bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biological conversion of hydrogen sulfide into elemental sulfur
Authors: Basu R. , Clausen E. C. , Gaddy J. L. 
Published: February 2007

AbstractCurrently, hydrogen sulfide is removed from process gas streams by a series of reactions at high temperature to produce elemental sulfur in Claus, Stretford or other processes. These physicochemical processes have high intrinsic capital and operating costs, often are restricted by contaminants, and do not effectively remove all the H2S. As an alternative, the anaerobic, photosynthetic bacterium, Chlorobium thiosulfatophilum, has been demonstrated to convert hydrogen sulfide to elemental sulfur in a single step at atmospheric conditions. The autotrophic bacterium uses CO2 as the carbon source. Energy for cell metabolism is provided by incandescent light and the oxidation of H2S. A bench scale study has been performed in a CSTR equipped with a sulfur separator. Optimum process conditions have been achieved to maximize cell growth and elemental sulfur production. Near total conversion of H2S is achieved in a retention time of a few minutes. High concentrations of H2S or organics do not affect the culture. Sulfur recovery by settling is very efficient and near theoretical yields of sulfur are achieved. Economic projections indicate that sour gas can be desulfurized for $ 0.08‐0.12/MSCF.
Remediating pesticide contaminated soils using solvent extraction
Authors: Sahle‐Demessie Endalkachew , Meckes Mark C. , Richardson Teri L. 
Published: February 2007

AbstractBench‐scale solvent extraction studies were performed on soil samples obtained from a Superfund site contaminated with high levels of p,p′‐DDT, p,p′‐DDD, p,p′‐DDE and toxaphene. The effectiveness of the solvent extraction process was assessed using methanol and 2‐propanol as solvents over a wide range of operating conditions. It was demonstrated that a six‐stage methanol extraction using a solvent‐to‐soil ratio of 1.6 can decrease pesticide levels in the soil by more than 99% and reduce the volume of material requiring further treatment by 25 times or more. The high solubility of the pesticides in methanol resulted in rapid extraction rates, with the system reaching quasi‐equilibrium state in 30 minutes. The extraction efficiency was influenced by the number of extraction stages, the solvent‐to‐soil ratio, and the soil moisture content.Various methods were investigated to regenerate and recycle the solvent. Evaporation and solvent stripping are low cost and reliable methods for removing high pesticide concentrations from the solvent. For low concentrations, GAC adsorption may be used. Precipitating and filtering pesticides by adding water to the methanol/pesticide solution was not successful when tested with soil extracts.
Recovery of fuels and chemicals through catalytic pyrolysis of plastic wastes
Authors: McIntosh Michael J. , Arzoumanidis Gregory G. , Brockmeier Frederick E. 
Published: February 2007

AbstractThe effects of various promoted and unpromoted mixed oxide catalysts on yields and compositions of liquid organic products as measured in a small laboratory pyrolysis reactor are reported. While such small‐scale results do not accurately predict process plant yields, they provide a useful reference in preliminary economic evaluations and in planning larger‐scale tests. Therefore, on the basis of laboratory results, a commercialscale catalytic pyrolysis plant for the production of synthetic crude oil was simulated by using Aspen Plus and the economics were developed. Depending on certain assumptions, such a process could be profitable. To test the possibility of producing chemicals, a separations plant was added. Simulation results again suggested potential economic viability.
Composting of a heavy oil refinery sludge
Authors: Milne B. J. , Baheri H. R. , Hill G. A. 
Published: February 2007

AbstractPreliminary experiments using a range of bulking agents, moisture contents, nutrients, cosubstrates and inocula were undertaken to determine suitable ingredients for the successful composting of a heavy oil refinery sludge. The best ingredients were then chosen for a detailed study of the CO2 evolution rate and Total Petroleum Hydrocarbon (TPH) reduction versus time during the composting process. The initial TPH content of the refinery sludge was found to be 30% (mainly C15‐C30), two thirds of which were saturates and aromatics that were thought to be biodegradable. The results show a significantly higher TPH reduction using Solv‐II (55% reduction) as a bulking agent/nutrient source compared to heat‐treated peat moss and barley straw (both at 30% reduction). The CO2 evolution was high with Solv‐II and barley straw indicating the presence of high microbial activities in those composters.
Twenty years of site remediation via incinceration in the united states
Authors: Acharya Prakash , Pfrommer Charles 
Published: February 2007

AbstractDuring the mid‐1970s, the U.S. Environmental Protection Agency (EPA) Office of Research and Development conceptualized and began development of a mobile incineration system that could be used for the cleanup of spilled hazardous materials or of abandoned dump sites. Based on the development and demonstration of the EPA mobile incinerator, private industry developed their own mobile systems. As the need to clean up large Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA) sites progressed and as the market became more competitive, the “mobile” concept developed into a “transportable” concept with the systems becoming much larger than the initial EPA system.
A simple method for estimating cyclone efficiency
Authors: Overcamp Thomas J. , Mantha Sridhar V. 
Published: February 2007

AbstractA simple method for estimating cyclone efficiency is given based on the assumptions of a lognormal size distribution and the generalized Lapple fraction efficiency curve. This method enables the prediction of the overall efficiency of the cyclone as a function of the cut diameter of the cyclone, a parameter in the generalized Lapple distribution, and the parameters of the lognormal distribution. The method shows the most significant parameter in predicting the overall efficiency for a lognormal dust is the ratio of the aerodynamic geometric mass mean diameter to the aerodynamic cut diameter.
Aqueous absorption of nitric oxide induced by sodium chlorite oxidation in the presence of sulfur dioxide
Authors: Yang Chen‐Lu , Shaw Henry 
Published: February 2007

AbstractThe absorption of NO from a gas stream containing SO2 by aqueous solution of NaClO2 was studied in a bench scale scrubber. NOx removal of up to 95% was obtained using a packed bed scrubber. The corresponding SO2 removals were 100%. Experiments were also conducted in a bubble column and a spray chamber scrubber in order to obtain engineering data for scale‐up and process design. A novel UV/Vis photodiode array (PDA) method was developed for real‐time monitoring of oxychlorine compounds in the scrubbing solutions. As a consequence of the data obtained with the PDA system, a much better understanding of the chemistry of the scrubbing system has led to a simpler mass transfer model than is available in the literature. Absorption rates are reported in terms of overall reaction rates for a spray chamber scrubber and height of transfer units for a packed bed scrubber.
Preparation of calcium silicate absorbent from recycled glass
Authors: Arthur Lia F. , Rochelle Gary T. 
Published: February 2007

AbstractCalcium silicate hydrates were prepared from hydrated lime and post‐consumer recycled glass in an aqueous slurry. These high surface area solids have shown promise as alkaline sorbents for environmental gas cleaning applications. Surface area was monitored at a variety of reaction conditions. The rate of surface area formation was found to be directly proportional to the initial surface area of the glass. At 92°C, the addition of gypsum to the system had a significant positive effect, forming solids with surface areas up to 125 m2/g over long reaction times. Increasing the temperature from 92°C to 120°C increased the initial rate of surface area formation, however the rate decreased over time and the ultimate surface area was higher at 92°C. The addition of gypsum or calcium chloride to the reaction at 120°C increased the ultimate surface area, but not to the extent of the 92°C product. Up to a surface area of ∼100 m2/g, sorbents formed at 92°C with gypsum were not affected by agitation, nor by solids content between 20–50% under non‐agitated conditions. At reaction times after this point, surface area increased slightly with water content and more significantly with agitation. In addition, the dissolution of silica from glass was measured and was found to be faster than the rate of sorbent formation.
Life cycle assessment in the steel industry
Authors: Chubbs Scott T. , Steiner Bruce A. 
Published: February 2007

AbstractLife cycle assessment (LCA) is a means to analyze the environmental implications of product and service systems. As defined by international standards, the framework of LCA includes four distinct elements. The elements are goal and scope definition, life cycle inventory analysis, life cycle impact assessment, and life cycle interpretation. Although the LCA elements are at different stages of development, increased interest in the use of LCA will help fuel advancement of the science.The steel industry is gaining valuable experience in the use of LCA. The American Iron and Steel Institute (AISI), with members a LCA program in 1994. The program centers on training and education, conducting studies of steel products, participating in LCA projects which include steel, and promoting the development of LCA.The LCA program at AISI has proven to be successful. Over ten AISI member companies are directly participating in the effort, with even more companies represented at training and education events. LCA Projects in which AISI is active include an international steel industry study, a North American auto‐mobile industry benchmark study, and application of LCA to waste management activities.
An adsorption process for metal recovery from acid mine waste: The Berkeley Pit problem
Authors: Deorkar N. V. , Tavlarides L. L. 
Published: February 2007

AbstractAn adsorption process comprised of inorganic chemically active adsorbents (ICAAs) has been developed for recovery of Fe(III), Cu(II), Zn(II), Cd(II) and Pb(II) from acid mine drainage solutions similar to the Berkeley Pit near Butte, Montana. ICAAs are prepared by immobilization of chelating agents on the ceramic supports. The detailed laboratoryscale studies are executed to determine selectivity and operating conditions of each ICAA for individual metal ions. This paper presents results of separation studies using several ICAAs materials with simulated acid mine drainage solutions similar to the Berkeley Pit. Three most suitable ICAA materials have the potential to remove and recover desired metal ions from acidic streams without neutralization. Accordingly, an integrated adsorption process with three independently operating stages can be devised. Three fixed‐bed adsorbers, comprised of ICAA(A), ICAA(C), and ICAA(D), selectively removed Fe(III), Cu(II), and Zn(II) Cd(II) and Pb(II) respectively, from the acidic stream. In addition, the last bed, comprised of ICAA(D), acts as an acid scavenger and increases the pH of the effluent to greater than 7, which can then be discharged in an environmentally safe manner. The adsorbed metal ions can be recovered as pure metal salts by stripping with sulfuric acid, and the regenerated bed can then be used for future cycles.
Investigative and management techniques for cement kiln dust and pulp and paper process wastes
Authors: Peters Christopher S. 
Published: February 2007

AbstractKnowledge of the characteristics of industrial process wastes allows for some innovative and cost savings techniques for investigating and managing these wastes over conventional methods. This paper explores examples of some of these techniques employed on cement kiln dust (CKD) and pulp and paper mill process waste. Similar to Portland Cement, unleached CKD contains free lime and sources of reactive silica and/or alumina. Thus, it can “set up” in the presence of water. Properly moisture‐conditioned CKD has been successfully used in Michigan as a landfill liner and cover material on closures of old CKD piles and newly permitted fills. However, CKD also contains high concentrations of soluble salts and when improperly managed can generate a leachate with high total dissolved solid concentrations. Surface and downhole geophysical methods employing electromagnetic conductivity have proven effective in delineating the horizontal and vertical extent of groundwater plumes caused by releases of CKD leachate.At one paper mill in alabama where dewatered filter cake had been placed in a lined solid waste facility, liquids that had migrated to the surface due to excessive gas pressures caused unstable working conditions at the surface. Large, vertical french drains and a horizontal drainage blanket consisting of geogrid and sand constructed over the existing waste resulted in dewatering and a substantial increase in waste stability, allowing a vertical expansion to proceed. At a kraft mill in the southeastern United States, a geotechnical investigation of a lime mud pond revealed that the stability of the unit would increase by construction of an overlying dike, thereby allowing a vertical expansion to proceed. Finally, laboratory testing and modeling of the behavior of paper mill sludges indicates that they can be used as a landfill cover with permeabilities equivalent to or better than compacted clay. In‐place closures of sludge impoundments and landfills have been approved and implemented in at least three states.
Emissions of hazardous air pollutants from aeration tanks
Authors: Zhu Hongwei , Keener Tim C. , Bishop Paul L. , Orton Tim L. , Wang Min , Siddiqui Kaniz F. 
Published: February 2007

AbstractRegulated under the 1990 Clean Air Act Amendments (CAAA), Publicly Owned Treatment Works (POTWs) need to inventory and control their hazardous air pollutant (HAP) emissions, primarily from the aeration tanks. The spatial characteristics of hazardous air pollutants in the form of volatile organic compounds (VOCs) from the aeration units of POTWs have been investigated by systematic monitoring and mathematical modeling. Using a verified off‐gas sampling system and CC‐MS analytical method, a large wastewater treatment plant has been tested to understand the air emissions from its aeration basins. Variations of VOC emissions along the length of the aeration units have been tested and modeled. Most VOCs have decreasing concentration profiles. A simple PFR model has been developed to obtain the spatial information of the VOC fate. This model can be easily used to validate model parameters and accurately simulate the process especially in the case where the aeration tanks are operated with varied airflow rates along the tank length. Using this simple model, air emissions can be accurately estimated and the simulation results are useful to support an emissions control analysis. This study also reveals that simple multiplication of measured off‐gas concentration and total airflow over‐estimates the overall emissions.
Sonochemical treatment of benzene/toluene contaminated wastewater
Authors: Thoma G. , Gleason M. , Popov V. 
Published: February 2007

AbstractStudies of the destruction of benzene and toluene in water were undertaken using ultrasonic irradiation in a parallel plate Near Field Acoustic Processor (NAP). This magnetostrictive system is capable of degrading both benzene and toluene in a continuous stirred tank reactor configuration. The reaction kinetics were characterized by first order rate constants for the disappearance of the parent compound; these ranged from 2.7 ×
1−3 to 3.7 × 10−2 mm−1 over an applied power density range of 0.6 to 3.6 watt mL−1 and target concentration of approximately 25 to 900 µM. The rate constant is shown to be inversely proportional to the target compound concentration, indicating higher order reaction kinetics. The conversion efficiency for the system was characterized through the “G” efficiency commonly used in radiation chemistry. The G efficiency ranged between 4 × 10−5 to 2.2 × 10−4 molecules destroyed per 100 eV of electrical energy drawn from the wall outlet. These values are comparable to those of other advanced oxidation processes. Suggestions are made regarding methods to improve this technology.
Biofiltration of benzene contaminated air streams using compost‐activated carbon filter media
Authors: Zhu Lichuan , Abumaizar Riyad J. , Kocher Walter M. 
Published: February 2007

AbstractThree laboratory‐scale biofilter columns were operated for 81 days to investigate the removal of benzene from a waste gas stream. The columns contain a mixture of yard waste and sludge compost as biomedia. Different amounts of granular activated carbon (GAC) are mixed with the compost in two of the three columns to evaluate the extent to which biofilter performance can be enhanced. The effects of different operating conditions on the performance of the removal of benzene from air were evaluated. More than 90% removal efficiency was observed for an influent benzene concentration of about 75 ppm and an air flow rate of 0.3 L/min. in all 3 columns under steady‐state conditions. Under most cases of shock loading conditions, such as a sudden increase in the air flow rate, or the benzene concentration in the influent, the biofilters containing GAC provided higher removal efficiencies and more stable operation than the biofilter containing compost only.
Pure air's advanced flue gas desulfurization clean coal project
Authors: Brown John R. 
Published: February 2007

AbstractPure Air's Advanced Flue Gas Desulfurization (AFGD) Clean Coal Project successfully completed four and a half years of operation in December 1996 at Northern Indiana Public Service Company's (NIPSCO) Bailly Generating Station. This project received a $60 million grant from the DOE Clean Coal II program. Included in this was a three year DOE demonstration period. The facility was designed, built and is owned and operated by Pure Air of Allentown, Pennsylvania, through it's project company, Pure Air on the Lake, Limited Partnership. The project met or exceeded all performance criteria. It has averaged 95.3% SO2 removal, 99.9% availability and produced high quality commercial gypsum during this four and a half year period. It demonstrated many advanced technology features including a single, large absorber module serving two boilers, a wastewater evaporation system, and air rotary sparger for oxidation, and a new technology for agglomerating gypsum. The AFGD system will continue to serve NIPSCO's Bailly Station for at least another 15_years under an Own & Operate contact. The project enabled NIPSCO to cost effectively achieve full system wide compliance with the Phase 2 emission requirements for SO2 of the Clean Air Act Amendments (CAAA) of 1990 almost eight years before the target date. The project was the recipient of the Outstanding Engineering Achievement Award from the National Society of Professional Engineers in 1993 and the 1993 Powerplant Award from Power magazine. The data presented in this paper is based on performance during the first three years of operation.
Paint spray booth design using recirculation/partitioning ventilation
Authors: Darvin Charles H. , Proffitt David , Ayer Jackie 
Published: February 2007

AbstractMany spray painting facility operators have been under pressure to reduce the discharge of volatile organic compound (VOC) emissions to the atmosphere. Some operators have been able to convert their operations to lower VOC containing paints and coatings such as powder coating, waterborne coating, and radiation cured coatings. However, because of the functional requirements for some painted surfaces, acceptable paints with low VOC content may not be available. Consequently, these manufacturers may require the continued use of the higher VOC content paint formulations.The control of emissions from paint booths has been considered not economically viable due to the cost of treating the high volume of polluted air exhausted from these sources. Studies conducted by EPA with various Department of Defense (DoD) services, however, have demonstrated that the cost associated with typical spray booth control system can be significantly reduced through the use of spray booth recirculation. Reductions of exhaust flow rates of up to 90 percent may be possible when using recirculation in properly designed and operated booths without concern for the industrial hygiene or fire safety issues often mentioned when discussing recirculating booths. This paper presents the results of the design and demonstration program of full scale recirculating spray paint booths installed and operated at the U. S. Marine Corps (USMC), Marine Corp Logistics Bases (MCLB) facility at Barstow, CA. It also summarizes the regulatory and safety design issues of recirculation spray booths.
Mercury capture by an activated carbon in a fixed‐bed bench‐scale system
Authors: Dunham Grant E. , Miller Stanley J. , Chang Ramsey , Bergman Perry 
Published: February 2007

AbstractThe control of mercury emissions for utility power plants may become important because of the Clean Air Act Amendments requirement that the U.S. Environmental Protection Agency (EPA) assess the health risks associated with these emissions [1]. One approach for mercury removal, whichmay be relatively simple to retrofit (compared to other methods [2–4]), is the injection of sorbents, such as activated carbon, upstream of existing particulate control devices. A study, sponsored by the Electric Power Research Institute (EPRI) and the U.S. Department of Energy (DOE), is being conducted at the University of North Dakota Energy & Environmental Research Center (EERC) to develop a sorbent‐screening test protocol, screen potential mercury sorbents in a bench‐scale fixed‐bed system, and provide data to support efforts to model mercury capture mechanisms. A proper protocol is required to establish repeatability of the results and ensure reproducibility of results between different labs. To date, elemental mercury tests have been completed with several sorbents and under various flue gas conditions. The carbon‐based sorbent used in this study was a lignite‐based activated carbon (LAC), commercially available from American Norit Co., Inc. This paper presents results from the more recent tests with the LAC sorbent and elemental mercury. The LAC sorbent has also been used by others as a baseline sorbent [5–7].
Automated model building and modeling of alcohol oxidation in high temperature water
Authors: Iyer Sadasivan D. , Joshi Prasanna V. , Klein Michael T. 
Published: February 2007

AbstractSoftware for the computer generation of kinetic models was exploited to construct a mechanistic kinetic model for alcohol oxidation in high temperature (300 ≤T/°C≤380) water. The complexities of the oxidation mechanism were captured by a detailed mechanism consisting of eight reaction families. These included hydrogen abstraction by oxygen, hydrogen abstraction by radical, β‐scission, non‐terminating radical reactions, isomerizations, decomposition, molecular addition and termination steps. The mechanistic model was generated computationally, using the graph theory notions where the molecules and radicals are represented as atomic connectivity matrices and the reactions as matrix operators. The free‐radical kinetics of C1‐C4 alcohols exhibited features of both gas‐phase combustion and liquid‐phase oxidation chemistry. The imposition of Evans‐Polanyi relationships for the associated rate constants provided a significant reduction in model parameters with little loss of predictive capability. Kinetic parameter vectors, one for each reaction family, obtained by optimizing the model predictions to pure‐component ethanol data provided a very good fit to pure component kinetics of other alcohols, as well as mixture kinetics.