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ENHANCED PRACTICAL PHOTOSYNTHETIC CO2 MITIGATION

Description: This quarterly report documents significant achievements in the Enhanced Practical Photosynthetic CO{sub 2} Mitigation project during the period from 1/2/2003 through 4/01/2003. As indicated in the list of accomplishments below we are progressing with long-term model scale bioreactor tests and are completing final preparations for pilot scale bioreactor testing. Specific results and accomplishments for the first quarter of 2003 are included.
Date: April 15, 2003
Creator: Kremer, Dr. Gregory; Bayless, Dr. David J.; Vis, Dr. Morgan; Prudich, Dr. Michael; Cooksey, Dr. Keith & Muhs, Dr. Jeff
Partner: UNT Libraries Government Documents Department

Bioprocessing of crude oils and desulfurization using electro-spray reactors

Description: Biological removal of organic sulfur from petroleum feedstocks offers an attractive alternative to conventional thermochemical treatment due to the mild operating conditions afforded by the biocatalyst. Electro-spray bioreactors were investigated for use in desulfurization due to their reported operational cost savings relative to mechanically agitated reactors and their capability of forming emulsions < 5 {micro}m. Here, the rates dibenzothiophene (DBT) oxidation to 2-hydroxybiphenyl (2-HBP) in hexadecane, by Rhodococcus sp. IGTS8 are compared in the two reactor systems. Desulfurization rates ranged from 1.0 and 5.0 mg 2-HBP/(dry g cells-h), independent of the reactor employed. The batch stirred reactor was capable of forming a very fine emulsion in the presence of the biocatalyst IGTS8, similar to that formed in the electro-spray reactors, presumably due to the fact that the biocatalyst produces its own surfactant. While electro-spray reactors did not prove to be advantageous for the IGTS8 desulfurization system, it may prove advantageous for systems which do not produce surface-active bioagents in addition to being mass transport limited.
Date: July 1, 1998
Creator: Kaufman, E. N. & Borole, A. P.
Partner: UNT Libraries Government Documents Department

Treatment of Produced Water Using a Surfactant Modified Zeolite/Vapor Phase Bioreactor System

Description: Co-produced water from the oil and gas industry accounts for a significant waste stream in the United States. Produced waters typically contain a high total dissolved solids content, dissolved organic constituents such as benzene and toluene, an oil and grease component as well as chemicals added during the oil-production process. It has been estimated that a total of 14 billion barrels of produced water were generated in 2002 from onshore operations (Veil, 2004). Although much of this produced water is disposed via reinjection, environmental and cost considerations can make surface discharge of this water a more practical means of disposal. In addition, reinjection is not always a feasible option because of geographic, economic, or regulatory considerations. In these situations, it may be desirable, and often necessary from a regulatory viewpoint, to treat produced water before discharge. It may also be feasible to treat waters that slightly exceed regulatory limits for re-use in arid or drought-prone areas, rather than losing them to reinjection. A previous project conducted under DOE Contract DE-AC26-99BC15221 demonstrated that surfactant modified zeolite (SMZ) represents a potential treatment technology for produced water containing BTEX. Laboratory and field experiments suggest that: (1) sorption of benzene, toluene, ethylbenzene and xylenes (BTEX) to SMZ follows linear isotherms in which sorption increases with increasing solute hydrophobicity; (2) the presence of high salt concentrations substantially increases the capacity of the SMZ for BTEX; (3) competitive sorption among the BTEX compounds is negligible; and, (4) complete recovery of the SMZ sorption capacity for BTEX can be achieved by air sparging the SMZ. This report summarizes research for a follow on project to optimize the regeneration process for multiple sorption/regeneration cycles, and to develop and incorporate a vapor phase bioreactor (VPB) system for treatment of the off-gas generated during air sparging. To this end, we ...
Date: January 31, 2006
Creator: Katz, Lynn E.; Kinney, Kerry A.; Bowman, Robert S.; Sullivan, Enid J.; Kwon, Soondong; Darby, Elaine B. et al.
Partner: UNT Libraries Government Documents Department

Treatment of Produced Waters Using a Surfactant Modified Zeolite/Vapor Phase Bioreactor System

Description: This report summarizes work performed on this project from April 2004 through September 2004. Our previous work demonstrated that a polyurethane foam biofilter could successfully biodegrade the BTEX contaminants found in the SMZ regeneration waste gas stream. However, establishing the biomass on the polyurethane foam packing was relatively time consuming and daily recirculation of a concentrated nutrient solution was required for efficient operation of the foam biofilter. To simplify the start up and operating requirements of the biofilter system, a simple, compost-based biofilter was investigated for its ability to treat the BTEX contaminants generated during the SMZ regeneration process. The investigation of the compost biofilter was divided into three experimental phases that spanned 180 days of biofilter operation. During Phase 1, the biofilter was continuously supplied a BTEX-contaminated waste gas stream. During Phase 2, a series of periodic shutdown tests were conducted to assess how the biofilter responded when the BTEX feed was discontinued for periods ranging from 1 day to 2.8 days. The Phase 3 experiments focused on determining how the biofilter would handle periodic spikes in inlet BTEX concentration as would be expected when it is coupled with an SMZ column. Results from the continuous feed (Phase 1) experiments demonstrated that the compost biofilter could maintain BTEX removals of greater than 98% within two weeks of startup. Results of the shutdown experiments indicated that benzene removal was the most sensitive to interruptions in the BTEX feed. Nevertheless, the BTEX removal efficiency exceeded 95% within 6 hours of reestablishing the BTEX feed to the biofilter. When the biofilter was subjected to periodic spikes in BTEX concentration (Phase 3), it was found that the total BTEX removal efficiency stabilized at approximately 75% despite the fact that the biofilter was only fed BTEX contaminants 8 hours per day. Finally, the effects ...
Date: September 11, 2004
Creator: Katz, Lynn E.; Kinney, Kerry A.; Bowman, R. S. & Sullivan, E. J.
Partner: UNT Libraries Government Documents Department

ENHANCED PRACTICAL PHOTOSYNTHETIC CO2 MITIGATION

Description: This quarterly report documents significant achievements in the Enhanced Practical Photosynthetic CO{sub 2} Mitigation project during the period from 1/03/2001 through 4/02/2001. Many of the activities and accomplishments are continuations of work initiated and reported in last quarter's status report. Major activities and accomplishments for this quarter include: Three sites in Yellowstone National Park have been identified that may contain suitable organisms for use in a bioreactor; Full-scale culturing of one thermophilic organism from Yellowstone has progressed to the point that there is a sufficient quantity to test this organism in the model-scale bioreactor; The effects of the additive monoethanolamine on the growth of one thermophilic organism from Yellowstone has been tested; Testing of growth surface adhesion and properties is continuing; Construction of a larger model-scale bioreactor to improve and expand testing capabilities is completed and the facility is undergoing proof tests; Model-scale bioreactor tests examining the effects of CO{sub 2} concentration levels and lighting levels on organism growth rates are continuing; Alternative fiber optic based deep-penetration light delivery systems for use in the pilot-scale bioreactor have been designed, constructed and tested; An existing slug flow reactor system has been modified for use in this project, and a proof-of-concept test plan has been developed for the slug flow reactor; Research and testing of water-jet harvesting techniques is continuing, and a harvesting system has been designed for use in the model-scale bioreactor; and The investigation of comparative digital image analysis as a means for determining the ''density'' of algae on a growth surface is continuing Plans for next quarter's work and an update on the project's web page are included in the conclusions.
Date: April 16, 2001
Creator: Bayless, Dr. David J.; Vis, Dr. Morgan; Kremer, Dr. Gregory; Prudich, Dr. Michael; Cooksey, Dr. Keith & Muhs, Dr. Jeff
Partner: UNT Libraries Government Documents Department

Ethanol production from dry-mill corn starch in a fluidized-bed bioreactor

Description: The development of a high-rate process for the production of fuel ethanol from dry-mill corn starch using fluidized-bed bioreactor (FBR) technology is discussed. Experiments were conducted in a laboratory scale FBR using immobilized biocatalysts. Two ethanol production process designs were considered in this study. In the first design, simultaneous saccharification and fermentation was performed at 35 C using {kappa}-carageenan beads (1.5 mm to 1.5 mm in diameter) of co-immobilized glucoamylase and Zymomonas mobilis. For dextrin feed concentration of 100 g/L, the single-pass conversion ranged from 54% to 89%. Ethanol concentrations of 23 to 36 g/L were obtained at volumetric productivities of 9 to 15 g/L-h. No accumulation of glucose was observed, indicating that saccharification was the rate-limiting step. In the second design, saccharification and fermentation were carried out sequentially. In the first stage, solutions of 150 to 160 g/L dextrins were pumped through an immobilized glucoamylase packed column maintained at 55 C. Greater than 95% conversion was obtained at a residence time of 1 h, giving a product of 165 to 170 g glucose/L. In the second stage, these glucose solutions were fed to the FBR containing Z. mobilis immobilized in {kappa}-carageenan beads. At a residence time of 2 h, 94% conversion and ethanol concentration of 70 g/L was achieved, giving an overall productivity of 23 g/L-h.
Date: August 1, 1998
Creator: Krishnan, M. S.; Nghiem, N. P. & Davison, B. H.
Partner: UNT Libraries Government Documents Department

Issues involved with non-characterized control of methanotrophic bacteria

Description: Methane-utilizing bacteria, methanotrophs, have application as biocatalysts in the commodity chemical production, waste treatment and environmental remediation industries. Methanotrophs have the ability to oxidize many chemical compounds into more desired products, such as the production of propylene oxide. Methanotrophs can also degrade toxic compounds such as trichloroethylene. However, there are many physical, chemical and biological problems associated with the continuous oxidation of chemicals. These include, low mass transfer of methane, oxygen and propylene; toxicity of substrates and degradation products, and competition between the growth substrate, i.e., methane and chemical feed stock, e.g., propylene for the biocatalyst. To supervise methanotrophic bioprocesses, an intelligent control system must accommodate any biological limitations, e.g., toxicity, and mitigate the impact of the physical and chemical limitations, e.g., mass transfer of methane and the solubility of propylene. The intelligent control system must have the capability to assess the current conditions and metabolic state of the bacteria; recognize and diagnose instrument faults; and select and maintain sets of parameters that will result in high production and growth.
Date: May 11, 1998
Creator: Stoner, D.L.; Tolle, C.R.; Noah, K.S.; Davis, D.A.; Miller, K.S. & Fife, D.J.
Partner: UNT Libraries Government Documents Department

Removal of chlorinated and non-chlorinated alkanes in a trickle-bed biofilter

Description: Increasing restrictions in emissions from a variety of industrial settings demand low cost removal of dilute contaminants in air. Many of these contaminants such as volatile organic components (VOCs) and sulfur compounds are biodegradable and can be removed from air streams via biofiltration. The simplest form of biofiltration consists of compost-based systems. More advanced systems designed for unique contaminants are biofilters with bioactive structured packing operating in trickle-bed mode. These advanced systems rely on a microbial consortium capable of degrading the contaminants of concern and the consortium usually is isolated or enriched from a more complex microbial mixture. This paper describes the use of a trickle-bed reactor seeded with a microbial consortium enriched from a methanotrophic culture. The microbial consortium has been found to degrade chlorinated alkanes as the sole carbon source. Degradation rates of alkane mixtures are presented for the trickle-bed as well as results from batch cultures experiments designed to study degradation of various chlorinated and non-chlorinated VOCs.
Date: January 1, 1998
Creator: Klasson, K.T.; Davison, B.H.; Barton, J.W. & Jacobs, J.E.
Partner: UNT Libraries Government Documents Department

Development of biological coal gasification (MicGAS process); 14th Quarterly report

Description: Reported here is the progress on the Development of Biological Coal Gasification for DOE contract No. DE-AC21-90MC27226 MOD A006. Task 1, NEPA Compliance and Updated Test Plan has been completed. Progress toward Task 2, Enhanced Methane Production, is reported in the areas of bacterial strain improvement, addition of co-substrates, and low cost nutrient amendment. Conclusions reached as a result of this work are presented. Plans for future work are briefly outlined.
Date: January 28, 1993
Partner: UNT Libraries Government Documents Department

Enhanced Practical Photosynthetic CO2 Mitigation

Description: This report highlights significant achievements in the Enhanced Practical Photosynthetic CO{sub 2} Mitigation Project for the period ending 09/30/2004. The primary effort of this quarter was focused on mass transfer of carbon dioxide into the water film to study the potential effects on the photosynthetic organisms that depend on the carbon. Testing of the carbon dioxide scrubbing capability (mass transfer capability) of flowing water film appears to be relatively high and largely unaffected by transport of the gas through the bioreactor. The implications are that the transfer of carbon dioxide into the film is nearly at maximum and that it is sufficient to sustain photosynthesis at whatever rate the organisms can sustain. This finding is key to assuming that the process is an energy (photon) limited reaction and not a nutrient limited reaction.
Date: October 13, 2004
Creator: Kremer, Gregory; Bayless, David J.; Vis, Morgan; Prudich, Michael; Cooksey, Keith & Muhs, Jeff
Partner: UNT Libraries Government Documents Department

Physiomics Array: A Platform for Genome Research and Cultivation of Difficult-to-Cultivate Microorganisms Final Technical Report

Description: A scalable array technology for parametric control of high-throughput cell cultivations is demonstrated. The technology makes use of commercial printed circuit board (PCB) technology, integrated circuit sensors, and an electrochemical gas generation system. We present results for an array of eight 250 μl microbioreactors. Each bioreactor contains an independently addressable suite that provides closed-loop temperature control, generates feed gas electrochemically, and continuously monitors optical density. The PCB technology allows for the assembly of additional off-the-shelf components into the microbioreactor array; we demonstrate the use of a commercial ISFET chip to continuously monitor culture pH. The electrochemical dosing system provides a powerful paradigm for reproducible gas delivery to high-density arrays of microreactors. We have scaled the technology to a standard 96-well format and have constructed a system that could be easily assembled.
Date: July 10, 2006
Creator: Keasling, Jay D.
Partner: UNT Libraries Government Documents Department

Treatment of Produced Waters Using a Surfactant Modified Zeolite/Vapor Phase Bioreactor System

Description: This report summarizes work of this project from October 2003 through March 2004. The major focus of the research was to further investigate BTEX removal from produced water, to quantify metal ion removal from produced water, and to evaluate a lab-scale vapor phase bioreactor (VPB) for BTEX destruction in off-gases produced during SMZ regeneration. Batch equilibrium sorption studies were conducted to evaluate the effect of semi-volatile organic compounds commonly found in produced water on the sorption of benzene, toluene, ethylbenzene, and xylene (BTEX) onto surfactant-modified zeolite (SMZ) and to examine selected metal ion sorption onto SMZ. The sorption of polar semi-volatile organic compounds and metals commonly found in produced water onto SMZ was also investigated. Batch experiments were performed in a synthetic saline solution that mimicked water from a produced water collection facility in Wyoming. Results indicated that increasing concentrations of semi-volatile organic compounds increased BTEX sorption. The sorption of phenol compounds could be described by linear isotherms, but the linear partitioning coefficients decreased with increasing pH, especially above the pKa's of the compounds. Linear correlations relating partitioning coefficients of phenol compounds with their respective solubilities and octanol-water partitioning coefficients were developed for data collected at pH 7.2. The sorption of chromate, selenate, and barium in synthetic produced water were also described by Langmuir isotherms. Experiments conducted with a lab-scale vapor phase bioreactor (VPB) packed with foam indicated that this system could achieve high BTEX removal efficiencies once the nutrient delivery system was optimized. The xylene isomers and benzene were found to require the greatest biofilter bed depth for removal. This result suggested that these VOCs would ultimately control the size of the biofilter required for the produced water application. The biofilter recovered rapidly from shutdowns showing that the system was resilient to discontinuous feed conditions therefore provided flexibility on ...
Date: March 11, 2004
Creator: Katz, Lynn E.; Kinney, Kerry A.; Bowman, R. S. & Sullivan, E. J.
Partner: UNT Libraries Government Documents Department

Developments in Geothermal Waste Treatment Biotechnology

Description: Extensive laboratory studies have indicated that the application of biochemical processes in the development of biotechnology suitable for conversion of geothermal wastes from hazardous to non-hazardous materials is technically and economically feasible. These studies have also shown that such biotechnology may require bioreactors capable of handling different amounts and types of residual sludges. Particular attention has to be paid to the duration of treatment, efficiency of cycling, and maintenance of biomass. Laboratory studies addressing these parameters are described.
Date: March 21, 1989
Creator: Premuzic, Eugene T. & Lin, Mow S.
Partner: UNT Libraries Government Documents Department

Industrial innovations for tomorrow: Advances in industrial energy-efficiency technologies. New bioreactor can produce high-value chemicals from food processing wastes

Description: Two large-scale ICRS pilot plants are being operated at Midwestern dairies. The Purdue research has focused on using the ICRS to produce ethanol from cheese whey. In this application, the cells of the ICRS are lactose-utilizing yeasts absorbed to a fibrous absorbent packing matrix that converts lactose to ethanol and carbon dioxide.
Date: November 1, 1993
Partner: UNT Libraries Government Documents Department

Treatment of Produced Waters Using a Surfactant Modified Zeolite/Vapor Phase Bioreactor System

Description: This report summarizes work performed on this project from April 2005 through September 2005. In previous work, a series of laboratory scale experiments were conducted to determine the feasibility of using a SMZ system coupled with a VPB to remove and ultimately destroy the organic pollutants found in produced water. Based on the laboratory scale data, a field test of the process was conducted at the McGrath Salt Water Disposal facility in July and August of 2005. The system performed well over repeated feed and regeneration cycles demonstrating the viability of the process for long term operation. Of the BTEX components present in the produced water, benzene had the lowest adsorption affinity for the SMZ and thus controlled the sorption cycle length. Regeneration of the SMZ using air sparging was found to be sufficient in the field to maintain the SMZ adsorption capacity and to allow continuous operation of the system. As expected, the BTEX concentrations in the regeneration off gas stream were initially very high in a given regeneration cycle. However, a granular activated carbon buffering column placed upstream of the VPB reduced the peak BTEX concentrations to acceptable levels for the VPB. In this way, the VPB was able to maintain stable performance over the entire SMZ regeneration period despite the intermittent nature of the feed.
Date: September 11, 2005
Creator: Kwon, Soondong; Darby, Elaine B.; Chen, Li-Jung; Katz, Lynn E.; Kinney, Kerry A.; Bowman, R. S. et al.
Partner: UNT Libraries Government Documents Department

Treatment of Produced Waters Using a Surfactant Modified Zeolite/Vapor Phase Bioreactor System

Description: This report summarizes work performed on this project from October 2004 through March 2005. In previous work, a surfactant modified zeolite (SMZ) was shown to be an effective system for removing BTEX contaminants from produced water. Additional work on this project demonstrated that a compost-based biofilter could biodegrade the BTEX contaminants found in the SMZ regeneration waste gas stream. However, it was also determined that the BTEX concentrations in the waste gas stream varied significantly during the regeneration period and the initial BTEX concentrations were too high for the biofilter to handle effectively. A series of experiments were conducted to determine the feasibility of using a passive adsorption column placed upstream of the biofilter to attenuate the peak gas-phase VOC concentrations delivered to the biofilter during the SMZ regeneration process. In preparation for the field test of the SMZ/VPB treatment system in New Mexico, a pilot-scale SMZ system was also designed and constructed during this reporting period. Finally, a cost and feasibility analysis was also completed. To investigate the merits of the passive buffering system during SMZ regeneration, two adsorbents, SMZ and granular activated carbon (GAC) were investigated in flow-through laboratory-scale columns to determine their capacity to handle steady and unsteady VOC feed conditions. When subjected to a toluene-contaminated air stream, the column containing SMZ reduced the peak inlet 1000 ppmv toluene concentration to 630 ppmv at a 10 second contact time. This level of buffering was insufficient to ensure complete removal in the downstream biofilter and the contact time was longer than desired. For this reason, using SMZ as a passive buffering system for the gas phase contaminants was not pursued further. In contrast to the SMZ results, GAC was found to be an effective adsorbent to handle the peak contaminant concentrations that occur early during the SMZ regeneration ...
Date: March 11, 2005
Creator: Kwon, Soondong; Darby, Elaine B.; Chen, Li-Jung; Katz, Lynn E.; Kinney, Kerry A.; Bowman, R. S. et al.
Partner: UNT Libraries Government Documents Department

Biological determinants of photobioreactor design. Quarterly report No. 7, April 1, 1995--June 30, 1995

Description: The photosynthetic conversion of light energy into algal biomass in large-scale cultures is controlled by the availability of light, the photosynthetic machinery of algae, nutrients, temperature and the design characteristics of the culture system. For the situation in which light is made the growth rate limiting factor, there is an upper limit in the light conversion efficiency of a large-scale culture, which translates to a maximum potential yield of 30-40 g dry weight m-2 day-1 under ideal light conditions. The development of large-scale mass cultures involves many considerations, but the two major design parameters for optimizing yields at a particular time are the flow rate throughout the culture and the depth of the culture.
Date: April 1, 1997
Creator: Palsson, B.O. & Brown, G.G.
Partner: UNT Libraries Government Documents Department

A low-energy continuous reactor-separator for ethanol from starch, whey permeate, permeate mother liquor, molasses or cellulosics. Project final report, April 1, 1994--February 28, 1997

Description: In this project, a novel bio-reactor technology in which reaction is coupled with product separation was developed to pilot/demonstration scale. Combining reaction with separation during a fermentation allows the fermentation of highly concentrated feeds and allows the fermentation of streams with high levels of salts/non-fermentable inhibitors. Simultaneous saccharification and fermentation of polysaccharides such as starch and cellulose can also be combined with ethanol separation in the Continuous Stirred Reactor Separator (CSRS). Application of the bio-reactor to various substrates was investigated on a lab scale with fermentation of raw starch, cane molasses, xylose, whey permeate and permeate mother liquor. Flocculating yeast strains for high density sucrose/glucose fermentation were selected and adapted to form fast settling pellets. A strain of K marxianus capable of fermenting high salt permeate mother liquor was also selected and adapted. A low energy solvent ethanol recovery system was developed for ethanol recovery from the vapors leaving the reactor/separator. This Solvent Absorption/Extractive Distillation (SAED) process gives a low energy method for purifying the ethanol to an anhydrous product. The amount of energy needed to recover an anhydrous ethanol product from a CSRS stage running at 8% ethanol was calculated to be under 8,000 BTU/gallon. This process may also have further application in VOC (volatile organic carbon compounds) removal from air streams. During this project, a 24,000 Liter CSRS was designed, fabricated, installed, and operated at a small batch ethanol plant (Permeate Refining Inc) in NE Iowa. The reactor was operated on a semi-continuous basis over a period of 18 months. A Solvent Absorption Extractive Distillation (SAED) system was also recently completed and installed at the Permeate Refining Inc. site for ethanol recovery/dehydration.
Date: April 14, 1997
Creator: Dale, M.C. & Moelhman, M.
Partner: UNT Libraries Government Documents Department

Removal of heteroatoms and metals from crude oils by bioconversion processes

Description: The objective of this Cooperative research and Development Agreement project between Oak Ridge National Laboratory (ORNL) and Baker Performance Chemicals (BPC), Chevron, Energy BioSystems, Exxon, UNOCAL and Texaco is to investigate the biological desulfurization of crude oil. Biological removal of organic sulfur from crude oil offers an attractive alternative to conventional thermochemical treatment due to the mild operating conditions afforded by the biocatalyst. In order for biodesulfurization to realize commercial success, reactors must be designed which allow for sufficient liquid/liquid and gas/liquid mass transfer while simultaneously reducing operating costs. To this end we have been developing advanced bioreactors for biodesulfurization and have been studying their performance using both actual crude oil as well as more easily characterized model systems. This CRADA was originally established to be a 3 year program, but was extended to 5 years due to continuing interest. Because of business restructuring, UNOCAL, whose activities focused upon the supply and analysis of crude oil samples, was unable to continue its participation in the CRADA. Hence this report is designed to cover only LTNOCAL`s contribution to the CRADA as other aspects of the research are not yet complete. Experiments investigating the biological oxidative desulfurization of crude oil demonstrated that while dibenzothiophene like structures were readily degraded (>90% in 48 h) this desulfurization had minimal impact upon the total sulfur in the crude oil. This is because these structures represent less than 1% of the total sulfur found in the crude. Additional research is needed investigating sulfur speciation in crude oil with increased efforts upon broadening the sulfur specificity of the biocatalyst.
Date: October 1, 1997
Creator: Kaufman, E.N.
Partner: UNT Libraries Government Documents Department

Estimation of mass transfer and kinetics in operating biofilters for removal of VOCs

Description: Long-term, stable operation of trickle-bed bioreactors remains desirable, but is difficult to achieve for industrial processes, which generate continuous streams of dilute gaseous hydrocarbons. Mass transfer and kinetic parameters are difficult to measure, complicating predictive estimates. Two methods are presented which were used to predict the importance of mass transfer versus kinetics limitations in operating trickle-bed biofilters. Both methods altered the overall kinetic activity of the biofilter and estimated the effective mass transfer coefficient (K{sub 1}a) by varying the VOC (volatile organic contaminant) loading rate and concentration. The first method, used with developing biofilters possessing low biomass, involved addition of cultured biomass to the recirculating liquid to effect an overall change in VOC removal capacity. The second method altered the total bed temperature of a well-established biofilter to effect a change. Results and modeling from these experiments are presented for a mixed culture biofilter which is capable of consuming sparingly soluble alkanes, such as pentane and isobutane. Methods to control overgrowth are discussed which were used to operate one reactor continuously for over 24 months with sustained degradation of VOC alkanes with a rate of 50 g/h/m{sup 3}.
Date: November 18, 1997
Creator: Barton, J.W.; Davison, B.H. & Gable, C.C.
Partner: UNT Libraries Government Documents Department

Design and testing of a continuous metal biosorption system. Final report, March 10, 1994--June 9, 1995

Description: The research pursued in this project consisted of two portions that were conducted with constant coordination to allow the ultimate merger of research results. ORNL was assigned the task of developing the biomass portion of the bioreactor, while SCSC was responsible for the mechanical portions of the bioreactor. This report describes the technical aspects of a novel biological sorbent, consisting of microbial biomass immobilized within a polyurethane gel matrix, that was developed and characterized (on a bench scale, within batch and flow-through systems) for use in a novel, continuous-flow bioreactor system. The report also addresses an initial effort to develop a delivery technology that takes advantage of the specific characteristics of the biosorbent material to permits its deployment against contamination problems. The report concludes with recommendations for future work that would allow the designated wastes to be treated on a large scale.
Date: December 31, 1995
Creator: Faison, B.D.; Hu, M.Z.C.; Reeves, M.E.; McGraw, T.F.; Gupte, U. & Haris, W.G.
Partner: UNT Libraries Government Documents Department

Cometabolic bioreactor demonstration at the Oak Ridge K-25 Site: Final report

Description: The Oak Ridge National Laboratory (ORNL) conducted a demonstration of cometabolic technology for bioremediation of groundwater contaminated with trichloroethylene (TCE) and other chlorinated solvents. The technology demonstration was located at a seep from the K-1070-C/D Classified Burial Ground at the Oak Ridge K-25 Site. The technology demonstration was designed to evaluate the performance of two different types of cometabolic processes. In both cases, the TCE is cometabolized in the sense that utilization of a different primary substrate is necessary to obtain the simultaneous cometabolism of TCE. Trichloroethylene alone is unable to support growth and maintenance of the microorganisms. Methanotrophic (methane-utilizing) technology was demonstrated first; aromatic-utilizing microorganisms were demonstrated later. The demonstration was based on scaleup of laboratory and bench-scale prototype equipment that was used to establish the technical feasibility of the processes.This report documents the operation of the methanotrophic bioreactor system to treat the seep water at the demonstration site. The initial objectives were to demonstrate stable operation of the bioreactors and associated equipment, including the pretreatment and effluent polishing steps; and evaluate the biodegradation of TCE and other organics in the seep water for the three operating modes--air oxidation pretreatment, steam-stripping pretreatment, and no pretreatment.
Date: August 1, 1995
Creator: Lucero, A.J.; Donaldson, T.L.; Jennings, H.L.; Morris, M.I.; Palumbo, A.V. & Herbes, S.E.
Partner: UNT Libraries Government Documents Department