier. The addition of ethanol or acetate, as applied, was unable to encourage the dominance of heterotrophic denitrifiers, which was necessary for PAH biodegradation. An XAD-2 assisted desorption assay was developed for assessing the bioavailability of PAHs in the sediment. Its promise was demonstrated by the strong agreement between final residual levels of all the 2-, 3-, and 4-ring PAHs after biodegradation and desorption. This suggests that bioavailability was the factor limiting the biodegradation of these PAHs, and explains why addition of nutrients, co-substrates, or surfactants, as practiced, did not improve the extent of degradation in aerobic systems, although different dominant species resulted in response to these amendments. Mild extractions using certain isopropanol- or ethanol-water solutions could also approximate the bioavailability of PAHs, which, however, require intensive studies of extraction parameters.
Download or read book Bioremediation of Chlorinated and Polycyclic Aromatic Hydrocarbon Compounds written by Battelle Memorial In and published by CRC Press. This book was released on 1994-02-28 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt: This timely reference presents the state of the art of the emerging and rapidly changing field of bioremediation of chlorinated solvents, PCBs, and other chlorinated compounds, as well as PAHs, both in situ and on site. This landmark publication reports significant advances in bioremediation, with an emphasis on practical applications and state-of-the-art developments. Laboratory and field-oriented reviews are presented with the objective of tying treatability studies and recent laboratory developments to field applications. No other reference source gives you access to the most current techniques and methods for the bioremediation of chlorinated and polycyclic aromatic hydrocarbon compounds. This book represents the work of leading experts in the fields of in situ and on-site bioremediation from North America, Europe, and Asia. The chapters include current field applications and laboratory studies undertaken, in some cases, in countries with regulatory standards more stringent than those of the United States.
Download or read book In Situ Bioreclamation written by Robert E. Hinchee and published by Butterworth-Heinemann. This book was released on 1991 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt: See following entry.
Download or read book Bioremediation of Petroleum Contaminated Sites written by RiseR-RobeRts and published by CRC Press. This book was released on 1992-07-15 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bioremediation of Petroleum Contaminated Sites provides important background information on the major aspects of technologies and related research dealing with the use of biodegradation for treating environmental contamination by toxic organic substances. The book can be used as a broad reference base for developing programs for in situ biorestoration of fuel contaminated soil and groundwater. A detailed appendix includes supplementary technical information for readers needing in-depth information. Bioremediation of Petroleum Contaminated Sites is an excellent reference for managers, consultants, regulators, hazardous waste professionals, contractors, students, and environmental researchers.
Download or read book Investigation of Mechanisms that Affect the Biokinetics for in Situ Bioremediation of PAH Contaminated Soil written by Kelly Ann Smith and published by . This book was released on 1998 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biostabilization of Polycyclic Aromatic Hydrocarbons PAHs Under Denitrification Conditions in Sediments written by and published by . This book was released on 2000 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Carnegie Mellon University and Stanford University investigated the anaerobic biodegradation of polycyclic aromatic hydrocarbons (PAHs) in contaminated sediments under bioslurry denitrifying conditions. Samples from sediment bioslurry tests and toxicity bioassays were used to assess PAH bioavailability as inferred from subparticle-scale measurement of PAH locations on sediment particles and association with sorbent organic matter. The research employed new microscale, analytic measurement techniques: microprobe, two-step laser desorption/laser ionization mass spectrometry; infrared microspectroscopy; wavelength dispersive X-ray analysis; and thermal desorption mass spectrometry. These techniques provide information on subparticle-scale PAH distributions in sediment. CMU researchers have reviewed relevant studies, cultivated Pseudomonas putida KBM1, a strain of microorganisms capable of degrading PAHs under denitrifying conditions, and conducted anaerobic and aerobic PAH degradation studies. R G. Luthy has leveraged the experimental studies with a major Gas Research Institute initiative on environmentally acceptable endpoints. CMU and Stanford have examined PAH distribution on dredged Milwaukee harbor sediment obtained from the Jones Island confined disposal facility. Subparticle-scale analyses have shown that PAH sorption involves near-surface sorption processes, rather than particle-scale diffusion phenomena, and that coal-like particles contain many times more PM's than silica particles. Results from anaerobic and aerobic biodegradation experiments conducted with two PAH contaminated sediments are presented in this final report.
Download or read book A Study of Pollutant and Bacterial Transport Through Porous Media for In situ Bioremediation Applications written by Aditya Veer and published by . This book was released on 2013 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polycyclic Aromatic Hydrocarbons are considered to be priority pollutants by USEPA and other agencies. Their accumulation in groundwater and subsurface environment has necessitated development of treatment methods to control their bioaccumulation in the living environment. Ex-situ techniques have been tried for decades to treat the pollutants, but they are cost-prohibitive and tedious. In-situ techniques offer potential advantages to this cause. The in-situ techniques designed currently lack a comprehensive understanding of transport processes occurring in subsurface soil region. Understanding the same will allow us to engineer an effective design to treat hydrophobic organic contaminants. Their special properties need modelling studies to correlate their behaviour with conservative solutes. This will enable us to optimise the infiltration rate and remediation volume and geometry for specific regions. Naturally occurring and genetically modified bacteria are capable of degrading highly recalcitrant compounds. But the hydrophobic nature of the contaminants makes it necessary to use special delivery mechanisms to facilitate the interaction between the two. Surfactant and microbubble suspensions are favoured due to the improved flow properties observed. This study attempts to explore and identify key components that determine the transport behaviour of contaminants and bacteria in porous media, in order to increase our understanding of the underlying processes. Foam transport forms an important aspect in this study. Foam is a favourable medium for transport as it provides simultaneous bioaugmentation and biostimulation. The transport parameters need to be characterised to optimise our treatment systems. This area has been identified as the knowledge gap which we try to close in. This study also introduces novel in-situ measurement technique for monitoring bacterial population without the need for invasive sampling techniques. The study is still in its initial stages and, hence, considerable scope lays ahead to modify and improve on the current design of experimental setup and remediation strategies. However, this study provides a proof-of-concept for the operation of these innovative techniques. Bacterial transport is not studied in extensive detail due to certain limitations encountered over the course of the project.
