bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adsorption/desorption characteristics of lead on various types of soil
Authors: Peters Robert W. , Shem Linda 
Published: February 2007

AbstractLaboratory studies were conducted to address the phenomena of adsorption/desorption of lead onto various types of soils, both in the absence and presence of the chelating agent, ethylenediaminetetraacetic acid (EDTA). The linear and Freundlich isotherm models provided adequate description of the adsorption/desorption behavior. Over the range of EDTA concentrations employed in the study (0.1 to 0.10M), no significant difference in the isotherm parameters was observed as a result of the applied EDTA concentration. The presence of EDTA significantly altered the adsorption/desorption behavior of lead on the soil, resulting in less of the metal being adsorbed. The soil with the higher silt/clay content had a greater amount of lead adsorbed onto it (as compared with the sandy soil).
Electrokinetic removal of selected heavy metals from soil
Authors: Pamukcu Sibel , Wittle J. Kenneth 
Published: February 2007

AbstractThe electrokinetic process is an emerging technology for in situ soil decontamination, in which chemical species, both ionic and nonionic are transported to an electrode site in soil. These products are subsequently removed from the ground via collection systems engineered for each specific application. Electrokinetics refer to movement of water, ions and charged particles relative to one another under the action of an applied direct current electric field. In a porous compact matrix of surface charged particles such as soil, the ion containing pore fluid may be made to flow to collection sites under the applied field.The work presented here describes part of the effort undertaken to investigate electrokinetically enhanced transport of soil contaminants in synthetic systems. The results of the laboratory study presented here indicate that electrokinetic enhancement of contaminant transport in soils is a viable technology; development of this technology for wide range of applications hinges upon better understanding of the transient chemical and physical processes during application of current through soil/contaminant systems.
Nitrous oxide sampling, analysis, and emission measurements from various combustion systems
Authors: Hulgaard Tore , Dam‐Johansen Kim 
Published: February 2007

AbstractNitrous oxide (N2O) emissions from various combustion systems was measured by use of two analytical methods, the performance of which was evaluated together with the sampling procedures. One analytical method is grab sampling followed by analysis by gaschromatography (GC). This procedure was found to give accurate results, provided SO2 and H2O were removed during sampling in order to avoid N2O formation in the sample. An evaluation of a continuous infrared N2O analyzer shows that it is a useful instrument if measures are taken to eliminate or adjust for interferences from CH4, SO2, H2O, and to a minor extent also from NH3. A considerable formation of N2O was found when a gas containing SO2 and NO was scrubbed in a weak acid solution.The sampling program from a variety of combustion systems revelas that N2O emissions usually are low (0–5 ppm) from the combustion of pulverized coal. The results from a gas turbine, a laboratory gas‐fired fiber burner, and a domestic oil combustor are also in the very low range, whereas emissions from combustion of straw or wood were slightly higher. Even higher emissions were observed from circulating fluidized bed combustion (CFBC), from which the level of emissions increased with decreasing combustion temperature and increasing excess air levels. Sampling inside the CFBC reactor showed that N2O formation is particularly rapid at the transition from reducing to oxidizing conditions at the secondary air inlet. Pilot plant experiments with the selective non‐catalytic reduction of NO by urea or ammonia resulted in a large increase in N2O emissions during the injection of urea, whereas almost no increase was found during the injection of ammonia.
Effectiveness of supplemental aeration and an enlarged first‐stage in improving RBC performance
Authors: Surampalli Rao Y. , Robert Baumann E. 
Published: February 2007

AbstractA full‐scale RBC plant having two parallel trains and treating combined municipal and industrial dairy waste was used to investigate the effectiveness of supplemental aeration and an enlarged first‐stage in improving RBC performance. Enlarged first‐stage was created by removing the baffles between the first two stages. One RBC train was used as a control and the other train was used to evaluate the combined effectiveness of supplemental aeration and an enlarged first‐stage. Composite wastewater samples were collected from influent and effluent of each RBC stage in both trains. Samples were analyzed for soluble COD and BOD5, ammonia nitrogen, and suspended solids. Wastewater temperature, pH and dissolved oxygen levels were measured in each stage. The study results indicate that it is possible to achieve higher organic loading rates and removal rates when RBC units are provided with supplemental aeration and enlarged first‐stage.
The fate of BDAT polynuclear aromatic compounds during biotreatment of refinery API oil separator sludge
Authors: Huesemann Michael H. , Moore K. O. , Johnson R. N. 
Published: February 2007

AbstractA 16 week laboratory study was conducted to assess the biotreatability of regulated (BDAT list) polynuclear aromatic compounds (PNA) in refinery API oil separator sludge. The three different treatments consisted of a biotic, nutrient amended, inoculated aerated slurry reactor, a second biotic oxygen‐sparged reactor, and a sterile, nitrogen‐sparged control. Naphthalene, anthracene, phenanthrene, and benzo (a) pyrene were completely biodegraded in the first 4 weeks in both biotic treatments. Chrysene disappeared within 4 weeks in the aerated bio‐reactor, whereas it required 16 weeks to degrade in the oxygen‐sparged reactor. Pyrene degraded only 30% in the aerated bioreactor and did not exhibit any significant concentration changes in the oxygen‐sparged reactor. Phenanthrene, chrysene, and pyrene concentration levels did not change significantly during the 16 week treatment period in the nitrogen‐sparged control reactor indicating the absence of stripping losses for these PNAs. By contrast, naphthalene, anthracene, and benzo (a) pyrene levels remained constant during the first 2‐4 weeks in the control but decreased to below detection limits (5 mg/kg) at the end of the treatment. It is not clear whether the disappearance of these compounds is due to stripping, irreversible sorption or some anaerobic/aerobic biodegradation processes. In conclusion, the aerobic biotreatment of refinery API oil separator sludge was successful in removing most BDAT PNA compounds. The reduced biodegradability of pyrene may be explained in terms of either the inherently low biodegradation rate of this compound or the limited bioavailability in the weathered oily sludge system.
Bioremediation of soils contaminated with bis‐(2‐ethylhexyl) phthalate (BEHP)in a soil slurry‐sequencing batch reactor
Authors: Irvine R. L. , Earley J. P. , Kehrberger George J. , Tod Delaney B. 
Published: February 2007

AbstractA bench‐scale study was conducted to assess the feasibility of bioremediating phthalate contaminated soil from a polyvinyl chloride manufacturing operation in New Jersey. A bench‐scale slurry reactor study which utilized l4C‐labeled bis‐(2‐ethylhexyl) phthalate (BEHP) demonstrated that approximately 50 to 60% of the carbon in BEHP was mineralized directly to CO2 by indigenous microbial flora, while the remaining 40 to 50% was converted into cell mass. Additional bench‐scale studies were conducted in Soil Slurry‐Sequencing Batch Reactors (SS‐SBR) to evaluate the impact of basic biotreatability parameters (e.g., nutrient requirements and seed acclimation) on the bioremediation of soil contaminated with high levels of BEHP and total petroleum hydrocarbons (TPH). Treatment efficiencies of greater than 96% for both BEHP and TPH were observed in slurry reactors supplemented with nutrients (e.g., 1.4 to 2.0 g N per kg dry soil and 0.16 to 0.4 g P per kg dry soil). BEHP concentrations were reduced from initial levels as high as 24,000 mg/kg to less than 230 mg/kg and TPH concentrations, from 8,000 mg/kg to 160 mg/kg.
Fundamentals of bioventing applied to fuel contaminated sites
Authors: Dupont R. Ryan 
Published: February 2007

AbstractBioventing entails the use of soil vapor extraction (SVE) systems for the transport of oxygen to the subsurface, where indigenous organisms are stimulated to aerobically metabolize fuel components. Bioventing systems are designed and configured to optimize oxygen transfer and oxygen utilization efficiency, and are operated at much lower flow rates and with configurations much different than those of conventional SVE systems. Bioventing system applications and design are contrasted to those of conventional SVE systems, and the two key elements of bioventing system design evaluation, i.e., in situ microbial activity and air permeability determinations, are highlighted in this paper. The application of bioventing to vadose zone bioremediation was reviewed with particular emphasis on its advantages over aqueous based bioremediation systems in terms of its superior oxygen transfer efficiency. Finally, the application of bioventing and bioventing design concepts are illustrated through a case study of JP‐4 jet fuel contaminated soil remediation at Hill AFB, Utah.
Limitations and practical use of a mass transfer model for predicting air stripper performance
Authors: Thom James E. , Byers William D. 
Published: February 2007

AbstractThe Onda Mass Transfer Model is widely used for predicting air stripper performance, yet reports of its reliability vary significantly. Researchers, who generally pay close attention to all aspects of a stripping column's design, construction, and operation, report results closely aligning with model predictions (± 30 percent). In practice, however, where design and construction details vary, much wider variations between field performance and model predictions are reported.This paper discusses design and construction issues that can contribute to performance problems in practice and lead to field deviations from model predictions. The design and construction issues of greatest importance include: liquid distribution, packing material, and adherence to the limitations and restrictions of the air stripping model used, in this case the Onda Model. Some less common problematic areas are also discussed, including: Henry's Law data, fouling, chemical reactions, and end effects.
Modeling the effects of plants on the bioremediation of contaminated soil and ground water
Authors: Davis L. C. , Erickson L. E. , Lee E. , Shimp J. F. , Tracy J. C. 
Published: February 2007

AbstractPlants have the potential for aiding in situ remediation of contaminated soil and groundwater by promoting microbial growth in the rhizosphere. Microbial populations vary in response to the presence of oxygen, water and metabolizable carbon sources. Plants are able to provide a favorable environment for microbe growth by providing a plant pathway for oxygen transfer to the soil, transferring water from saturated to unsaturated soil, and supplying supplemental substrate in the form of root exudates and decaying root hairs. Models of the physical, chemical, and biological relationships in the rhizosphere are reported. Simulation results are presented for a hypothetical vegetative buffer zone over a shallow aquifer. The fate of atrazine is simulated in order to investigate the effects of rainfall, evapotranspiration, atrazine uptake by plants, and atrazine adsorption to root surfaces on atrazine concentration at the downstream edge of the vegetative buffer zone.
Bed mixing and heat transfer in a batch loaded rotary kiln
Authors: Leger Christopher B. , Cook Charles A. , Cundy Vic A. , Sterling Arthur M. , Deng Xiao‐Xue , Lighty Joann S. 
Published: February 2007

AbstractA pilot‐scale rotary kiln simulator has been used to make experimental measurements of the thermal response of solids charged onto a preexisting bed of hot solids material. The measurements clearly show that the bed is not thermally uniform. Time constants for bulk heating and mixing were extracted from the measurements. A simple model is developed that correlates the time constant for mixing to bed turnover rate, allowing the thermal history of a charge of solids to be predicted based on measurable parameters of the kiln and bed. The measured and predicted thermal histories show that mixture greatly augments the initial rate of heat transfer to the fresh charge of solids. This is important because rapid heating of a fresh charge of solids could result in rapid evolution of volatile species.
Simultaneous removal of NO and SO2 in packed scrubbers or spray towers
Authors: Harriott Peter , Smith Kevin , Benson Lewis B. 
Published: February 2007

AbstractNitric oxide and sulfur dioxide can be removed from flue gas by scrubbing with a lime slurry containing ferrous EDTA. Tests in a 0.90m diameter column with several commercial packings gave 99 to 99.9 percent SO2 removal and 10 to 60 percent NO removal. The absorption of NO is controlled by the liquid‐film resistance, and the number of transfer units varies with the square root of the ferrous EDTA concentration, the 0.4 to 0.6 power of the liquid rate, and the − 1.0 power of the gas velocity, in agreement with predictions. The height of a transfer unit for NO absorption, corrected for end effects, was 10 to 15m, about 30 times the estimated values for SO2 absorption, which is gas‐film controlled. The spray tower gave lower removal rates for both gases, but the ratio of transfer units was about the same as for the packed columns.
Development of bacterial cultures which can metabolize structural analogs of dioxin
Authors: Rugge Carol D. , Ahlert Robert C. , O'Connor Owen A. 
Published: February 2007

AbstractWidely present in the environment, the highly‐toxic compound 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) has been found to resist microbial biodegradation. To develop an anaerobic biodegradation approach for soils and sediments contaminated with TCDD, methanogenic and denitrifying cultures were established on a variety of chloroaromatic substrates, including 2‐chlorophenol, 3‐chlorophenol, 4‐chlorophenol, 2,3‐dichlorophenol, 3,4‐dichlorophenol, 4,5‐dichlorocatechol and catechol, using an inoculum from Newtown Creek (New York, NY). Dehalogenation was observed, with monochlorophenols producing phenol and dichlorophenols producing monochlorinated phenols and phenol. Based on gas production, the chlorinated catechol did not appear to undergo biodegradation under any condition, while catechol was degraded under methanogenic conditions. Select cultures amended with a mixture of chloroaromatics and n‐butanol, a solubilizing agent, exhibited depressed gas production under both anaerobic conditions. Biodegradation of TCDD adsorbed onto particles of gallium oxide is under investigation with an amalgamation of the active single‐substrate methanogenic cultures.
Advanced coolside desulfurization process
Authors: Stouffer M. R. , Rosenhoover W. A. , Withum J. A. 
Published: February 2007

AbstractThis paper describes a dry sorbent injection SO2 abatement process with the potential to significantly enhance desulfurization performance over that of existing in‐duct injection technology such as the Coolside process. The Advanced Coolside process was developed by CONSOL Inc. and is being tested in a pilotscale project, partially funded by the U.S. Department of Energy (DOE). The goals of this process development effort are to increase the applicability of sorbent injection technology as a compliance option for coal‐fired boilers for the 1990 Clean Air Act Amendments and to reduce total process SO2 control costs. Specific performance objectives are to achieve 90% SO2 removal and 60% sorbent utilization efficiency, while retaining the low‐capital cost and retrofit advantages inherent to in‐duct sorbent injection technology. The Advanced Coolside process concept involves flue gas humidification to near the adiabatic saturation point combined with fly ash removal using a gas/liquid contacting device, followed by injection of a sorbent (e.g., Ca(OH)2) into the highly humid flue gas with collection by the existing particulate collector. High SO2 removal and sorbent utilization efficiency are possible with hydrated lime when the flue gas is nearly saturated with moisture. Sorbent utilization is further improved by recycle, and the potential for improvement by the use of recycle is increased with removal of the fly ash before sorbent injection. Further, testing indicates that pre‐treatment of the recycle sorbent before reinjection can improve process performance. Because flue gas is humidified completely before sorbent injection, the existing duct configuration may not limit process retrofit potential. The heat of reaction between SO2 and Ca(OH)2 heats the flue gas before the existing particulate collector. Current pilot test data indicate that the Advanced Coolside process performance objectives are achievable. On‐going process development work includes design optimization for the contacting device, improving efficiency of sorbent recycle, and optimization of sorbent performance.
Evaluation of the CombiNOx process at pilot scale
Authors: Newhall Pont J. , Evans A. B. , England G. C. , Lyon R. K. , Seeker W. R. 
Published: February 2007

AbstractUnder contract with the Deparment of Energy, EER is developing a NOx control process with potential to reduce NOx emissions from coal fired utility boilers by up to 85%. CombiNOx is a family of NOx reduction processes which involves the synergistic application of combinations of technologies such as staged combustion, reburning, selective non‐catalytic reduction (SNCR), and methanol injection. Any combination of these technologies can be applied to achieve a desired NOx reduction in a given boiler. Integration of these processes may be site‐specific depending on boiler configuration and required emission limits.
Economic effects of catalyst deactivation during VOC oxidation
Authors: Agarwal Sanjay K. , Spivey James J. 
Published: February 2007

AbstractCatalytic oxidation of volatile organic compounds (VOCs) is widely used for air pollution control. While catalytic oxidation offers several advantages over alternative processes, the catalyst can deactivate over time, resulting in changes in activity and selectivity with time‐on‐stream. To maintain constant catalyst activity, required for environmental regulations, the temperature is generally increased gradually to compensate for catalyst deactivation. This results in an increase in fuel consumption with time. Since the fuel costs can account for 50 to 70 percent of the total operating costs, the effect of catalyst deactivation on fuel costs and hence total operating costs should be considered. This paper shows how the catalyst deactivation affects the total operating costs using an example of the oxidation of a VOC‐containing gas stream over a commercial hopcalite catalyst.
Pilot scale study and design of a granular activated carbon regeneration process using supercritical fluids
Authors: Tomasko David L. , James Hay K. , Leman Gregory W. , Eckert Charles A. 
Published: February 2007

AbstractA technology which has great potential for environmental control and waste remediation is contaminant removal and separation with supercritical fluids (SCF's) or supercritical fluid extraction (SFE). Pressure tuning of solvent power allows SCF processes to adapt to a wide variety of small batch oriented separations typified by environmental cleanup operations.The ability of supercritical CO2 to extract model contaminant compounds from GAC and subsequently drop out most of the contaminant in a liquid phase has been investigated in a pilot scale apparatus. Typical desorption profiles indicate an 85% removal of the compound from the carbon which allows for reuse. The desorption results have been interpreted with a generalized desorption‐mass transfer model.The results of the pilot plant studies have been applied to the design of a fixedsite GAC regeneration unit consisting of a three‐element desorber with two‐stage flash separation. Optimization of the process centers around minimizing the cost of recycling the SCF through an efficient recompression scheme and cycle configuration in the desorber unit. An economic evaluation shows a processing cost of 10.6¢/lb (23¢/kg) GAC which compares favorably with thermal regeneration and incineration. This non‐destructive process allows re‐use of the GAC while maintaining a high adsorbate capacity, which reduces carbon replacement costs and significantly decreases the need for carbon disposal by landfill or incineration.
Hazardous waste source‐reduction study with treated groundwater recycling
Authors: Chang Li‐Yang , McCoy Benjamin J. 
Published: February 2007

AbstractA feasibility study is presented for modifying electroplating processes for source reduction. Ion exchange and reverse osmosis units are suggested to allow reclaiming and recycling of metal solutions. A particular example of water conservation in an electroplating shop is presented for the treatment and utilization of groundwater contaminated by hydrocarbon chemicals, including volatile organic compounds (VOCs) and gasoline products. Granular carbon adsorption, UV oxidation, and demineralization steps and alkalinity control measures for the groundwater are discussed. Engineering and economic analyses provide a basis for comparing alternative designs. An integrated scheme, including groundwater remediation and source reduction, is feasible for the plating shop. The removal of VOCs and demineralization of the polluted groundwater are important steps. With the integrated plan, 90% removal or recovery of heavy metals can be achieved, and water usage and wastewater can be reduced by 90%. Thus, it is feasible to prevent water pollution at the source and to recycle treated groundwater and wastewater for the manufacturing process.
Hydrophobic zeolite adsorbent: A proven advancement in solvent separation technology
Authors: Blocki Stephen W. 
Published: February 2007

AbstractWith the passage of the Clean Air Act Amendment (CAAA) of 1990, solvent emission regulations continue to become ever more stringent. An ongoing and increasingly strong incentive exists to develop and apply to the solvent emission control industry more efficient and cost effective control technologies.This paper presents a new technology used for solvent separation and concentration, hydrophobic zeolite adsorbent. Because of its unique physical properties, solvent control systems using hydrophobic zeolite may exhibit separation capacity equal to or better than systems using activated carbon without requiring much of the support equipment. Though activated carbon remains the adsorbent of choice for many applications, hydrophobic zeolite represents an efficient alternative for many niche applications. Extensive tests have proven its capabilities and the results are presented here.Also presented is the modular solvent concentrator (MSC) designed to handle up to 50,000 scfm (79,000 Nm3/h)—up to 50% more air flow as current concentrators—in the same area. The MSC is flexible enough to handle any currently available adsorbent. Several case studies are presented to illustrate use of hydrophobic zeolite as well as the MSC.