bluuebunny/crossref_metadata_2025_split huggingface dataset:
Removal of heavy metals in POTW
Authors: Aulenbach Donald B. , Meyer Michael A. , Beckwith Eileen , Joshi Shrikant , Vasudevan Chittibabu , Clesceri Nicholas L. 
Published: February 2007

AbstractStudies were conducted at three activated sludge treatment plants during normal operation. The heavy metals on the priority pollutants list were measured in the influent to each plant, the primary sedimentation effluent where applicable, the discharge after activated sludge treatment and secondary sedimentation, and in one case after a final polishing filter. Both the soluble and the total portions were measured.Beryllium, nickel, and thallium were not found in detectable levels in any of the plant influents. Mercury was found in only trace amounts. The removals of the other metals varied considerably. No consistent conclusions can be made from the data; each metal, soluble or total fraction, and unit treatment operation must be interpreted individually. The only metal in the plant effluents consistently above the recommended limit was arsenic, and this barely above the limit. The only other metal present in the effluent above the recommended limit was the lead content from Fitchburg, despite 83% removal of this metal in the treatment system.
Removal of heavy metals in wastewater in a clay soil matrix using electro‐osmosis
Authors: Ray Chittaranjan , Ramsey R. H. 
Published: February 2007

AbstractThe feasibility of using electro‐osmosis for removal of heavy metals (Cd, Cu, and Pb) contained in aqueous solutions was examined using soil cores formed from Randall clay — a clay found in Playa lake basins in the High Plains of West Texas. Initially, sorption tests were conducted with the clay dispersed in the metal solutions of interest to determine if adequate sorption would take place. The retention capacity of the clay for Cd was found to be 0.0083 mg/mg of soil. (105 kilograms of Cd could be removed in top one‐meter depth of a hectare of Randall clay with a bulk density of 1.4 g/cm3).Electro‐osmosis was found to increase the permeability of the clay but was found to be both a slow rate system (up to 225 days to remove one pore volume of water through a m3 of soil) and energy intensive (1.44 × 105 kJ to 8.1 × 105 kJ per m3 of drained water). Problems noted during the test that need solution before further experimentation with this procedure include selection of less corrodible materials for electrodes, prevention of electrolysis of water at potential gradients needed to move the waters being treated through the soil matrix, and control of ion gradients from the anode to the cathode reservoir to prevent backflow episodes from reversing flow from the cathode to the anode region.
H2S/SO2 removal in the modified‐claus reaction over packed alumina beds
Authors: Chou C.‐L. (Joe) 
Published: February 2007

AbstractThe removal of H2S and SO2 by the modified‐Claus reaction was studied in a computer‐controlled packed bed system over activated alumina catalyst. The reactor system consisted of two 6.35 × 60.96 cm reactors in parallel and was designed to allow for the axial temperature monitoring and side stream sampling. The H2S/SO2 conversion efficiencies were‐evaluated against gas‐hourly space velocity (GHSV) ranging from 100 to 12,000 1/hr at the three typical Claus converter conditions for three sizes of Alcoa S‐100 Claus catalyst. The conditions for defining the kinetic and thermodynamic regimes of the modified‐Claus reaction were reported. The thermodynamic regime was checked and confirmed by the equilibrium predictions of a computer program utilizing the principle of minimization of Gibbs free energy. The possible rate‐controlling mechanism in the kinetic regime and the effects of water vapor on the reaction were discussed.
Removal of dissolved organic contaminants by ozonation
Authors: Yurteri Coskun , Gurol Mirat D. 
Published: February 2007

AbstractThis article focuses on the use of ozone for the elimination of dissolved organic pollutants from water and wastewaters. The physical and chemical phenomena prevailing during the contact of a polluted liquid stream with gaseous ozone‐air or ozone‐oxygen mixture in empty or packed columns is represented mathematically. The simulation procedure is based on defining the concentration profiles of ozone and the organic solutes in both liquid and gas phases by means of differential mass balances. Methods for the determination of necessary model parameters is outlined and the model is analyzed for its sensitivity to various process variables.
Hazardous waste minimization and management at an R&D laboratory
Authors: Boortz M. J. 
Published: February 2007

AbstractChevron Richmond Research Center (RRC), located in Richmond, California, conducts research and technical service in the fields of petroleum and petrochemical products, processes, and related matters. To assure proper disposal of all wastes generated, RRC has implemented a unique waste disposal system. The system entails the use of specific disposal procedures and color‐coded waste receptacles for the different types of wastes. Communication with employees is vital for successful use of the waste disposal system. A written waste mangement plan documents the achieved and the projected reductions in wasted generation. Most of the hazardous waste reductions realized prior to 1989 were from installation of equipment and offsite recycling. Much of the future reductions are expected to come from changes in laboratory procedures and practices. The ultimate goal is to increase employee environmental awareness so that waste minimization is a routine part of every job.
Use of an air inflated dome to control VOC emissions from an aeration lagoon
Authors: Joffe Lawrence B. 
Published: February 2007

AbstractIn 1979, the Upjohn Company entered into negotiations with the State of Conecticut for renewal of their NPDES permit. During these negotiations, control of odors from the site became an issue, and several methods of eliminating potential odor sources from the facility were examined. At this point in time, the waste treatment system consisted of a series of lagoons, the last one being an aeration lagoon with two 150 horsepower fixed aerators. One of the many potential odor sources to be addressed was this lagoon. As part of the permit renewal conditions, the State of Connecticut DEP ordered Upjohn to construct an air supported enclosure over the 9,500–11,350 m3 aeration lagoon. Exhaust air was to be monitored and treated with the use of fixed bed granular activated carbon absorbers. This resulted in a project costing over $620,000 to construct and an additional $75,000–$100,000 per year to operate.
Bench–scale evaluation of calcium sorbents for acid gas emission control
Authors: Jozewicz Wojciech , Chang John C. S. , Sedman Charles B. 
Published: February 2007

AbstractCalcium sorbents for acid gas emission control were evaluated for effectiveness in removing SO2/HCl and SO2/NO from simulated incinerator and boiler flue gases. All tests were conducted in a bench‐scale reactor (fixed‐bed) simulating fabric filter conditions in an acid gas removal process. Reagent grade Ca(OH)2 was used to establish baseline sorbent performance. The reactivity of reagent grade Ca(OH)2 with HCl from SO2/HCl mixtures gradually increased with decreasing approach to saturation temperature. SO2 reactivity toward Ca(OH)2 was very sensitive to approach to saturation. Novel calcium silicate sorbents were tested for reactivity with both SO2 and HCl. A “thermal window” for optimum NO removal was found at 90°C (194°F) when Ca(OH)2 was used at SO2/NO ratios of 1:1. Reactivity of Ca(OH)2 toward SO2 from SO2/NO mixtures was very sensitive to approach to saturation, while reactivity with NO was insensitive. Several additives were subsequently tested to determine optimum sorbent combinations for SO2/NO control. To date the most promising additives are Mg(OH)2 and Na2HPO4 at 10 mol percent concentrations. As with SO2/HCl, calcium silicate has been shown to be superior for SO2/NO capture. Some implications for larger‐scale process configurations and sorbent selection for HCl/SO2/NO control are discussed. Future activities and limited larger–scale pilot plant results are also discussed.
Sorbent and ammonia injection at economizer temperatures upstream of a economizer temperatures upstream of a high—temperature baghouse
Authors: Chu Paul , Downs Bill , Holmes Bob 
Published: February 2007

AbstractThe current technology of choice—world–wide—for post–combustion NOx control is selective catalytic reduction (SCR) with ammonia. The application of SCR to coal–fired units has proven to be somewhat more difficult than its application to natural gas and oil–fired units due to SO2 poisoning of the catalyst, catalytic oxidation of SO2 to SO3, and erosion and fouling of the catalyst by fly ash [1]. These problems could be potentially diminished if SO2 and particulate removal systems were placed upstream of the SCR reactor. However, this is not easily accomplished since SCR systems operate best in the temperature range of 600°F–800°F (315°C–425°C). Several SCR installations in Europe employ conventional flue gas desulfurization (FGD) and particulate control upstream of flue gas reheat and SCR. However, the flue gas reheat typically imposes a 1%–2% energy penalty [2]. Several recent technical developments now offer a technology whereby these limitations of SCR for coal applications can be alleviated.These technical developments are in the areas of high temperature filtration, improved SCR catalysts, and advances in sorbent injection. These advances have been incorporated into a patented process known as the SOxNOxRox Box™ (SNRB) process. Briefly, this process consists of a “hot” baghouse employing woven ceramic fabric bags, a zeolite SCR catalyst incorporated into the baghouse, and the injection of either calcium–or sodium–based sorbent upstream of the baghouse (see Figure 1).This paper deals with the status and development of the SNRB process, including some results from recently completed pilot–plant tests performed under a contract with the Ohio Coal Development Office (OCDO).
Cleanup of contaminated soils by pyrolysis in an indirectly heated rotary kiln
Authors: Schneider Dietmar , Beckstrom Blake D. 
Published: February 2007

AbstractThe destruction of hazardous waste and cleanup of contaminated soils by pyrolysis in an indirectly heated rotary kiln system, followed by combustion of the volatiles in a secondary combustion chamber, has been tested in a pilot plant and demonstrated in an industrial scale plant. Deutsche Babcock Anlagen AG conducted comprehensive tests in a pilot plant with throughput rates of 0.5 to 1 ton/hour. Following these tests, Deutsche Babcock designed and constructed the industrial scale demonstration plant with a throughput rate of 7 tons/hour for Bergbau AG Westfalen near Dortmund, West Germany.
Performance of selected in situ soil decontamination technologies: An Air Force perspective
Authors: Downey Douglas C. , Elliott Michael G. 
Published: February 2007

AbstractEvery year, the U.S. Air Force stores and transfers three billion gallons of JP‐4 jet fuel. Unfortunately, not every gallon of fuel has been consumed in flight. Fuel spills account for nearly half of the chemically contaminated sites on Air Force installations and that percentage is growing as underground storage systems are more closely inspected. The Air Force Engineering and Services Laboratory is responsible for developing and testing new and more cost effective technologies capable of cleaning up fuel spills in a variety of soil and groundwater conditions. Special emphasis has been placed on soil decontamination because our sampling data has confirmed that the majority of spilled fuel is adsorbed or occluded in the soil above the water table.
In situ biodegradation of TCE contaminated groundwater
Authors: Nelson Michael J. , Kinsella John V. , Montoya Terry 
Published: February 2007

AbstractTrichloroethylene (TCE) is one of the most widely used chlorinated solvents; it is also a common groundwater contaminant. TCE–contaminated groundwater is presently treated by transferring the solvent either to a solid (carbon adsorption) or to the atmosphere (air stripping). Biological treatment of the contaminated water is an alternative that causes complete destruction of the solvent. When performed within the aquifer it is termed in situ biotreatment. A specific strain of bacteria (G4) has been isolated that degrades TCE enzymatically. The process has been extensively tested in the laboratory and confirmed in a field pilot test. The pilot test involved the injection of a clean, oxygenated water stream directly into the TCE plume. Nutrients and G4 were added to the injection stream and TCE concentrations were measured up–and downgradient of the injection well.A decline in TCE levels was observed eight hours after injection and continued for the following ten days. TCE concentrations were reduced from a high of 3,000 ppb to a mean value of 78 ppb during a 20 day period.
Bioturbation: A facilitator of contaminant transport in bed sediment
Authors: Bosworth Weldon S. , Thibodeaux Louis J. 
Published: February 2007

AbstractThe biological activity of benthic organisms (=bioturbation) in bed sediments can be significantly more important than physicochemical processes in the movement of sediment particles and interstitial constituents within the sediment column and to the overlying water. Bioturbation‐driven transport processes may be several orders of magnitude more rapid than molecular‐driven processes for some constituents, i.e., particle reactive compounds like PCB, when considered on a chemical pore water concentration gradient basis. Benthic organisms affect particle redistribution and solute transport by burrowing, ingestion/excretion, tube‐building and biodeposition. In most benthic environments, whether freshwater, estuarine or marine, numbers of organisms and rates of sediment turnover are highest in the oxygenated zone above the redox boundary, generally the top 2–5 cm of the sediment column. However, a variety of organisms penetrate deeper into the sediment and may also be important in transport of both dissolved and particle reactive constituents. When considering capping of contaminated sediment in place or capping of contaminated dredge spoils, the effects of bioturbation on the mobility of the contaminants must first be considered before establishing engineering design criteria. Capping of contaminated bed sediments or dredge spoils can elevate the bioturbated zone above the contaminated bed sediment and thus potentially reduce the rate of contaminant transport by several orders of magnitude.
Homogeneously catalyzed oxidation for the destruction of aqueous organic wastes
Authors: Leavitt David D. , Horbath Joe S. , Abraham Martin A. 
Published: February 2007

AbstractSeveral organic species, specifically atrazine, 2,4‐dichlorophenozyacetic acid, and biphenyl, were converted to CO2 and other non‐harmful gases through oxidation catalyzed by inorganic acid. Nearly complete conversion was obtained through homogeneous liquid‐phase oxidation with ammonium nitrate. The kinetics of reaction have been investigated and indicate parallel oxidation and thermal degradation of the oxidant. This results in a maximum conversion at an intermediate temperature. Increasing oxidant concentration accelerates the rate of conversion and shifts the location of the optimum temperature. Reaction at varying acid concentration revealed that conversion increased with an approximately linear relationship as the pH of the solution was increased. Conversion was increased to greater than 99% through the addition of small amounts of transition metal salts demonstrating the suitability of a treatment process based on this technology for wastestreams containing small quantities of heavy metals.
Adsorption of benzene from aqueous solutions by bentonite treated with quaternary amines
Authors: Cadena Fernando , Garcia Ramiro , Peters Robert W. 
Published: February 2007

AbstractThe adsorptive properties of Wyoming bentonite, which has been tailored using various tetraalkylammonium (TAA+) ions, have been investigated for the selective removal of hazardous organic pollutants found in waters and soils contaminated by petrochemical spills. The effectiveness of the tailoring agents is evaluated by comparing the adsorption isotherms of benzene on both treated and untreated soils. Five TAA+‐type compounds are investigated: ammonium (NH4+), tetramethylammonium (TMA+), tetraethylammonium (TEA+), tetrapropylammonium (TPA+), and tetrabutylammonium (TEA+). The optimum dose characteristics are determined for each tailoring cation. The adsorption capacity of the treated clay decreases for doses that exceed the optimum dose because of the increase in organic content in solution, which induces a reduction in the partition coefficient between organically coated solid and the liquid phase. Despite the similarity in nature of the TAA+ cations used in this study, significant differences in the adsorption capacities are obtained for the various compounds.
Thermal treatment for the removal of PCBs and other organics from soil
Authors: Fox Robert D. , Alperin Edward S. , Huls Hubert H. 
Published: February 2007

AbstractThermal separation is an emerging technology for the treatment of contaminated soils and solids. The process removes organic contaminants by indirectly heating the soils and olids to temeratures sufficient to vaporize the harazdous components. The organic vapors in the desorber off‐gas are treated either by oxidation in a RCRA‐standard secondary combustion chamber or by condensation and conventional treatment of the small amount of the resultant condensate.This process had its first successful pilot demonstrations in treating Herbicide Orange contaminated soils at the Naval Construction Battalion Center and at Johnston Island, where dioxin contamination was reduced to less than 1 ppb.This paper summarizes the results of a series of pilot tests, conducted under a TSCA R&D permit, on 3 soils contaminated with PCBs at concentrations ranging from 250 ppm to 4%. To demonstrate the process on an engineering scale, IT made 13 runs in the pilot thermal separator at rates ranging from 18 to 32 kg/hr. Reported are results on the effect of temperature and residence time on the quality of treated soil. The report also summarizes pilot results on a mixed waste soil and soils contaminated with PAHs.
Design and testing of a moving bed VOC adsorption system
Authors: Larsen Eric S. , Pilat Michael J. 
Published: February 2007

AbstractA 0.28‐2.8 m3/min (10‐100 cfm) moving bed carbon adsorption pilot plant has been developed for testing of low (10–200 ppm) concentration VOC emissions. The pilot plant uses a cross‐flow arrangement with the air flowing horizontally through the adsorption bed while the carbon adsorbent particles flow vertically downward. At the bottom of the system, the “used” activated carbon is regenerated using a direct contact heat exchanger. The regenerated carbon is then transported to the top of the moving bed via a screw feeder and pneumatic transport tube. A small gas flow containing the VOCs removed from the used adsorbent is emitted continuously from the adsorbent regenerator. When a carbon flow rate of 2.3 kg/hr (5 lbs/hr), a face velocity of 0.32 m/sec (63 ft/ min), and an emissions stream containing 30 ppm ethanol were used, the observed collection efficiency was approximately 90%. The ability to regenerate the carbon was tested by first operating the system in a static mode, that is air being drawn into the system while the adsorption bed was not moving. This was continued until approximately 70% of the inlet gas VOCs passed through the system without being adsorbed. The carbon flow was then started and the VOC concentration in the off gases of the absorbent regenerator was measured as the partially saturated carbon passed through the system. The VOC concentration in the gases emitted from the adsorbent regenerator was about a factor of ten higher than the VOC concentration in the air entering the adsorption bed.
Legal incentives for minimizing waste
Authors: Clearwater Scott W. , Scanlon Joanne M. 
Published: February 2007

AbstractWaste minimization, or pollution prevention, has become an integral component of federal and state environmental regulation. Minimizing waste offers many economic and public relations benefits. In addition, waste minimization efforts can also dramatically reduce potential criminal requirements. This paper addresses the legal incentives for minimizing waste under current and proposed environmental laws and regulations.
Nucleation and crystal growth of calcium sulfite hemihydrate
Authors: Gleason Cynthia L. , Rochelle Gary T. 
Published: February 2007

AbstractIn slurry scrubbing processes for flue gas desulfurization the precipitation rate of calcium sulfite affects scrubber solution composition, SO2 absorption, sulfite oxidation, and limestone utilization. Sludge quality and disposal costs are also a function of precipitation kinetics. The nucleation and crystal growth rates of calcium sulfite hemihydrate were measured in a continuous flow crystallizer at conditions that produced agglomerate crystals. At 28 and 55°C, the nucleation rate, B°, varied from 0.25 to 23 × 108 #/m3‐sec and was given at pH 5.5 by the correlation:

The suspension density, MT, was varied from 7 to 90 kg/m3. The linear growth rate, G (m/sec), varied from 0.5 to 9 × 10−9 m/s as residence time was varied from 42 to 360 minutes. The nucleation rate constant had a maximum near pH 5.5 and was about 50% lower at pH 4.2 and pH 6.5. Gypsum saturation in solution caused both the nucleation and growth rates to decrease.
Modeling, analysis, and simulation of bioremediation of soil aggregates
Authors: Dhawan S. , Fan L. T. , Erickson L. E. , Tuitemwong P. 
Published: February 2007

AbstractThe role of aggregates and their characteristics on bioremediation in soil has received very little attention. In this investigation, the contaminated aggregates bioremediation (CAB) model has been developed and simulated to analyze the bioremediation of soil and water in the aggregates. The model equations consist of a system of three non‐linear partial differential equations. Dimensional analysis of the equations has been performed. Sensitivity analysis conducted by numerically solving them has demonstrated the effects of aggregate radius, partition coefficient, and initial contaminant concentration on the time and mechanism of remediation. The rates of diffusion of substrate and oxygen, and the biodegradation‐rate have been found to be the controlling mechanisms for remediation in the aggregates.
Implications of the Clean Air Act acid rain title on industrial boilers
Authors: Maibodi Mehdi 
Published: February 2007

AbstractThis paper discusses the impacts of the 1990 Clean Air Act Amendments related to acid rain controls, as they apply to industrial boilers. Emphasis is placed on explaining the Title IV provisions of the Amendments that permit “nonutility” sources to participate in the SO2 allowance system. The allowance system, as it pertains to industrial boiler operators, is described, and the opportunities for operators to trade and/or sell SO2 emission credits is discussed.The paper also reviews flue gas desulfurization system technologies available for industrial boiler operators who may choose to participate in the system. Furnace sorbent injection, advanced silicate process, lime spray drying, dry sorbent injection, and limestone scrubbing are described, including statements of their SO2 removing capability, commercial status, and costs. Capital costs, levelized costs and cost‐effectiveness are presented for these technologies.