bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mercury reduction in products and processes: A review of the electrical and electronic industries
Authors: Randall Paul M. 
Published: February 2007

AbstractThe electrical and electronics industries have significantly reduced the amount of mercury from various products and processes. However, the unique electromechanical and photoelectronic properties of mercury and mercury compounds have made replacement of mercury difficult in some applications. This paper identifies many of the source reduction and recycling alternatives for mercury in electrical and electronic applications and reviews the usage trends for mercury in the U.S. Data suggests that U.S. companies have clearly decreased the amount of mercury over the past 10 years; the most significant change has occurred in batteries with a 99% decline in mercury use. For products where the photoelectronic properties of mercury are important (e.g., electric lighting), a recycling infrastructure is developing. One potential problematic area may be the use of mercury in semiconductors where mercury may be difficult to recycle and may generate a large quantity of waste relative to mercury use.
Pollution prevention applications in construction and water resource management
Authors: Houthoofd Janet M. 
Published: February 2007

AbstractThe article discusses selected pollution prevention applications and opportunities in the fields of construction and water resource management, fields with which the term “pollution prevention” is not typically associated. The article targets an audience composed of professionals who have an interest in these fields and begins by presenting a brief background on pollution prevention with this audience in mind. How pollution prevention principles and practices may be incorporated into construction and water resource management is then discussed. The main themes touched upon fall into the categories of conservation of resources, thoughtful and efficient design, use of recycled materials in construction, life‐cycle considerations, and sustainable development. Several major work areas within the overall scope are selected for more detailed development to demonstrate the application of pollution prevention principles. Areas of emphasis include building design and construction, pavements, highways, bridges, stormwater management, wastewater reuse, and pipeline construction. A literature review style is used to briefly present substantial portions of the information.
Review of solvent cleaning in aerospace operations and pollution prevention alternatives
Authors: Stone Kenneth R. , Springer Johnny 
Published: February 2007

AbstractThis paper examines the use of selected solvents in degreasing, cold cleaning and spot cleaning applications in the aerospace industry, with emphasis on Federal facility operations. Research referenced in this paper is drawn from aerospace industry participants and from research conducted under the Strategic Environmental Research and Development Program (SERDP), as well as EPA's Waste Reduction Evaluations At Federal Sites (WREAFS) program. SERDP is a cooperative effort between DoD, DOE and EPA to develop environmental solutions that enhance mission readiness in defense operations. WREAFS, founded in 1988, is an EPA‐backed program that works with individual military bases, research centers and Federal facilities to promote pollution prevention opportunities and advance technologies to reduce environmental impacts while enhancing efficiency in Federal operations.With the increasing regulatory pressure preceded by the Clean Air Act, Montreal Protocols and various Executive orders, the use of certain highly effective, but environmentally harmful solvents has been restricted and will likely be further limited in the future. In the aerospace industry, primary solvents are also found on EPA's 33/50 list—often referred to as the “EPA 17” list—of hazardous chemicals identified for reductions. With the added concerns of customer demand, market forces and costs, participants in both the private and public sector components of the aerospace industry and operations are moving to find replacements for the targeted chemicals. Various strategies are being considered, both chemical and mechanical in nature. The purpose of this paper will be to select some of the primary solvents and evaluate promising alternative chemicals and cleaning operations currently available. It will also provide a briefing on some alternatives currently being evaluated at Federal facilities.
Microbial sweetening of sour natural gas using mixed cultures
Authors: Rai Charanjit , Taylor Martin 
Published: February 2007

AbstractAbout twenty‐five percent of natural gas produced in the United States is sour containing significant volumes of hydrogen sulfide. Liquid redox processes remove hydrogen sulfide from natural gas. Aqueous solution of chelated ferric ions oxidize the hydrogen sulfide to elemental sulfur. The reduced iron chelate is then oxidized by contact with air and recycled. This requires expensive equipment for regeneration and the process is usually energy intensive.A microbial process for regeneration of chelated ferric ions may offer an economical alternative to commercial liquid redox processes. The present study investigates the use of a mixed culture of iron oxidizing bacteria to regenerate commercial iron chelate catalysts. The objective of this study is to quantify an increase in the biologically enhanced redox solution reoxidation rates. It was observed that the presence of bacterial cultures enhance the reoxidation rates and sulfur removal significantly. The proprietary mixed cultures of iron oxidizing bacteria used in this study derive the energy required for their growth from the oxidation of reduced sulfur compounds and from the oxidation of Fe(II) to Fe(III) ions in presence of air.A series of experiments were conducted with a commercial chelated iron catalyst at a constant pH of 7.5 using a total iron concentration of 1000 ppm in the solution. Regeneration of the solution was carried out by passing air through the solution. Sulfur produced was removed by centrifuging in the case of baseline experiments and by vacuum filtration in the presence of bacteria. A 50 to 125% increase was observed in the regeneration rates whereas sulfur yields were 80 to 100% of theoretical in the presence of bacteria as compared to 35 to 50% in the absence of bacteria. Iron oxidizing bacteria were used at cell densities of 1.5 × 109 cells/l to be effective. The pH of the redox solution was observed to be a key process parameter. Other parameters such as temperature, total iron concentration, gas to liquid ratio and bacterial cell densities also influence the overall process.
Preparation and evaluation of adsorbents from waste carbonaceous materials for SOx and NOx removal
Authors: (Max) Lu G. Q. 
Published: February 2007

AbstractThis paper presents studies of a new integrated process for simultaneous SOx and NOx removal and utilization of waste carbonaceous materials. It is mainly centered on some fundamental aspects of preparing microporous adsorbents from solid wastes such as coal reject, sewage sludge and sawdust. Surface area and pore structural evolution are investigated to illustrate the importance of processing parameters such as pyrolysis temperature and hold time, activation methods and carbon burn‐off, etc. It is shown that pyrolysis temperature, activation chemicals used and carbon burn‐off have significant effects on the surface area development and pore structure evolution. There exist an optimal pyrolysis temperature and hold time for maximum surface area development for all precursor materials. Physical activation of coal reject char after pyrolysis can improve the surface area of the derived chars, while chemical treatment in ZnCl2 can enhance the microporosity of sewage sludge char. In physical activation, carbon burn‐off or hold time is a critical factor in determining the surface area. Concentration of the activating agent is an important factor in chemical treatment of sewage sludge. Adsorption characteristics of the wastes‐derived adsorbents with respect to SO2, H2S, and NOx are also studied in this work. It is shown that solid wastes such as sawdust and coal mining wastes can be converted into effective adsorbents for SO2 and NOx removal from the flue gases, whilst activated chars derived from sewage sludge have been shown to be promising adsorbents for H2S removal. The significance of using waste solids is two‐fold: on one hand the waste materials are utilized or minimized; on the other, they can replace or partially substitute the expensive activated carbons for the removal of SOx and NOx.
An accurate Predictive Emissions Monitoring System (PEMS) for an ethylene furnace
Authors: Cheng Aaron M. , Hagen Guy F. 
Published: February 2007

AbstractThe Predictive Emissions Monitoring System (PEMS) has been recently proposed as an alternative to hardware continuous emissions monitors (CEM). PEMS has two distinct advantages over hardware CEM: much lower costs to install and maintain, and ability to provide information on emissions under various conditions. Using a state‐of‐the‐art computer program, an accurate PEMS was developed for an ethylene furnace at Exxon Chemical Company's Baytown Olefins Plant, Baytown, Texas. First, a test plan was carefully designed to collect furnace process and stack emissions data over the total operating range of the furnace. The emissions data (NOx, O2 and CO) were collected and measured by an independent company for 5 days. The related process data were recorded in the DCS system during the same 5‐day period. A dataset with some 7,000 patterns of related process and emissions data was generated. The PEMS system contains 2 parts: emissions prediction and sensor validation models. The main purpose of the sensor validation model is to validate the input sensor's raw data and reconstruct new sensor values, if necessary, before they are used in the prediction model. Its usage provides a high degree of confidence for the PEMS system. Two separate emissions prediction models were built, one for NOx and O2, and the other for CO. Both final models have the same 9 input sensors. A PEMS relative accuracy test audit (RATA) was performed by an independent company to test the PEMS system under the three firing rate conditions (low, medium, and high). Test results indicate that the PEMS system satisfied both the relative accuracy (RA) and the stringent statistical test requirements including the F‐test, t‐test and r‐correlation.
Analysis of non‐isothermal, wet oxidation reactor data
Authors: Hochleitner Wolfgang A. 
Published: February 2007

AbstractA batch reactor designed to simulate the non‐isothermal temperature profile of a commercial, vertical‐tube wet oxidation process is used to predict global process performance, and to estimate reaction rates. A model is developed for the batch reactor that predicts extent of reaction and vapor/liquid equilibria under non‐isothermal conditions. This model is used with measured rate parameters to predict the effect of process conditions on overall performance of specific wastes. This reduces the number of runs normally executed in a feasibility study, saving time and money. Phenol is selected as a model compound, and values for reaction rate constants and induction period length are obtained for temperatures up to 224°C.
Design for pollution control: Screening alternative technologies
Authors: Spriggs H. D. , Smith William R. 
Published: February 2007

AbstractIdentifying potential solutions to complex problems using a minimum of information is important in a wide range of circumstances. Tools for this purpose are key to sound decisions and require careful thought and implementation. This article describes the development and use of a screening tool to allow a utility, Houston Lighting & Power Company, to provide technical support to its process industry customers. The objective is to provide advice to these companies regarding cost and energy efficient technologies which can address this industry's environmental and other processing problems.
Mass transfer of volatile organics from large open basins
Authors: Sadek Shafik E. , Smith J. Donald , Watkin Andrew T. , Gebel Rolf 
Published: February 2007

AbstractControlling the volatilization of organic compounds from treatment works is becoming increasingly important as the definition of industrial categorical standards for air emissions by the EPA draws nearer. In this light, specific volatilization rates of several volatile organic compounds (VOC's) contained in multimillion gallon retention (“equalization basins”) and settling (“primary clarifier”) basins were measured using a flux chamber technique, a method used by the EPA for emission measurement. In this method, the liquid surface within an enclosing chamber is swept with air at a measured rate and the gas is analyzed. The mass transfer coefficients derived from these VOC vaporization rates were equal for the primary clarifier and the equalization basins. Factors were estimated to correct for the different ambient wind conditions to which these basins are exposed. Also it was determined that the rate of volatilization of VOC's with low Henry's law constants may be underestimated by the measurement. This is a result of the gas‐phase resistance being dominant under the test conditions and the liquid‐phase resistance being dominant under normal ambient conditions, and of the assumption that the liquid‐phase resistance remains unchanged under both test and ambient conditions. The particular organics studied were acetone, methyl ethyl ketone, methyl isobutyl ketone, isopropanol, methanol and toluene.
Field evaluation of a granular activated carbon fluid‐bed bioreactor for treatment of chlorobenzene in groundwater
Authors: Klečka G. M. , McDaniel S. G. , Wilson P. S. , Carpenter C. L. , Clark J. E. , Thomas A. , Spain J. C. 
Published: February 2007

AbstractAlthough granular activated carbon (GAC), fluidizedbed bioreactors have been used for treatment of groundwater containing readily biodegradable organic compounds, there is only limited experience with treatment of chlorinated organics found at many industrial sites. This paper describes a field evaluation of a GAC fluid‐bed bioreactor operated at various chlorobenzene concentrations and organic loading rates over a 7‐ month period. Microorganisms used to seed the bioreactor were provided by activated sludge from the site, as well as indigenous chlorobenzene‐degrading bacteria present in the groundwater. Removal efficiencies exceeding 99.99% were achieved at organic loading rates between 6 and 10 pounds of total oxygen demand (lb TOD) per 25 cubic feet per day. Influent chlorobenzene concentrations ranging from 100 to 170 ppm were consistently reduced to below the detection limit of 10 ppb. Economic evaluation indicates that groundwater treatment costs for the bioreactor were lower than other conventional technologies.
The first full‐scale soil washing project in the USA
Authors: Mann Michael J. , Groenendijk Erik 
Published: February 2007

AbstractIn mid‐1992, Geraghty & Miller, Inc. and Heidemij Realistie of The Netherlands incorporated the joint venture of Alternative Remedial Technologies, Inc. (ART) to implement soil washing projects in the United States. The venture was based upon Heidemij's successful commercial soil washing operations in The Netherlands over the past decade. The first project contracted under this arrangement was the King of Prussia (KOP) Technical Corporation Superfund site, located in Camden County, New Jersey. This paper presents the details of activities at this site and operation of the full‐scale soil washing facility. At the KOP site approximately 20,000 tons (20,320 metric) of soil contaminated with copper, chromium and nickel were remediated. The KOP plant is rated at 25 (25.4 metric) tons per hour (tph) and is configured in a way that allows flexible treatment capabilities for sites with metals, polynuclear aromatics, pesticides, and radioactive contamination.
Scale‐up and economic analysis for the design of supercritical fluid extraction equipment for remediation of soil
Authors: Montero G. A. , Giorgio T. D. , Schnelle K. B. 
Published: February 2007

AbstractThe magnitude of the contaminated site clean‐up in the United States indicates the need for more effective, less costly remediation technologies. Supercritical Fluid Extraction (SFE) using carbon dioxide (CO2) as a supercritical fluid is a possible alternative technology for remediation of soils contaminated with volatile organic compounds. The feasibility of this process is mainly dependent on two factors: the extent and extraction rate of heavy molecular weight organic compounds from soil by supercritical carbon dioxide (SC‐CO2). This paper presents results of a bench‐scale study for remediation of soils contaminated with naphthalene and 1,2,4 trimethyl benzene as a function of the flow rate (Qco2) and supercritical fluid density (ρ co2). These data are used to perform a basic economic analysis of the process by using these two organics selected as model soil contaminants.An additional aim of this study was to develop scale‐up methodology from laboratory SFE devices to industrially useful equipment. Laboratory scale data, such as mass transfer coefficients, have implications for the sizing and control of process units including reactors and separation columns since high mass transfer rates allow smaller reactors. Furthermore, this study included the collection and analysis of the experimental data to support the application of the supercritical fluid extraction technology and to provide the conceptual design and operational processes required for the construction of a pilot plant unit.The experimental data were presented as an outlet concentration profile of solute (naphthalene or 1,2,4 trimethyl benzene) desorption at different flow rates. This qualitative analysis of the desorption experiments suggested that a promising model should include external and intraparticle mass transfer and be based upon equilibrium at a desorption site. Thus, a simulation has been performed using an equilibrium desorption model [1] and fitted using MATHEMATICA® software (version 2.2.2). Finally, a preliminary economic analysis using these results showed that the proposed process (SFE) is feasible for soils contaminated with two different pure (naphthalene or 1,2,4 trimethyl benzene) hazardous organics as a model system.
Removal of nitric oxide from flue gas with iron thiochelate aqueous solution in a turbulent contact absorber
Authors: Shi Yao , Littlejohn David , Kettler Peter B. , Chang Shih‐Ger 
Published: February 2007

AbstractAn iron(II) thiochelate has been developed for use as an additive in a wet flue gas scrubber for simultaneous removal of SO2 and NOx from flue gas. The additive enhances the solubility of NO in scrubbing liquor by binding NO to form an iron nitrosyl thiochelate. The effect of oxygen on NO absorption in iron(II) thiochelate aqueous solutions, as well as in iron(II)(EDTA) solutions, has been studied. The results showed that the iron(II) thiochelate is more resistant to oxidation by oxygen than the conventional iron(II)(EDTA) additive. Parametric studies of the absorption efficiency of NO were performed in a bench‐scale Turbulent Contact Absorber (TCA). Based on the bench‐scale test results, a prediction of the performance of a full‐scale spray absorber has been made.
Nonconvective movement of VOCs in moist soil
Authors: Cabbar H. Canan , McCoy Ben J. 
Published: February 2007

AbstractNonconvective (stationary) diffusion of a volatile organic compound (VOC) in unsaturated (moist) soil depends on the effective diffusion coefficient for the gas filled voids and on the retardation factor, expressed in terms of the adsorption capacity of the soil particles. Influenced by the water layers partially covering organic and mineral surfaces, the sorptive capacity was assumed to be caused by linear adsorption at the air‐water interface, at the water‐organic and water‐mineral interfaces, and at the gas‐organic and gas‐mineral interfaces. To a lesser extent, the particle porosity and the solubility of the VOC in the water also can affect partitioning. By means of temporal moment and volume averaging methods, mathematical expressions for these effects were developed and evaluated for moist soils of porous and nonporous particles. This approach was successful in interpreting experimental data for equilibrium adsorption coefficients from different sources.
Design of a UV oxidation system for treatment of TCE‐contaminated groundwater
Authors: Weir Barbara A. , McLane Cinthia Rudasill , Leger Robert J. 
Published: February 2007

AbstractSeveral design issues were encountered by EPA and Metcalf & Eddy during the design of a UV oxidation system for treatment of TCE‐contaminated groundwater at the Groveland Wells Superfund Site. The issues included: (1) the need to execute treatability studies of the UV oxidation technology, as required by the Record of Decision, to provide data needed to develop a more accurate design and cost estimate; (2) the need to evaluate pretreatment options for removal of inorganics prior to UV oxidation, both to minimize maintenance problems and to ensure that applicable discharge limits for metals would be met; (3) the need to evaluate measures for ensuring that residual oxidant(s) in the effluent from the UV oxidation system would not cause the effluent to exceed toxicity limits for discharge to surface water, and (4) the need to develop a performance specification for the UV oxidation system which would ensure fair competition among vendors of UV oxidation systems, while also ensuring that EPA would receive a system which was cost‐efficient and able to meet discharge limits.Metcalf & Eddy competitively procured a UV oxidation vendor to perform bench‐scale treatability studies on site groundwater and designed a pretreatment system consisting of an equalization tank, inclined plate clarifier, and dual media filters. The specification for the UV oxidation system was written to allow the UV oxidation vendor maximum flexibility while still ensuring that discharge limits for VOCs of concern and toxicity are met. The specification allows for the use of hydrogen peroxide, ozone, or a combination of the two as the oxidant and requires that the effluent not exceed toxicity limits. The vendor is allowed to meet toxicity limits either by using oxidant concentrations that result in a non‐toxic residual, or by installing a module to reduce residual oxidant concentration(s) to non‐toxic levels before discharge. This approach allows the vendor to use process alternatives that result in an overall system which minimizes costs.
Macro porous polymer separates hydrocarbons from water with simple, effective, dependable liquid‐liquid extraction
Authors: van der Meer A. B. , Brooks Paul E. 
Published: February 2007

AbstractDissolved hydrocarbons are effectively removed from ground‐ and process water by liquid/liquid extraction using a Macro Porous Polymer (MPP) System. The hydrocarbons transfer from water to a favored organic substrate, which is immobilized in the cells of a Macro Porous Polymer. Cleaned water exits the extraction column while hydrocarbons are retained in the extraction medium. The hydrocarbon‐laden extraction medium is regenerated in‐situ with low‐pressure steam, which volatizes the hydrocarbons but not the extraction fluid. Regenerated extraction medium is returned to water service. Extraction fluid does not leach into treated water. Volatized hydrocarbons are condensed and separated for disposal or re‐use. For relatively high mass loadings and rigorous effluent requirements, the MPP system offers lower operating cost than carbon adsorption and lower investment cost than steam stripping. Field data verify process performance and economics.