bluuebunny/crossref_metadata_2025 huggingface dataset:
Mercury reduction in products and processes: A review of the electrical and electronic industries
Authors: Randall Paul M.
Published: February 2007

The 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

The 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

This 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

About 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

This 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

The 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

A 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

Identifying 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

Controlling 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

Although 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

In 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

The 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

An 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

Nonconvective (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

Several 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

Dissolved 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.
Biological conversion of hydrogen sulfide into elemental sulfur
Authors: Basu R. , Clausen E. C. , Gaddy J. L.
Published: February 2007

Currently, 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

Bench‐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

The 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

Preliminary 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

During 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

A 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

The 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

Calcium 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

Life 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

An 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

Knowledge 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

Regulated 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

Studies 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

Three 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

Pure 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

Many 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

The 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

Software 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.