bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of high speed jets and internal baffles on the gas residence times in large municipal incinerators
Authors: Nasserzadeh V. , Swithenbank J. , Schofield C. , Scott D. W. , Loader A. 
Published: February 2007

AbstractThe value of knowing the gas residence times in large municipal incinerators and the serious error imposed by the traditional use of gas volume flow rate based average residence time with regard to these incinerators are recognized. There is increasing public awareness and concern over emissions from municipal solid waste incinerators. Modelling studies of particle trajectories using computational fluid dynamics shows the utility of simulation for the determination of residence time distribution in incinerators. These studies indicate that residence time distributions contain valuable information, important to the understanding and evaluation of mixing processes in the incinerator overfire region. A number of design modifications and changes in operational conditions (which have a major influence on the mean gas residence times and overall performance of two large municipal incinerator plants (35 MW and 65 MW) are proposed. Specifically, the effect of high speed jets and different internal baffle configurations have been investigated using mathematical modelling, in an attempt to obtain optimum combustion conditions. This would increase the mean gas residence times, minimize the emission of pollutants and improve the temperature profile throughout the system. The utility of having detailed RTD information for the incinerator overfire region is demonstrated by estimating the residence times using numerical simulation of tracer injection into the 3‐dimensional reacting flow field of two typical municipal incinerator configurations. The modelling results not only underscore the critical role played by jets in achieving desirable states of mixing in the overfire region but also point to the significance of the geometry effects.This modelling work has yielded important results, all of which clearly could not be experimentally verified at the industrial scale due to practical and cost limitations. Nevertheless, the results guide specific modifications to the design and operation and this new approach will be of considerable use to the incinerator design community.
Cleaning of flue gas from solid waste incinerator plants by wet/semi‐dry process
Authors: Deuster E. V. , Mensing A. , Jiang M. X. , Majdeski H. 
Published: February 2007

AbstractTo meet the high demands on the emission limits required by German environmental regulations, well known wet absorption technology using limestone as reagent has been developed and used for specific application in municipal solid waste incineration. This system integrates two independent absorption sections in a single tower, each operating at a different pH. The process ensures the highest removal rate of harmful gases (HCl, SO2, SO3, HF), particulate, and vaporous fumes of heavy metals from the incineration process. The paper discusses the advantages of the wet process.An improvement on this work has been the development of a combined technology incorporating the advantages of spray dryer and wet scrubbing. This combined technology includes a spray dryer, followed by a suitable particulate collection device, and then by the wet scrubbing stage. The purge stream from the wet scrubbing tower is returned as feed to the spray dryer. The by‐product from the combination process is a completely dry powder. As a result, the need for waste water treatment for the wet scrubber purge stream is eliminated. In addition, the combination system allows low cost limestone to be used as a sorbent while providing an easy to handle, free flowing solid by‐product.This paper describes the details of the system process chemistry, criteria of the gas/liquid mass transfer, and presents the results obtained from pilot plants and commercial plants using these alternative processes.
Pollution prevention strategies for the minimizing of industrial wastes in the VCM‐PVC industry
Authors: Randall Paul M. 
Published: February 2007

AbstractIn many U.S. companies, pollution prevention strategies coincide with economic interests. Typically a company strives to be the lowest‐cost producer, to be competitive, and to reduce wastes. In this paper, the author reviews pollution prevention strategies in the vinyl chloride monomer (VCM)—polyvinyl chloride (PVC) industry, the current process technology and the pollution prevention practices to minimize all types of waste. This paper includes a review of the balanced oxychlorination process, the high temperature chlorination process, new EDC cracking techniques, modified EDC reactor designs, new catalysts, new separation technologies, and other alternative low‐waste process pathways and modifications.
Compliance with NPDES storm water discharge permit requirements
Authors: Diller Jonathan M. 
Published: February 2007

AbstractThe United States Environmental Protection Agency (USEPA) has established the Storm Water Pollution Prevention Plan (SWPPP) as the primary means of regulating the discharge of industrial storm water runoff under the National Pollutant Discharge Elimination System (NPDES) permit program. The SWPPPs are, or will be, a requirement of the facility's NPDES (or state equivalent) permit.Discharge monitoring is currently reserved for only select regulated facilities. These facilities include those subject to EPCRA (SARA) Title III Section 313, land disposal sites and those with other specific categories of industrial activity identified in the regulations. However the permitting authority can, at its discretion, require discharge monitoring for any regulated facility.This paper reviews the requirements for developing and implementing the SWPPPs. Experience obtained from developing the SWPPPs for a wide range of facilities is included. These sites have included commercial and industrial construction sites, regional landfills, small light industrial facilities, and a major industrial complex covering several hundred acres of impervious industrial area.Special focus is given to methods for implementing the SWPPP that can improve the plan's effectiveness in meeting the facility's environmental policy objectives. A brief review of some problems and pitfalls to avoid in compliance monitoring is also included.
SCR catalyst‐coated fabric filters for simultaneous NOx and high‐temperature particulate control
Authors: Ness Sumitra R. , Dunham Grant E. , Weber Greg F. , Ludlow Douglas K. 
Published: February 2007

AbstractThe Energy & Environmental Research Center (EERC) participated in a project with Owens‐Corning Fiberglas Corporation (OCF) to test high‐temperature fabric filters coated using a sol‐gel process with a proprietary form of a vanadium/titanium (V/Ti) catalyst. The catalyst‐coated S‐glass fabric filters are targeted for use in a power plant or industrial hot‐side baghouse facility for simultaneous NOx and particulate control. Issues pertaining to the successful development and marketing of this technology, such as catalyst and filter durability, NOx and particulate control capabilities, ammonia slip levels, and catalyst deactivation were addressed. As part of this project, bench‐scale experiments were performed at the EERC to determine the effects on catalyst reactivity and fabric integrity of 1) suspected selective catalytic reduction (SCR) catalyst poisons typically found in Western coal ash, and 2) exposure to a water or acid dewpoint as a result of an operational upset in a baghouse facility.
Evaluation of brush plated alloys as substitutes for tank plated hard chromium
Authors: Durham Hugh B. , Hooper Ann Marie 
Published: February 2007

AbstractThis paper summarizes results obtained from a test program conducted in cooperation with Tinker Air Force Base (TAFB) in 1993 for the purpose of evaluating the potential of using brush plated alloys as replacements for tank plated hard chromium which is used in the overhaul of jet engines. Test specimens used in this study were fabricated from carbon steel, chromium‐based stainless steel, and nickel‐based stainless steel. Baseline specimens were tank plated with hard chromium or with a soft nickel capped with hard chromium. The specimens were tested for fatigue, thickness, microhardness, Taber wear, and Falex pin and vee block wear. All tests were conducted in accordance with standard procedures of the American Society for Testing and Materials (ASTM). Test results obtained from the baseline specimens were compared with those obtained from specimens which had been coated with the three brush plated layered alloy solutions used in this evaluation. Results of this study show that brush plated alloy coatings appear promising as alternatives to tank plated hard chromium. Some data quality problems were encountered during testing, so at this time, definitive statements concerning the use of brush plating alloys as an acceptable alternative to tank plated hard chromium in critical TAFB maintenance, cannot be made. Although these tests results are not positive for TAFB's operation, users of hard chromium tank plating with less critical applications may find brush plated coatings a suitable alternative.
An industrial wastewater pollution prevention study: Evaluation of precipitation and separation processes
Authors: Chang Li‐Yang 
Published: February 2007

AbstractA water pollution prevention study was performed for two plating processes at Lawrence Berkeley National Laboratory (LBNL). This study included wastewater precipitation process analysis, and evaluation of separation and recycling alternatives. One of the pollution prevention opportunity assessment goals is to reduce and reuse wastewater.From a review of coordination chemistry and a series of precipitation process tests, it was found that treatment with optimized pH and mixing rate, proper coprecipitans (such as iron salts), and chemical dosages were needed to dissociate metal ions from the complexes in the wastewater. In this study, reverse osmosis and ion exchange technologies were also evaluated. A water reclamation analysis with these two technologies was implemented. The analysis projected, that with recycling systems, 33% of the wastewater could be reclaimed.
Waste minimization by process modification
Authors: van der Helm D. U. , High K. A. 
Published: February 2007

AbstractThe goal of this research is to show that source reduction through process modification is a viable technique to minimize process waste. To accomplish this objective, the allyl chloride process was studied. The approach involved three steps: process modeling, selection of source reduction variables and their ranges, and optimization of an economic objective function. The simulator ASPEN PLUS™ was used to model and evaluate the process. Source reduction variables were primarily located through the literature as well as a sensitivity analysis. To find the best value of these process variables, optimization of an economic objective function was performed. The general methodology developed through this work gave structure to this research and was found to be a useful approach in determining economical waste minimization optics.
Stripping of VOC's from dissolved air flotation
Authors: Parker W. J. , Monteith H. D. 
Published: February 2007

AbstractA pilot scale study was performed to assess gas phase emissions of volatile organic compounds (VOCs) from the dissolved air flotation process. A high degree of mass closure was observed in experiments using tapwater dosed with a cocktail of VOCs, indicating that techniques employed to characterize the pilot plant were valid. Subsequent dosed wastewater experiments examined volatilization from a wastewater matrix that contained oils and suspended solids as well as investigating the impacts of hydraulic loading and recycle rate on the fate of the VOCs in the dissolved air flotation unit. Emissions of the dosed candidate compounds, calculated as a percentage of the influent mass flow, ranged from 0.2% of 1,1,2,2‐tetrachloroethane to 9.9% of tetrachloroethylene. Hydraulic loading and compound type had a statistically significant effect on the emissions of VOCs, however, a high degree of interaction between parameters was observed. Effluent recycle had a greater effect on emissions at the higher hydraulic loading than at the lower loading. A model which incorporated stripping by bubbles, volatilization from a quiescent oil‐free surface and equilibrium partitioning to oil was developed. The model was able to simulate the candidate compound response under all experimental conditions except the case with low hydraulic loading and low recycle rate. The results suggest that the surface volatilization model may underestimate emissions. It is hypothesized that the presence of a float in the form of a foamy layer with a high surface area tends to increase liquid‐gas mass transfer of the candidate compounds over that assumed in the surface volatilization model.
Cost‐effective treatment of organic sludges in a high rate bioreactor
Authors: Dhuldhoya Nimish , Lemen John , Martin Bobby , Myers Jim 
Published: February 2007

AbstractThe design and pilot testing of a deep fixed bed/attached growth high rate bioreactor (HRB) for treatment and disposal of refinery oily sludges and biosolids are described. The HRB technology is being jointly developed by Texaco Inc. and Stone & Webster Engineering Corporation to allow for the processing of refinery oily sludges, biosolids, and contaminated soils.A key feature of the technology is its integral combination of dewatering, landfarming, and digestion operations. In essence, the technology operates as a combination of landfarm, aerobic digester, and trickling filter for semi‐solids/sludges. The system provides biological degradation of wastes, and features optimal air, water and/or solids recycling, and ease of maintenance. The technology is covered by three separate patents and is particularly applicable at facilities where regulations, climatic conditions, and/or land availability limit the use of conventional land‐based units.This paper reviews current and proposed regulations pertaining to “land‐banned” wastes, and presents our experience with regard to design and operation of the prototype unit.
Biofiltration of odors, toxics and volatile organic compounds from publicly owned treatment works
Authors: Webster Todd S. , Devinny Joseph S. , Torres Edward M. , Basrai Shabbir S. 
Published: February 2007

AbstractIncreasing federal and state regulation has made it necesary to apply air pollution control measures at publicly owned treatment works (POTWs). Traditional control technologies may not be suitable for treating the low and variable contaminant concentrations often found in POTW off‐gases. An alternative control technology, biofiltration, was studied. An experiment using bench‐ and pilot‐scale reactors established optimal operating conditions for a full‐scale conceptual design. The waste airstream contained ppmv levels of hydrogen sulfide and ppbv levels of specific volatile organic compounds (VOCs). Granular activated carbon (GAC) and yard waste compost (YWC) were tested as possible biofilter media with and without pH control. The 16‐month field study bench reactors achieved 99% removal of hydrogen sulfide, 53 to 98% removal of aromatic hydrocarbons, 37 to 95% removal of aldehydes and ketones, and 0 to 85% removal of chlorinated compounds. The GAC and YWC pilot reactors removed more than 80% and 65% of the total VOCs at 17 second and 70 second empty bed retention times, respectively. The YWC reactors performed poorly at empty bed retention times of 30 and 45 seconds, removing less than 40% of total VOCs. Declining pH had little negative effect on contaminant removal, suggesting costly control measures may not be necessary. Biofiltration appears to be a feasible alternative to traditional control technologies in treating offgases from POTWs.
Development of a new electrokinetic technique for decontamination of hexavalent chromium from low surface charged soils
Authors: Haran Bala S. , Popov Branko N. , Zheng Guanghong , White Ralph E. 
Published: February 2007

AbstractA new in‐situ technique was developed for hexavalent chromium removal from sand. Imposition of constant potential gradient across the soil matrix through a graphite cathode and iron anode resulted in successful migration of chromate towards the anode. The hexavalent chromium ions are reduced to harmless trivalent form by chemical reaction with the anodic dissolution product, Fe2+.
Soil washing enhancement with solid sorbents
Authors: El‐Shoubary Y. M. , Woodmansee D. E. 
Published: February 2007

AbstractSoil washing is a dynamic, physical process that remediates contaminated soil through two mechanisms: particle size separation and transfer of the contaminant into the (mostly) liquid stream. The performance of different sorbents and additives to remove motor oil from sea sand was tested. Hydrocyclone, attrition scrubber, and froth flotation equipment were used for the decontamination study. Sorbents and additives were mixed with soils in the attrition scrubber prior to flotation. Sorbents used were granular activated carbon, powder activated carbon, and rubber tires. Chemical additives used were calcium hydroxide, sodium carbonate, Alconox®, Triton® X‐100 and Triton® X‐114. When a froth flotation run was performed using no additive, washed soils “tails” contained 4000 ppm of total oil and grease (TOG). However, when carbon or rubber (6% by weight) was added to the contaminated soils the washed soils “tails” contained less than 1000 ppm of total oil and grease (TOG). The addition of sodium carbonate or calcium hydroxide (6% by weight) had same effects as sorbents. In both cases washed soil “tails” contained total oil and grease of less than 1000 ppm. The use of these non‐hazardous additives or sorbent can enhance the soil washing process and consequently saves on time (residence time in equipment) and number of stages (equipment design) required to achieve the target clean up levels.
The Carver‐Greenfield Process: Dehydration/solvent extraction technology for waste treatment
Authors: Trowbridge Theodore D. , Holcombe Thomas C. 
Published: February 2007

AbstractA combination dehydration/solvent extraction treatment technology, the proprietary Carver‐Greenfield (C‐G) Process, can be used to separate solid/liquid waste materials into three separate product streams convenient for reuse or disposal:

clean, dry solids suitable for fixation of non‐hazardous landfilling;
water virtually free of solids and oils which can be processed in an industrial or public wastewater treatment facility; and,
oil indigenous to the feed, a mixture of extracted hydrocarbon‐soluble compounds which typically includes any hazardous contaminants which are present.
As normally practiced, this dehydration/solvent extraction technology involves slurrying water‐wet waste in a hydrocarbon solvent which extracts indigenous oil from contaminated solid particles and concentrates it in the solvent phase. Dehydration also takes place during the treatment; water is evaporated and condensed as a separate product. Dry solids are reslurried in fresh solvent one or more additional times depending on the degree of extraction required. Extracted solids are centrifuged away from the solvent and residual solvent in the centrifuge cake vaporized off the final product solids stream in a desolventizer. Indigenous oil from the waste is separated from the solvent by distillation with recovered solvent being recycled to the process.For commercial applications, this process is very flexible in its ability to be efficiently adapted to waste processability and treatment objectives. For example, if the contaminants are very heavy organics like PCB's, they may be further concentrated in a portion of the indigenous oil such that only a very small highly concentrated contminant stream need be disposed of and uncontaminated oil may be recovered for a process credit. In some cases where the feed has a high water concentration, the dry solids need not be separated from the indigenous oil but they can be recovered/disposed of together.This dehydration/solvent extraction technology has been licensed to over 80 facilities over the past 30 years to solve waste disposal problems in a wide variety of fields. More than half of the plants were designed to dry and deoil slaghterhouse wastes (in rendering plants). The other units are used to evaporate water and extract indigenous oil from a broad spectrum of other materials, including municipal and industrial sewage sludges, wool scouring wastes, petrochemical sludges, wood‐pulp waste, pharmaceutical wastes, dairy and food products, textile wastes and animal manure.This paper discusses the C‐G Process flexibility and economics as applied to various hazardous waste examples including PCB contaminated sediments, soils and sludges, spent drilling fluids (U.S. EPA SITE Program), refinery wastes, manufactured gas plant (MGP) sites, etc.
Removing a small quantity of THT from gas storage groundwater through air stripping and gas‐phase carbon adsorption
Authors: Girod J. F. , Leclerc J. P. , Muhr H. , Paternotte G. , Corriou J. P. 
Published: February 2007

AbstractThis paper deals with the response to a case of contaminated groundwater located in France. The natural gas is stored during summer in porous underground rocks. When energy requirements increase (particularly in winter), gas is drawn off, but water is also pumped during this operation. The water has a strong characteristic odour of the TetraHydroThophene (THT), which has been used by Gaz de France as an additive in order to detect gas leakages because of its strong odour. Unfortunately, the presence of THT in medium other than natural gas can be responsible for safety problems. Gas stripping combined with adsorption on granular activated carbon was chosen to obtain removal of THT from the groundwater. The gas to water ratio for stripping column is higher than usual and the gas used for stripping was recycled in order to prevent air pollution. Carbon consumption is approximately 3 tons a year.
A practical guide for determining the solubility of metal hydroxides and oxides in water
Authors: Dyer James A. , Scrivner Noel C. , Dentel Steven K. 
Published: February 2007

AbstractIn response to increasing metal toxicity concerns, new and more stringent regulations are driving industry to better understand the fate of metals in the environment. As a result, practicing engineers need a set of tools for quickly understanding the aqueous chemistry of the system at hand. This paper presents a practical guide for estimating the solubility of metal hydroxides/oxides in aqueous systems. Equilibrium chemistry software from OLI Systems, Inc. (Morris Plains, NJ) was used to predict the solubility of metal hydroxides/oxides in water as a function of pH. The product is an overall metal solubility diagram containing the solubility curves for 12 metal hydroxides/oxides. The curves are based on a commercially available thermodynamic database and were validated against literature solubility data. In most cases, the curves depict the solubility of the less stable crystalline or amorphous form of the metal hydroxide or oxide. This will be typical of industrial situations where aging of the solid phase is often minimal. The solubility curves are best viewed as “solubility bands” that can extend as much as an order of magnitude above and below the predicted lines. Two case studies illustrate the usefulness of the overall metal solubility diagram to practicing engineers.